A new study from <a href="https://www.osu.edu/">Ohio State University</a> reveals what is going on inside of your <a href="https://www.earth.com/news/gut-brain-interactions-have-an-influence-on-diseases/">brain</a> when you get lost in a fictional fantasy. The experts discovered that the more immersed we become in the lives of our favorite characters of fiction, the more our brain activity reflects how much we identify with them.
&#8220;When they think about a favorite fictional character, it appears similar in one part of the brain as when they are thinking about themselves,&#8221; said study lead author Timothy Broom.
The research was focused on self-described fans of the HBO series &#8220;Game of Thrones.&#8221; The individuals were instructed to think about themselves, nine of their friends, and nine characters from the drama series. The participants also reported on which character they felt closest to and liked the most.
According to Broom, Game of Thrones was ideal for this study because it attracted a devoted fan base and the large cast presented a variety of characters that people could become attached to.
One of the key findings involved participants who scored highest on &#8220;trait identification.&#8221; These individuals agreed most strongly with statements like &#8220;I really get involved in the feelings of the characters in a novel.&#8221;
&#8220;People who are high in trait identification not only get absorbed into a story, they also are really absorbed into a particular character,&#8221; said Broom. &#8220;They report matching the thoughts of the character, they are thinking what the character is thinking, they are feeling what the character is feeling. They are inhabiting the role of that character.&#8221;
The researchers used an fMRI machine to measure activity in various parts of the brain through small changes in blood flow. As the participants&#8217; brains were scanned, they were evaluating themselves, their friends, and Game of Thrones characters. 
A part of the brain called the ventral medial prefrontal cortex (vMPFC) is known to show increased activity when people think about themselves and, to a lesser extent, when they think about close friends.
While in the fMRI, the individuals were shown a series of names &#8211; including themselves, friends, or characters &#8211; along with a trait, such as lonely, sad, trustworthy, or smart. The participants simply said &#8220;yes&#8221; or &#8220;no&#8221; to imply whether the trait fit the person.
As expected, the vMPFC was most active when people were evaluating themselves, less active when they evaluated friends, and least active when they evaluated characters from Game of Thrones.
However, among those who were high in trait identification, the vMPFC was more active when they thought about the fictional characters than it was for participants who identified less with the characters. This region of the brain was particularly active when the individuals evaluated the character they identified with the most.
Study co-author Dylan Wanger said the findings help explain how fiction can have such a big impact on some people.
&#8220;For some people, fiction is a chance to take on new identities, to see worlds though others&#8217; eyes and return from those experiences changed,&#8221; said Wagner.
&#8220;What previous studies have found is that when people experience stories as if they were one of the characters, a connection is made with that character, and the character becomes intwined with the self. In our study, we see evidence of that in their brains.&#8221;
The study is published in the journal <a href="https://academic.oup.com/scan">Social Cognitive and Affective Neuroscience</a>.
&#8211;&#8212;
By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

What happens in your brain while you're lost in fiction

A pair of objects 20,000 light‑years away has just broken the energy ceiling for light inside our galaxy. These twin bodies (a massive star and a black hole), known as a microquasar, are generating cosmic rays containing photons with more energy than any previously seen from within the Milky Way.



The binary system <a href="https://www.aavso.org/vsots_v4641sgr" target="_blank" rel="noreferrer noopener">V4641 Sagittarii</a> has fired photons above 200 <a href="https://lhc-machine-outreach.web.cern.ch/lhc_glossary.htm" target="_blank" rel="noreferrer noopener">tera­electron­volts (TeV)</a>, turning a once‑obscure star‑black‑hole partnership into a new “cosmic ray monster.”



<a href="https://www.researchgate.net/profile/Sabrina-Casanova-3" target="_blank" rel="noreferrer noopener">Dr.  Sabrina  Casanova</a> of the <a href="https://www.ifj.edu.pl/en/" target="_blank" rel="noreferrer noopener">Institute of Nuclear Physics</a> of the Polish Academy of Sciences helped spot the outburst.



<h2 class="wp-block-heading" id="h-understanding-microquasars-the-basics">Understanding microquasars - the basics</h2>



Stellar systems that mimic the behavior of quasars on a much smaller scale are known as microquasars. They consist of a normal star orbiting a compact object, usually a black hole or <a href="https://www.earth.com/news/fast-radio-bursts-traced-to-chaotic-magnetospheres-of-neutron-stars/">neutron star</a>, which pulls matter from its companion. 



As the material spirals inward, it forms an accretion disk that heats up and emits intense X-rays. At the same time, twin jets of high-energy particles shoot out from the poles at nearly the speed of light. 



This jet activity, driven by the interplay of magnetic fields and extreme gravity, resembles what we see in <a href="https://www.earth.com/news/enough-water-to-fill-trillions-of-earths-oceans-found-circling-black-hole-quasar/" target="_blank" rel="noreferrer noopener">distant quasars</a>, but within our own galaxy.



Astronomers value microquasars because they offer a close-up view of processes that govern much larger and more distant cosmic phenomena. 



Observations of their rapid changes in brightness and jet structure provide insight into the mechanics of black hole accretion and relativistic jet formation. 



Unlike quasars, which exist in distant galaxies and evolve over millions of years, microquasars can change on timescales of days or hours.



<h2 class="wp-block-heading" id="h-microquasars-and-cosmic-rays">Microquasars and cosmic rays</h2>



V4641 Sagittarii sits in the direction of the <a href="https://www.constellation-guide.com/constellation-list/sagittarihttps://www.constellation-guide.com/constellation-list/sagittarius-constellation/us-constellation/" target="_blank" rel="noreferrer noopener">Sagittarius constellation</a> but, unlike distant quasars, it belongs to the Milky Way. 



Because this microquasar - a stellar‑mass black hole that is siphoning gas from a companion star - lies thousands, not millions, of light‑years from Earth, telescopes can track its jets in real time.



High‑energy jets from such local sources let researchers watch particle factories evolve over days instead of over geological time spans. 



That immediacy gives fresh leverage for testing models that were built largely on blurred views of far‑off <a href="https://webbtelescope.org/contents/articles/what-are-active-galactic-nuclei" target="_blank" rel="noreferrer noopener">active galactic nuclei</a>. It also forces a rethink of where the most energetic charged particles in our galaxy actually come from.



<h2 class="wp-block-heading" id="h-microquasars-are-small-but-mighty">Microquasars are small but mighty</h2>



The system’s <a href="https://www.earth.com/news/largest-oldest-black-hole-jet-ever-seen-is-size-of-three-milky-ways-j1601-3102/">black hole</a> weighs the same as about six Suns, while the donor star tips the scale at roughly three. Every 2.8 days they swing around a common center of mass, carving spiral streams of gas that feed an accretion disk no wider than the orbit of Mercury.



Magnetic fields near the hole’s poles launch twin plasma jets that are hundreds of light‑years long; one points almost straight toward us, producing apparent super‑luminal motion nine times faster than light.



“We have observed something quite incredible … photons coming from a microquasar lying in our galaxy and yet carrying energies tens of thousands of times higher than typical!” exclaimed Dr. Casanova. 



Until now, photons from microquasars rarely topped a few tens of giga­electron­volts. 



That jump means that V4641 Sagittarii can accelerate particles to within a factor of two of the energies reached at the <a href="https://home.cern/science/accelerators/large-hadron-collider" target="_blank" rel="noreferrer noopener">Large Hadron Collider</a>, but without the need for an underground ring.



<h2 class="wp-block-heading" id="h-hawc-caught-the-monster-cosmic-rays">HAWC caught the monster cosmic rays</h2>



The High‑Altitude Water Cherenkov Observatory <a href="https://www.sciencedirect.com/science/article/abs/pii/S0168900223002437" target="_blank" rel="noreferrer noopener">(HAWC)</a> in Mexico uses 300 steel tanks filled with clear water and instrumented with four photomultiplier tubes apiece.



When a gamma ray from space strikes the upper atmosphere it triggers a cascade of particles that race through the tanks faster than light can traverse water, producing the familiar blue <a href="https://www.energy.gov/ne/articles/cherenkov-radiation-explained" target="_blank" rel="noreferrer noopener">Cherenkov radiation</a>. 



HAWC records roughly 25,000 air showers every second and reconstructs their direction with degree‑scale precision.



For V4641 Sagittarii, repeated passes over the zenith added up to a clear, persistent signal extending past 200 TeV. Those energies dwarf the trillion‑electron‑volt photons that once defined the upper end of the gamma‑ray spectrum.



<h2 class="wp-block-heading" id="h-what-pushes-the-energy-ceiling">What pushes the energy ceiling</h2>



At 200 TeV, electrons would cool too fast to survive the trip down the jet, implying that protons, or even heavier ions carry the load. 



Shock fronts inside the outflow likely operate like natural synchrotrons, flinging charged particles back and forth across magnetic discontinuities until they outrun <a href="https://www.earth.com/news/high-energy-cosmic-rays-could-arise-from-the-magnetic-chaos-during-black-hole-formation/">energy</a> losses. 



Similar physics was glimpsed in <a href="https://inspirehep.net/literature/2843616" target="_blank" rel="noreferrer noopener">SS 433</a>, another microquasar whose lobes shine at tens of TeV.



But V4641 Sagittarii’s harder spectrum suggests even more efficient acceleration, perhaps boosted by its nearly face‑on jet orientation. 



Ultra‑energetic protons can collide with local gas or starlight near the jet, spawning neutral pions that promptly decay into the detected gamma rays.



<h2 class="wp-block-heading" id="h-fresh-look-at-cosmic-rays">Fresh look at cosmic rays</h2>



For over a century, supernova remnants were cast as the main producers of galactic cosmic rays, a narrative launched when <a href="https://timeline.web.cern.ch/victor-hess-discovers-cosmic-rays-0" target="_blank" rel="noreferrer noopener">Victor Hess</a> rode a balloon to three miles and found ionizing radiation rising with altitude. 



The HAWC result shows that compact binaries can also fill the high‑<a href="https://www.earth.com/news/nuclear-fusion-milestone-brings-clean-energy-closer-to-reality/">energy</a> end of the spectrum, joining supernova shocks and pulsar wind nebulae in the accelerator club.



Support comes from China’s Large High Altitude Air Shower Observatory, which has begun spotting 100 TeV photons from other microquasars. 



If many such systems point their jets even partly toward Earth, their combined contribution could rival that of supernovae above 10 TeV. 



That possibility reshapes strategies for interpreting cosmic‑ray anisotropies measured by detectors on balloons, satellites, and Arctic ice.



HAWC continues to monitor V4641 Sagittarii, looking for day‑to‑day changes that would tie gamma‑ray flashes to radio flares seen by interferometers. 



Upcoming instruments like the <a href="https://www.ctao.org/" target="_blank" rel="noreferrer noopener">Cherenkov Telescope Array</a> will sharpen images to arc‑minute scales and hunt for corresponding neutrinos that would clinch the hadronic scenario.



The findings also motivate renewed optical vigilance, since brightening episodes could signal fresh accretion spurts that reset jet conditions.



The study is published in <a href="https://www.nature.com/articles/s41586-024-07995-9" target="_blank" rel="noreferrer noopener">Nature</a>.



-----



Like what you read?<a href="https://www.earth.com/subscribe/"> Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on<a href="https://www.earth.com/earthsnap/"> EarthSnap</a>, a free app brought to you by<a href="https://www.earth.com/author/eralls/"> Eric Ralls</a> and Earth.com.



-----

Binary star system found in the Milky Way is the new cosmic ray monster

A pair of objects 20,000 light‑years away has just broken the...

When Brian Menounos stepped onto British Columbia’s Haig Glacier last summer, the ice under his crampons felt thinner than ever.



“Over the last four years, <a href="https://www.earth.com/news/melting-glaciers-are-reshaping-landscapes-and-national-borders-around-the-world/">glaciers</a> lost twice as much ice compared to the previous decade,” he later warned. “Glacial melt is just falling off a cliff.”



A new study pieces together twenty-plus years of satellite images, laser surveys, and boots-on-ice measurements from the Rockies, Cascades, and Swiss Alps.



The verdict: glaciers in western Canada, the contiguous United States, and Switzerland have already surrendered roughly 12 percent of their total volume since 2001 - and the pace is accelerating.



<h2 class="wp-block-heading" id="h-scientists-mapped-glacier-melt">Scientists mapped glacier melt</h2>



Menounos, a <a href="https://www.unbc.ca/">University of Northern British Columbia</a> professor and chief scientist at the <a href="https://hakai.org/">Hakai Institute</a>, led an international crew that surveyed three benchmark glaciers in western Canada, four in the U.S. Pacific Northwest, and twenty in Switzerland.



These ice structures do more than decorate postcards. They are summer water towers for farms, rivers, and hydropower; they draw hikers and skiers by the millions; and they even steady mountain slopes by gluing rock walls together.



The team combined high-resolution laser altimetry from aircraft, on-site stake readings, and thousands of satellite scenes.



Those overlapping snapshots told a consistent story: from 2021 through 2024, the monitored glaciers shed as much ice as they had during the entire previous ten years. In sheer water volume, the loss is equivalent to draining huge alpine <a href="https://www.earth.com/news/water-reservoirs-are-shrinking-and-becoming-less-reliable/">reservoirs</a> within a few melt seasons.



<h2 class="wp-block-heading" id="h-dust-and-fire-darken-glaciers">Dust and fire darken glaciers</h2>



Why did melting suddenly roar ahead? Two culprits stand out. The first is heat. Early-season <a href="https://www.earth.com/news/deadly-heat-waves-in-europe-can-be-predicted-by-melting-sea-ice/">heat waves</a> have flipped the melt switch weeks ahead of schedule, scrubbing away winter snow that normally reflects sunlight and protects the ice below.



Switzerland’s record-hot summer of 2022 and western Canada’s scorching spring of 2023 gave the glaciers no time to recover. As Menounos put it, “2023 was the year of record, no question.”



The second culprit is surface darkening. Pure snow is brilliant white, bouncing most sunlight back to space. But when windblown dust or <a href="https://www.earth.com/news/climate-change-is-making-wildfire-smoke-more-deadly/">wildfire</a> soot coats the surface, that reflectivity - scientists call it albedo - plummets, and the ice soaks up heat like a blacktop road.



In the Alps, <a href="https://www.earth.com/news/saharan-dust-crosses-the-atlantic-a-journey-seen-from-space/">Saharan dust storms</a> tinted the snow a dull ocher. Across North America, smoke from unprecedented wildfire seasons peppered the ice with black carbon. 



At Haig Glacier, the researchers estimate that darkening by soot accounted for nearly forty percent of the melt between 2022 and 2023.



<h2 class="wp-block-heading" id="h-a-blind-spot-in-climate-projections">A blind spot in climate projections</h2>



These albedo changes aren’t just cosmetic. They crank up melt rates beyond what temperature alone would dictate, yet most global glacier models still ignore the effect. Menounos believes that oversight is dangerous.



“If we’re thinking, Well, we have 50 years before the glaciers are gone, it could actually be 30,” he said. “So we really need better models going forward.”



Meanwhile, wildfire activity is poised to intensify under continued warming, sending ever more carbon-rich ash onto the shrinking ice. 



That feedback loop - hotter summers, bigger fires, darker glaciers, faster melt - suggests that standard forecasts may be too optimistic about how long mid-latitude ice will survive.



<h2 class="wp-block-heading" id="h-melting-glaciers-reshape-landscapes">Melting glaciers reshape landscapes</h2>



Glaciers in Alaska or Greenland dominate sea-level discussions, but the mountain ice in this study plays a different yet critical role.



During late summer droughts, meltwater keeps rivers flowing, cools <a href="https://www.earth.com/news/many-young-salmon-break-the-typical-migration-rules-boosting-survival-chances/">salmon</a> habitat, and refills reservoirs that power cities from Seattle to Bern. 



As the ice retreats, that dependable trickle will shrink, leaving farms, hydro dams, and ecosystems exposed to deeper dry spells.



A faster melt-out invites hazards, too. When valley glaciers thin, steep rock faces lose their frozen mortar and can tumble into valley bottoms. Newly formed glacial lakes, dammed only by loose rubble, can burst in sudden floods.



The catastrophic debris flow in British Columbia’s Elliot Creek in 2020, linked to rapid deglaciation, hints at risks that could multiply as ice fronts march uphill.



<h2 class="wp-block-heading" id="h-a-landscape-without-long-term-ice">A landscape without long-term ice</h2>



All of this raises a sobering question: how do communities adapt to a future with little or no perennial ice? Menounos argues that water planners, engineers, and tourism operators need to start drawing up new playbooks.



“Society needs to be asking what are the implications of ice loss going forward,” he said. “We need to start preparing for a time when glaciers are gone from western Canada and the United States.”



That might mean revisiting water-sharing agreements, fortifying infrastructure against outburst <a href="https://www.earth.com/news/flood-fatalities-experts-reveal-the-hidden-health-impacts/">floods</a>, or reinventing alpine tourism for snow-starved summers.



<h2 class="wp-block-heading" id="h-a-warning-etched-in-melting-glaciers">A warning etched in melting glaciers</h2>



The study’s most unsettling lesson is how quickly feedbacks can compress geologic timescales into human lifetimes. A hotter atmosphere begets larger fires; those fires darken glaciers; dark ice melts at turbo speed, exposing yet more dark ice. Each loop feeds the next.



If policymakers needed a tangible example of climate acceleration, these rapidly vanishing ice fields provide it. 



The sight of a glacier “falling off a cliff” is no longer a metaphor. It is a literal snapshot of Earth’s changing face - one that may disappear from living memory far sooner than we ever imagined.



The study is published in the journal <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL115235">Geophysical Research Letters</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Glaciers from the Rockies to the Alps are melting much faster than expected

When Brian Menounos stepped onto British Columbia’s Haig Glacier last...

Child-directed speech, also known as “baby talk,” plays a vital role in human development. Around the world, caregivers use a distinct vocal style to talk to infants. 



These modified speech patterns help young minds absorb vocabulary and structure. But how did this behavior originate? Could it have evolved from our primate ancestors?



A recent study led by researchers from the <a href="https://www.uzh.ch/en.html" target="_blank" rel="noreferrer noopener">University of Zurich</a>, <a href="https://www.unine.ch" target="_blank" rel="noreferrer noopener">University of Neuchâtel</a>, and collaborators across Europe and the U.S. offers new insights. 



The research, published in the journal Science Advances, explores whether great apes use infant-directed vocalizations like humans do.



<h2 class="wp-block-heading" id="h-baby-talk-in-humans-and-apes">Baby talk in humans and apes</h2>



The team observed wild populations of bonobos, chimpanzees, gorillas, and orangutans. They also included data from human infants across diverse cultures: Shipibo-Konibo, Qaqet, Chintang, and Tuatschin.



To quantify communication, they analyzed vocal behavior during two-minute intervals. They categorized each instance as infant-directed, surrounding, or general vocal activity. 



They followed immature individuals closely, noting all relevant sounds from nearby group members.



<h2 class="wp-block-heading" id="h-humans-use-baby-talk-way-more">Humans use baby talk way more</h2>



These results highlight how unique human caregiving behavior is compared to that of our closest relatives. Human <a href="https://www.earth.com/news/how-do-infants-connect-with-the-world-it-all-starts-with-the-feet/">infants</a> are surrounded by vocal input that is not only frequent but also specifically tailored to them. This level of attention likely helps them learn language faster and more efficiently.



Even when focusing only on what mothers said, humans stood out. Mothers spoke directly to their babies far more than ape mothers did. In fact, the difference between human and bonobo mothers was over 400-fold.



Most of the speech around human infants was directed at them. In contrast, great apes showed almost no such targeted communication. 



This suggests that humans may have evolved a special way of teaching language that relies heavily on speaking directly to infants.



<h2 class="wp-block-heading" id="h-not-just-direct-speech">Not just direct speech</h2>



Surrounding speech refers to vocalizations that infants can hear but are not directly addressed to them. This type of input was fairly consistent across humans, <a href="https://www.earth.com/news/chimpanzees-select-the-best-materials-for-termite-fishing/">chimpanzees</a>, and bonobos. 



These species likely live in more socially active environments, where infants overhear conversations or calls.



Orangutans, however, received much less surrounding speech. This fits their more solitary lifestyle, where fewer individuals are nearby to produce vocalizations.



Because infant-directed speech is rare among apes, they may depend more on what they hear in the background. This ambient input could help them learn communication patterns, even without being directly taught.



<h2 class="wp-block-heading" id="h-baby-talk-helped-humans-evolve">Baby talk helped humans evolve</h2>



The data suggest a sharp evolutionary shift. “Our findings suggest that the tendency to direct vocalizations at infants... has been massively expanded in the human lineage,” the authors wrote.



One possible driver is the need to transmit learned communication. Unlike apes, human language is highly flexible and requires teaching. Infant-directed speech helps children grasp words, tone, and context more easily.



Interestingly, gestures may play a more prominent role in great apes. Repetitive <a href="https://www.earth.com/news/wild-bird-uses-wing-gestures-to-politely-say-after-you/">gestures</a> in apes mirror some features of human baby talk. These findings hint that vocal and gestural teaching modes may have evolved in parallel.



<h2 class="wp-block-heading" id="h-are-humans-alone-not-quite">Are humans alone? Not quite</h2>



Other species also engage in infant-directed communication. Dolphins change pitch when around calves. Bats alter calls to suit pups. Cats and monkeys use specific sounds to call or calm infants.



However, these communications likely serve different functions, like identification or retrieval. Only in humans do these vocal patterns appear tightly linked to complex language learning.



<h2 class="wp-block-heading" id="h-studying-apes-to-understand-ourselves">Studying apes to understand ourselves</h2>



The study opens up new paths. The researchers propose exploring who produces surrounding speech in ape societies, siblings, mothers, or others, and whether that affects learning.



Additionally, they call for deeper study of ape gestures directed at infants. “The gestural modality might represent an additional fruitful avenue for future work."



This research provides strong support that child-directed speech may have evolved to support <a href="https://www.earth.com/news/babies-can-naturally-learn-multiple-languages-from-birth/">language learning</a>. Our ancestors likely began with ambient communication, then shifted toward more intentional, tailored speech as language grew more complex.



By comparing the way species talk, or don’t talk, to their young, we gain a clearer view of what makes human language so powerful and so unique.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/sciadv.adt7718" target="_blank" rel="noreferrer noopener">Science Advances</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Baby talk may explain what sets humans apart from apes

Child-directed speech, also known as “baby talk,” plays a vital...

Soft corals have been part of coral reef ecosystems for millions of years, yet scientists are only beginning to grasp how many kinds exist and where they live. Even after decades of research, large parts of reef life remain a mystery.



“A majority of the things that are out there on coral reefs are simply unknown to us or haven’t been formally described or named,” said Catherine McFadden, a professor of life sciences at <a href="https://www.hmc.edu/">Harvey Mudd College</a>.



McFadden leads a new study with an international team from Harvey Mudd College and the Florida Museum of Natural History.



It’s the largest-ever genetic survey of soft corals, built from more than 4,400 museum specimens collected over two decades. And it has fundamentally changed how scientists understand coral diversity and where it occurs.



<h2 class="wp-block-heading" id="h-new-center-of-coral-life">New center of coral life</h2>



<a href="https://www.earth.com/news/coral-reefs-may-be-more-resilient-than-we-thought/">Coral reefs</a> are typically richest in species in the central Indo-Pacific. That’s the Coral Triangle - Indonesia, the Philippines, Papua New Guinea, and surrounding islands - a region known for its warm, shallow waters and unmatched biodiversity.



But this new study found that soft corals break that rule. They don’t have just one center of diversity - they have two.



The first overlaps with the Coral Triangle, as expected. But the second hotspot? It’s thousands of miles west, along the coasts of <a href="https://www.earth.com/news/madagascar-extinctions-linked-to-human-expansion-1000-years-ago/">Madagascar</a> and Southeast Africa. Here, soft corals are just as diverse - maybe more so - than in the better-known Indo-Pacific. That’s not the case for their harder cousins.



Stony corals, which build reefs from calcium carbonate, are less common and less varied in East Africa. Soft corals are different. And this difference may hold clues to how coral ecosystems evolved, and how they’ll survive in the future.



<h2 class="wp-block-heading" id="h-ancient-coral-branches-split">Ancient coral branches split</h2>



Stony and soft corals both evolved from the same ancient group: Anthozoa. This group originated around 771 million years ago. Shortly after, it split into two major branches - Hexacorallia and Octocorallia. The former gave us stony corals. The latter gave us soft corals.



Their differences go far beyond skeletons. <a href="https://www.earth.com/news/study-reveals-reproductive-secrets-of-stony-corals/">Stony corals</a> have hard structures that make them easier to identify by shape. Soft corals lack these features, making them notoriously hard to tell apart.



“It is really challenging to identify them in the field. It’s a colony of very similar polyps, often with similar growth forms, and that’s about it,” said Gustav Paulay, co-author of the study and curator at the Florida Museum of Natural History.



<h2 class="wp-block-heading" id="h-looks-deceive-in-soft-corals">Looks deceive in soft corals</h2>



Soft corals use water pressure to keep their shape and rely on tiny calcium structures called sclerites for support. These structures are beautiful under a microscope, but unreliable when it comes to classification.



“We call them snowflakes because every single sclerite is different,” McFadden said. “They have intricate forms. They’re hard to quantify. And we don’t have a good understanding of what makes them different.”



Once scientists began using DNA to study soft corals, it exposed major gaps in how these species had been classified. Visual identification alone had masked both hidden diversity and false differences.



“There are many cases where people thought there was a widespread species, but when we do the genetic work, it turns out it’s six or eight different things that in some cases aren’t even closely related to each other,” McFadden said. 



“We have the opposite problem as well where corals take a different growth form in some environments, but genetically, we’re not finding any differences between them.”



<h2 class="wp-block-heading" id="h-a-constant-struggle-on-the-reef">A constant struggle on the reef</h2>



Despite their different lineages, soft and stony corals often compete for the same space. The battle can get nasty.



Soft corals release toxic chemicals to keep others at bay. Stony corals strike back with stinging tentacles or even smother competitors with digestive tissue. Coral reefs may look peaceful, but turf wars are constant.



And yet, both types of coral have adapted to reef life in their own ways—until you get to the western Indian Ocean, where soft corals seem to be pulling ahead.



<h2 class="wp-block-heading" id="h-reefs-stranded-by-tectonics">Reefs stranded by tectonics</h2>



This unexpected diversity in the Indian Ocean has roots in ancient geography. Twenty million years ago, a vast seaway called the Tethys Sea connected oceans from Asia to the Atlantic. It was full of coral reefs -until continental drift closed it off.



As Africa and Europe moved together, coral systems were squeezed and isolated. Some were cut off entirely. 



“As the Indonesian archipelago formed, reefs ended up colonizing that, and the diversity shifted there,” Paulay said.



The reefs of Madagascar and East Africa are remnants of what once stretched across a much wider region. This isolation might help explain their unique mix of species today.



<h2 class="wp-block-heading" id="h-why-soft-corals-don-t-travel-well">Why soft corals don’t travel well</h2>



One big reason soft corals have two diversity centers comes down to how they reproduce.



Corals reproduce both asexually and sexually. In sexual <a href="https://www.earth.com/news/how-do-corals-have-sex-new-secrets-of-spawning-revealed/">reproduction</a>, some corals “broadcast” their eggs and sperm into the ocean. Others, called brooders, keep fertilized larvae inside until they’re ready to release them.



Broadcasting allows coral larvae to travel far - sometimes hundreds of miles. Brooding larvae, on the other hand, tend to sink near their parents. They don’t go far, and that limits their range.



Soft corals, especially brooders, aren’t good travelers. This helps explain why they’re largely missing from places like the tropical Atlantic and parts of the Pacific. It also explains why so many are unique to a single region.



The study found that endemic species - those found only in one area - were most common in the western Indian Ocean. And most of those were brooders.



<h2 class="wp-block-heading" id="h-warming-threatens-rare-corals">Warming threatens rare corals</h2>



Endemic species are vulnerable. If their habitat disappears, they have nowhere else to go. The soft corals of Madagascar and East Africa face serious threats from warming oceans, overfishing, and pollution.



“When <a href="https://www.earth.com/news/coral-bleaching-has-reached-catastrophic-levels-on-the-great-barrier-reef/">bleaching</a> occurs with stony corals, they can often recover, depending on the severity and length of time they bleach,” McFadden said. “That’s not been documented with soft corals. They bleach, and they’re gone.”



If soft corals are more sensitive to bleaching - and more geographically restricted - the risks are compounded. But this also creates opportunity. Knowing where biodiversity is concentrated helps scientists know where to look for new species and where conservation efforts can do the most good.



“If you look at the number of studies that have actually identified species reliably across broad geographic ranges, it’s really focused on just maybe a half dozen groups of organisms,” McFadden said.



Most of those studies target species that humans use or consume. Soft corals don’t fall into that category. But they matter - ecologically, biologically, and as part of the reefs that support life in the ocean.



This new research gives us a clearer picture of coral diversity. More importantly, it reminds us how much we still don’t know - and how much there is left to protect.



The full study was published in the journal <a href="https://www.nature.com/articles/s41598-025-98790-7">Scientific Reports</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Scientists discover hidden hotspot where soft corals are thriving

Soft corals have been part of coral reef ecosystems for...

A familiar song often pulls dormant memories into focus. Scientists have long wondered why music has such a direct line to memory.



New research reports that the feelings a <a href="https://www.earth.com/news/our-brain-doesnt-just-hear-music-it-becomes-the-rhythm/">listener</a> experiences while the song plays decide which parts of the memory resurface.



The study was led by Kayla Clark, a cognitive neuroscientist at <a href="https://www.rice.edu/">Rice University</a>, and Dr. Stephanie Leal of UCLA.



<h2 class="wp-block-heading" id="h-music-emotion-and-memory">Music, emotion, and memory</h2>



The team focused on <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7381437/" target="_blank" rel="noreferrer noopener">emotional arousal</a>, the measurable surge of attention and bodily activity that follows a strong feeling. This surge controls hormone release linked to memory storage.



Modern brain‑imaging confirms the century‑old <a href="https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613%2824%2900078-0" target="_blank" rel="noreferrer noopener">Yerkes–Dodson law</a>, which shows that performance <a href="https://www.earth.com/news/some-people-are-born-to-enjoy-music-more-than-others/">peaks</a> at moderate arousal and drops at both extremes.



Prior <a href="https://pubmed.ncbi.nlm.nih.gov/19421427/" target="_blank" rel="noreferrer noopener">studies</a> reveal that high‑arousal scenes strengthen memory for the gist, while low arousal helps people keep track of fine details. 



Large reviews further show that regular music therapy can sharpen cognition in people with dementia, an effect stronger than many non‑pharmacological programs.



<h2 class="wp-block-heading" id="h-soundtracks-influence-memory">Soundtracks influence memory</h2>



Clark and Leal recruited 130 young adults who first saw images of everyday objects. 



Thirty minutes later, during the vulnerable consolidation window, participants completed questionnaires while hearing happy, sad, familiar, or unfamiliar classical pieces, neutral sounds, or silence.



After the ten‑minute listening period everyone faced a memory test that asked them to tag pictures as “old,” “new,” or “similar,” a task that separates general recall from precise <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC3183227/" target="_blank" rel="noreferrer noopener">pattern separation</a>.



<h2 class="wp-block-heading" id="h-more-emotion-less-precision">More emotion, less precision</h2>



“The more emotional that people became from the <a href="https://www.earth.com/news/nostalgic-songs-light-up-your-brain-and-get-you-moving/">music</a>, the more they remembered the gist of a previous event. But people who had more moderate emotional responses to music remembered more details of previous events,” explained Clark. 



Individual reactions diverged even though the playlists were identical. Some listeners showed big spikes in arousal, others a moderate lift, and a third group actually calmed down.



Statistical clustering confirmed her words. Gist memory improved when arousal shot up or down, while the sharp discrimination of look‑alike images peaked only in the moderate group. 



Listeners who heard neutral sounds or silence did not show the same flip‑flop pattern, suggesting that music engages memory circuits differently from generic noise.



<h2 class="wp-block-heading" id="h-what-it-means-for-daily-life">What it means for daily life</h2>



If you need to recall the outline of a lecture, you may benefit from energizing tracks that push arousal to the top of the curve. 



By contrast, writers, detectives, and students who must store minute specifics might choose calmer pieces that create a gentle emotional bump rather than a rush.



Because every brain gauges arousal differently, the most helpful <a href="https://www.earth.com/news/music-has-the-power-to-change-the-mood-of-our-memories/">playlist</a> will be personal. Smartphone sensors that read heart rate or skin conductance could someday adapt background music in real time, nudging each listener toward an individual sweet spot.



<h2 class="wp-block-heading" id="h-match-music-to-memory">Match music to memory</h2>



Several brain regions help explain why music influences different types of memory. The hippocampus supports pattern separation, the ability to tell similar experiences apart, while the amygdala boosts memory for emotionally charged events.



Music also activates the nucleus accumbens and <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9164627/" target="_blank" rel="noreferrer noopener">ventral tegmental area</a>, key players in the brain’s reward system that release dopamine during pleasurable moments. 



This neural cocktail may shift memory storage pathways depending on emotional intensity.



<h2 class="wp-block-heading" id="h-playlists-powered-by-biosignals">Playlists powered by biosignals</h2>



Tech developers are beginning to explore how biometric feedback could guide music curation. Wearables that track <a href="https://www.health.harvard.edu/blog/heart-rate-variability-new-way-track-well-2017112212789" target="_blank" rel="noreferrer noopener">heart rate variability</a> or skin conductance might detect emotional arousal and adjust playlists to support focus or memory.



Some apps already use mood tagging or AI-driven personalization, but most lack real-time physiological input. 



Pairing arousal monitoring with tailored soundtracks could lead to smart systems that enhance memory on demand.



<h2 class="wp-block-heading" id="h-memory-response-to-music-is-personal">Memory response to music is personal</h2>



Music that triggers strong emotional responses in one person might leave another unmoved. 



Factors like cultural background, personal experiences, and past associations shape how a listener reacts to a particular <a href="https://www.earth.com/news/higher-sound-quality-music/">song</a>.



This helps explain why familiar music didn't always cause the biggest change in arousal. Even songs rated as highly emotional overall had mixed effects across participants, underlining the need for personalized interventions.



<h2 class="wp-block-heading" id="h-toward-tailored-dementia-care">Toward tailored dementia care</h2>



Memory loss in Alzheimer’s disease often spares broad stories while erasing specifics, the very trade‑off the study maps. 



Personalized playlists might counter that imbalance by steering arousal into the moderate range that supports detail retention.



A 2024 <a href="https://alzres.biomedcentral.com/articles/10.1186/s13195-023-01214-9" target="_blank" rel="noreferrer noopener">meta‑analysis</a> of randomized trials reported that music interventions improved global cognition in nursing‑home residents without adding stress, reinforcing the promise of targeted musical medicine.



Future work will need to test older adults, diverse musical genres, and longer follow‑ups, but the current findings offer a practical guide: match the music to the memory goal rather than assuming more volume or excitement is always better.



The study is published in the <a href="https://www.jneurosci.org/content/early/2025/06/12/JNEUROSCI.0158-25.2025" target="_blank" rel="noreferrer noopener">Journal of Neuroscience</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Listening to music can change how we recall memories

A familiar song often pulls dormant memories into focus. Scientists...

Can lichen survive on planets blasted with far more solar radiation than Earth? It’s a question that cuts to the heart of whether life could exist beyond our planet. Scientists have been looking to the skies for answers - and now, a new study offers one. 



Researchers from the Desert Research Institute (<a href="https://www.dri.edu/">DRI</a>) and the University of Nevada, Reno (<a href="https://www.unr.edu/?utm_source=google&amp;utm_medium=organic&amp;utm_campaign=knowledge-panel">UNR</a>) have found that a common lichen growing in the Mojave Desert can survive levels of ultraviolet radiation previously thought to be lethal.



The study shows that this humble desert lichen might hold the key to understanding how life could endure in extreme environments on other worlds.



<h2 class="wp-block-heading" id="h-why-is-the-lichen-black">Why is the lichen black?</h2>



The idea for the study started with something small and simple - a color.



“I was just walking in the desert and I noticed that the lichens growing there aren’t green, they’re black,” said Henry Sun, associate research professor of microbiology at DRI.



 “They are photosynthetic and contain chlorophyll, so you would think they’d be green. So I wondered, ‘What is the pigment they're wearing?’ And that pigment turned out to be the world’s best sunscreen.”



That “sunscreen” is a dark pigment on the surface of the lichen, Clavascidium lacinulatum, which lives in harsh, sun-drenched environments like the <a href="https://www.earth.com/news/burrowing-animals-in-the-mojave-desert-escape-the-heat-of-climate-change/">Mojave</a>. Despite being constantly bombarded with solar radiation, the lichen survives - and thrives.



<h2 class="wp-block-heading" id="h-exoplanets-face-uv-extremes">Exoplanets face UV extremes</h2>



Our planet’s atmosphere filters out the most dangerous form of <a href="https://www.earth.com/news/uv-radiation-played-a-role-in-earths-largest-mass-extinction/">ultraviolet radiation</a>: UVC. It's the shortest and most harmful of the UV spectrum. 



We never experience it on Earth’s surface, but many <a href="https://www.earth.com/news/exotic-worlds-tess-unveils-126-new-exoplanets/">exoplanets</a> orbit stars that emit it in high doses - especially M and F type stars.



UVC is powerful enough to sterilize hospital rooms. It breaks down DNA and prevents reproduction in even the hardiest microorganisms. 



So the idea that anything could live on a planet exposed to that kind of radiation has seemed like a long shot. That is, until now.



<h2 class="wp-block-heading" id="h-90-days-under-the-lamp">90 days under the lamp</h2>



Sun and his then-graduate student, Tejinder Singh, collected lichens from the desert near their homes in Las Vegas. They exposed the lichens to nonstop UVC radiation under lab conditions for three months - far longer than most studies of this kind.



“In order for a <a href="https://www.earth.com/news/how-microorganisms-swim-without-a-brain-and-why-it-matters/">microorganism</a> to persist on a planet, it has to last longer than a day,” Sun explained. “So, our experiment had to be long enough to be ecologically significant. We also wanted to go beyond just activity and demonstrate viability.”



When the lichen was rehydrated after the experiment, half of the algal cells were still alive. They didn’t just survive - they replicated.



<h2 class="wp-block-heading" id="h-how-the-lichen-survived">How the lichen survived</h2>



To understand the chemical shield protecting the lichen, the team worked with chemists at UNR. Together, they ran experiments that revealed a simple secret: the acids in the lichen's outer layer function like additives in plastic that prevent UV damage.



The researchers sliced the lichen open and found a dark, protective top layer - like a natural sunblock. 



Lichen is a mix of algae or cyanobacteria living in partnership with <a href="https://www.earth.com/news/fungi-can-think-and-make-smart-decisions-without-a-brain/">fungi</a>. When the algal cells were separated from the fungi and protective layer, they couldn’t take the radiation. They died in under a minute.



Sun said what surprised them most was that this protection is not even necessary for survival on Earth. Our atmosphere already blocks UVC. “The protection is a mere bonus thanks to their remarkable UVA and UVB protection,” he said.



<h2 class="wp-block-heading" id="h-even-the-air-matters">Even the air matters</h2>



Solar radiation isn’t the only threat. When UV rays interact with certain chemicals in the air - like oxygen and nitric oxide - they can trigger reactions that create reactive oxygen species. These molecules can damage cells even more.



So the team ran another test. They placed the lichen in an oxygen-free environment while continuing UVC exposure. The result: less radiation damage.



“We came to the conclusion that the lichen’s top layer - a less than millimeter thick skin, if you will - assures that all the cells below are protected from radiation,” the researchers wrote. 



“This layer acts as a photo stabilizer and even protects the cells from harmful chemical reactions caused by the radiation, including reactive oxygen.”



<h2 class="wp-block-heading" id="h-life-beyond-earth">Life beyond Earth</h2>



The takeaway? Planets that seem too hostile might still host life. Microorganisms could adapt, protect themselves, and persist - just like the black lichens in the <a href="https://www.earth.com/news/burrowing-animals-in-the-mojave-desert-escape-the-heat-of-climate-change/">Mojave Desert</a>.



“This work reveals the extraordinary tenacity of life even under the harshest conditions, a reminder that life, once sparked, strives to endure,” said Singh, who is now at NASA’s Goddard Space Flight Center. 



“In exploring these limits, we inch closer to understanding where life might be possible beyond this planet we call home.”



In short, life might not need Earth-like conditions to exist. It may just need a way to adapt - and a very good tan.



The full study was published in the journal <a href="https://www.liebertpub.com/doi/10.1089/ast.2024.0137">Astrobiology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Desert lichen may offer clues to life beyond Earth

Can lichen survive on planets blasted with far more solar...

The monarch may steal the spotlight, yet an ongoing crisis is affecting nearly every butterfly <a href="https://www.earth.com/news/butterflies-can-adapt-quickly-but-evolution-has-its-limits/">species</a> in the lower 48. Between 2000 and 2020, total abundance fell by 22 percent, according to the largest survey ever assembled.



That national <a href="https://naba.org/wp-content/uploads/2025/03/Rapid-butterfly-declines-across-the-United-States-during-the-21st-century_Science_03072025.pdf" target="_blank" rel="noreferrer noopener">dip</a> works out to 1.3 percent each year, a slow‑motion slide that rarely makes headlines but never takes a day off.



<h2 class="wp-block-heading" id="h-butterfly-species-decline-and-habitat-loss">Butterfly species decline and habitat loss</h2>



Roughly a third of the 342 <a href="https://www.earth.com/news/butterfly-migration-habits-are-not-determined-by-their-dna/">species</a> with solid data are shrinking fast, and 107 have already slipped by more than half of their former counts. 



Habitat carved into parking lots, hotter summers driven by climate change, and heavy use of pesticides each gnaw at different life stages, yet together they form a three‑pronged squeeze.



Even the unglamorous caterpillar matters here: without the right host leaves, no egg survives, no adult emerges, and no pollination happens. 



Cheryl Schultz of <a href="https://wsu.edu/">Washington State University</a> helped write the new recovery roadmap. She says the clock is ticking for the insects she has studied for three decades.



<h2 class="wp-block-heading" id="h-long-term-drop-in-butterfly-numbers">Long-term drop in butterfly numbers</h2>



The Science team pulled 12.6 million field observations from 76,000 surveys, then wrangled conflicting protocols into one set of trend lines.



Patterns varied by region, but the Southwest stood out as hardest hit, while the Pacific Northwest held steady only because one irruptive tortoiseshell species briefly boomed.



The authors stress that <a href="https://www.earth.com/news/butterfly-hovering-technique-could-revolutionize-drone-design/">butterflies</a> act as living barometers: when they vanish, so do many less‑monitored insects doing similar ecological work. 



Losing butterflies also removes food for birds and other wildlife that depend on soft‑bodied prey each spring.



<h2 class="wp-block-heading" id="h-cleaning-data-to-track-real-trends">Cleaning data to track real trends</h2>



Tracking butterfly abundance across hundreds of species isn't easy. Observations often come from community science platforms like iNaturalist, where users sometimes upload misidentified species or report tropical butterflies from butterfly houses as wild sightings.



To clean the data, researchers used <a href="https://txtav.com/en/range-map" target="_blank" rel="noreferrer noopener">range maps</a> to flag out-of-place records and exclude bad data from their models. 



Eliza Grames, an assistant professor at <a href="https://www.binghamton.edu/">Binghamton University</a>, said this step was key to making sure the trends reflected actual changes in nature rather than errors in reporting. Professor Grames specializes in using <a href="https://libguides.uta.edu/quantitative_and_qualitative_research/quant" target="_blank" rel="noreferrer noopener">quantitative methods</a>, evidence synthesis, and long-term datasets to understand how climate, habitat loss, and species interactions are affecting biodiversity. 



Her work focuses on combining scattered data sources like historical surveys and citizen science to track insect declines and guide effective conservation.



<h2 class="wp-block-heading" id="h-restoring-habitats-for-butterfly-species">Restoring habitats for butterfly species</h2>



Scott Black is the director of the <a href="https://www.xerces.org/">Xerces Society</a> and a co‑author of the recovery roadmap.



"Butterflies need host plants on which to lay eggs, wildflowers on which to feed, a refuge from pesticides, and sites to overwinter. There is hope for these animals if we focus on providing habitat for butterflies across all landscapes,” said Black. 



Providing season‑long bloom is key, and <a href="https://xerces.org/pollinator-conservation/habitat-restoration/management" target="_blank" rel="noreferrer noopener">Xerces</a> maintains region‑specific plant lists that match native flowers with local nectar feeders.



Land managers are urged to skip blanket spraying and instead spot‑treat weeds, mow outside bloom windows, and leave leaf litter for overwintering adults or chrysalids. 



Protecting habitat also buffers butterflies against flash droughts and early frosts that are becoming more common as weather swings widen.



<h2 class="wp-block-heading" id="h-green-spaces-support-butterfly-species">Green spaces support butterfly species</h2>



The recovery roadmap emphasizes that conservation must happen everywhere, not just in protected wilderness. Even small green spaces can play a huge role when stitched together across cities, suburbs, and farms.



Pollinator corridors, like roadside flower strips or native plant buffers on farmland, let butterflies travel, feed, and lay eggs without interruption. 



When neighbors and land managers coordinate efforts, isolated patches of habitat can become a functioning network that supports entire species.



<h2 class="wp-block-heading" id="h-butterfly-species-and-cotton-yields">Butterfly species and cotton yields</h2>



Economics add weight to conservation: research in <a href="https://cns.utexas.edu/news/research/supporting-pollinators-could-have-big-payoff-texas-cotton-farmers" target="_blank" rel="noreferrer noopener">Texas</a> shows that <a href="https://www.earth.com/news/national-learn-about-butterflies-day-an-enchanting-world-awaits/">butterflies</a> translate into about $100 million in annual pollination value for cotton alone.



When rows of nectar plants bordered the fields, cotton set more bolls, and farmers noticed a boost in yield without another drop of chemical inputs.



<h2 class="wp-block-heading" id="h-how-to-help-butterfly-species">How to help butterfly species</h2>



Homeowners can swap a slice of turf for milkweed, asters, and goldenrod. City planners can seed bloom strips along bike paths and medians instead of short mowed grass.



Rural roadsides double as corridors when mowing heights stay above six inches and herbicide use is limited to targeted patches, a change that costs little but scales quickly.



Even small pollinator islands in solar arrays or utility rights‑of‑way create stepping‑stones that let populations recolonize after drought or fire.



Success stories already exist. The Fender’s blue butterfly, once presumed lost, bounced back enough for the <a href="https://oregoncapitalchronicle.com/2023/10/16/pink-wildflower-in-oregon-and-southwest-washington-removed-from-federal-protection/" target="_blank" rel="noreferrer noopener">U.S. Fish &amp; Wildlife Service</a> to reclassify it from endangered to threatened in 2023.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/science.adp4671" target="_blank" rel="noreferrer noopener">Science</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Butterfly species are declining fast across the United States

The monarch may steal the spotlight, yet an ongoing crisis...

Typhoid fever, which was once knocked down by simple pills, is standing up again. The bacterium Salmonella typhi now shows resistance to almost every antibiotic that doctors throw at it.



“The speed at which highly‑resistant strains of <a href="https://www.sciencedirect.com/science/article/pii/S2666524722000933" target="_blank" rel="noreferrer noopener">S. typhi</a> have emerged and spread in recent years is a real cause for concern,” said Jason Andrews of <a href="https://www.stanford.edu/" target="_blank" rel="noreferrer noopener">Stanford University</a><a href="https://stacks.cdc.gov/view/cdc/175241/cdc_175241_DS1.pdf?utm_source=chatgpt.com"> </a>



<h2 class="wp-block-heading" id="h-how-typhoid-resistance-happens">How typhoid resistance happens</h2>



Modern <a href="https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases/typhoid-and-paratyphoid-fever.html" target="_blank" rel="noreferrer noopener">treatment</a> depends on antibiotics killing the typhoid bacterium faster than it mutates. That race is tilting toward the microbe because antimicrobial resistance grows every time a course of drugs is cut short or the wrong medicine is prescribed.



Genomic work on 3,489 isolates from India, Pakistan, Nepal, and Bangladesh shows resistant typhoid strains replacing susceptible ones in only a few years. 



Some of those isolates carry three mutations in the DNA‑gyrase genes that raise the ciprofloxacin dose needed a thousand‑fold, and remove a key outpatient option.



Third‑generation cephalosporins followed ciprofloxacin onto the front line in the early 2000s. 



But now, a 2025 survey in Ahmedabad, India, has uncovered a cluster showing resistance to ceftriaxone, ampicillin, ciprofloxacin, and <a href="https://www.ncbi.nlm.nih.gov/books/NBK513232/" target="_blank" rel="noreferrer noopener">trimethoprim‑sulfamethoxazole</a>. This marks “the largest hotspot of ceftriaxone‑resistant typhoid identified to date.”



<h2 class="wp-block-heading" id="h-a-shrinking-menu-of-antibiotics">A shrinking menu of antibiotics</h2>



Only azithromycin still works reliably by mouth. Laboratory monitoring in Pakistan found minimum inhibitory concentrations creeping upward, and a U.S. bulletin this year recorded the first two homegrown azithromycin‑resistant cases.



Typhoid resistance there comes from a single change in the <a href="https://www.nature.com/articles/nature13205" target="_blank" rel="noreferrer noopener">AcrB efflux pump</a>, which ejects the drug before it can act. That mutation has appeared at least seven separate times since 2013 according to whole‑genome timelines.



When azithromycin finally fails, intravenous carbapenems will be the fallback. Those drugs are expensive and scarce in many endemic regions, making hospitalization the only path to survival for many patients.



<h2 class="wp-block-heading" id="h-typhoid-vaccines-on-deck">Typhoid vaccines on deck</h2>



Three typhoid vaccines are licensed worldwide, and the conjugate vaccine works in babies as young as six months. 



The <a href="https://www.who.int/news-room/fact-sheets/detail/typhoid" target="_blank" rel="noreferrer noopener">WHO</a> “recommends introduction of typhoid conjugate vaccine in countries with a high burden of the disease,” a policy that is meant to cut cases before resistance spreads any wider.



Pakistan added the shot to its routine schedule in 2019 as the first nation to do so. Early surveillance suggests fewer childhood cases in vaccinated districts, which will buy time for antibiotic pipelines to catch up.



Economic models from India project that urban vaccination could prevent more than one‑third of typhoid deaths over the next decade. 



That payoff grows if resistant strains keep rising, because every averted infection also avoids an expensive hospital stay.



<h2 class="wp-block-heading" id="h-fueling-antibiotic-resistance">Fueling antibiotic resistance</h2>



The same flights that move people, move <a href="https://www.earth.com/news/why-disinfectants-kill-99-9-of-germs-not-100/">pathogens</a>. Genomic “family trees” trace at least 59 intercontinental jumps of resistant S. typhi since 1990, with most departures being from South Asia. 



Once a strain lands, local water and sanitation gaps let it settle in. East Africa and Southeast Asia now report lineages that match South Asian ancestors, base pair for base pair.



Even countries with safe water see spillover. The CDC recorded about 450 culture‑confirmed typhoid cases in the United States in 2019, nearly all linked to recent travel. 



Doctors there face a puzzle because routine empiric therapy may not cover the imported H58 lineage, which often resists five or more drugs. Rapid susceptibility testing, still unavailable in many clinics, is becoming a must‑have.



<h2 class="wp-block-heading" id="h-typhoid-resistance-surveillance">Typhoid resistance surveillance</h2>



Without continuous <a href="https://www.cdc.gov/traveler-genomic-surveillance/about/index.html" target="_blank" rel="noreferrer noopener">genomic surveillance</a>, new resistant strains can spread silently across borders before health systems react. 



A 2022 study tracked nearly 8,000 S. typhi genomes to map origins and movements, but this kind of data is still rare in low‑resource settings.



<a href="https://www.earth.com/news/new-study-shows-that-dairy-milk-cheese-consumption-improves-gut-biodiversity-health/">Health</a> policy must keep pace with these shifts. Countries with rising resistance should not wait for full outbreaks before introducing vaccines or adjusting treatment protocols. 



Rapid response depends on accurate, real‑time data and public health systems empowered to act on it.



<h2 class="wp-block-heading" id="h-what-clinicians-can-do">What clinicians can do</h2>



Full 10 to 14 day <a href="https://jptcp.com/index.php/jptcp/article/download/9663/9003/20004" target="_blank" rel="noreferrer noopener">azithromycin courses</a> remain effective in most places, but follow‑up cultures are critical. Skipping the post‑treatment check risks silent carriers reseeding communities.



Where laboratories can measure ceftriaxone MICs, a rising trend should trigger public health alerts. Combination therapy, for example azithromycin plus meropenem in severe disease, can slow further resistance but raises costs.



Doctors also need to report every instance of typhoid resistance and <a href="https://www.earth.com/news/secrets-of-cancer-cell-death-may-transform-treatment/">treatment</a> failure. Aggregated data guide updates to national formularies faster than peer‑reviewed studies can.



<h2 class="wp-block-heading" id="h-big-gains-from-basic-safety-measures">Big gains from basic safety measures </h2>



Researchers are trialing new <a href="https://www.ncbi.nlm.nih.gov/books/NBK557592/" target="_blank" rel="noreferrer noopener">oral β‑lactamase inhibitors</a> that restore activity to cheap penicillins, but results are years away. Phage therapy and resistant‑bacteria “decoys” are on bench tops, and are promising but unproven.



Meanwhile, the biggest gains come from the basics. Safe water, sewer infrastructure, and reliable refrigeration cut typhoid risk more than any pill ever will.



Each dollar spent there pays back across multiple diseases, not just typhoid. That return on investment remains the strongest argument for governments that are watching <a href="https://www.earth.com/news/new-tool-detects-changes-in-gut-health-to-help-prevent-disease/">health</a> budgets tighten.



The study is published in the journal <a href="https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(22)00093-3/fulltext" target="_blank" rel="noreferrer noopener">The Lancet Microbe</a>.



-----



Like what you read?<a href="https://www.earth.com/subscribe/"> Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on<a href="https://www.earth.com/earthsnap/"> EarthSnap</a>, a free app brought to you by<a href="https://www.earth.com/author/eralls/"> Eric Ralls</a> and Earth.com.



-----

Typhoid fever is becoming immune to almost all antibiotics, causing great concern

Typhoid fever, which was once knocked down by simple pills,...

Relocating elephants to fresh herds can boost genetics and social health - but what if the animals can’t “talk” to their new hosts? 



Field biologists have discovered that elephant groups separated by only a few hundred miles emit subtly different low-frequency rumbles. Those dialects might complicate friendships, alliances, or alarm calls when animals are translocated. 



The puzzle is part of a broader realization that many species possess local traditions - learned behaviors that function much like human culture.



To help researchers explore that idea, scientists at the <a href="https://www.arizona.edu/">University of Arizona</a> have launched the first open-access, global catalog of animal <a href="https://www.earth.com/news/saving-the-cultural-legacy-of-wild-animals/">cultures</a>.



<h2 class="wp-block-heading" id="h-mapping-animal-cultures">Mapping animal cultures</h2>



The <a href="https://viz.datascience.arizona.edu/ACDB/">Animal Culture Database</a> brings together hundreds of peer-reviewed reports on socially learned behaviors - from whales’ evolving migration routes to chimpanzees’ stone-tool know-how.



Kiran Basava is the paper’s lead author and a postdoctoral research associate at the University of Arizona.



“There is a consensus among animal behavior researchers that cultural traditions and socially learned behaviors are important to conservation,” said Basava. "There are decades of research investigating these behaviors across different species that are scattered throughout the literature."



"We synthesized that work to facilitate creative research and discussions about how culture is defined across different species, as well as how animals respond to different environmental disturbances caused by humans.”



<h2 class="wp-block-heading" id="h-animal-culture-by-region">Animal culture by region</h2>



The database centers on an interactive world map dotted with pins. Click on a marker and you can read about orangutans’ nesting tricks in Borneo, humpback <a href="https://www.earth.com/news/hidden-patterns-in-whale-songs-predict-ecosystem-shifts/">whales</a>’ complex songs off Tonga, or urban crows that drop nuts at traffic lights so cars will crack them open.



A search panel lets visitors filter by species, behavior type, or geographic region. For example, it reveals how rats in European forests learned to peel pinecones, or how certain <a href="https://www.earth.com/news/some-birds-trick-their-way-into-mating-by-removing-testosterone-from-their-bodies/">birds</a> remodeled mating dances after wildfires changed their habitat.



<h2 class="wp-block-heading" id="h-building-a-living-archive">Building a living archive</h2>



To assemble the resource, Basava and colleagues combed through thousands of journal articles published over several decades. 



The experts screened more than 1,000 promising papers. From those, they coded 121 into the pilot version - covering 30 mammalian, 30 avian, and one insect species. The team is adding 600 more studies and will soon let other scientists upload their own findings.



Study co-author Cristian Román-Palacios, an assistant professor of information science, said the tool could transform how researchers study cultural evolution.



“You can investigate the origins of culture by not just tracing it back to humans, but by seeing how much variance there is between different species and asking what drives those differences,” explained Professor Román-Palacios.



“Culture is not just a human phenomenon, and this database can help investigate what drives culture across the animal kingdom.”



<h2 class="wp-block-heading" id="h-cultural-loss-risks-extinction">Cultural loss risks extinction</h2>



Understanding animal culture is more than academic curiosity. Conservationists are realizing that an <a href="https://www.earth.com/news/elephants-may-be-the-first-non-human-animals-to-call-each-other-by-names/">elephant dialect</a>, a whale migration route, or a songbird melody can be as crucial as genetics for a population’s survival.



Human-driven habitat loss, noise pollution, and climate change threaten to erase those traditions. If relocated elephants cannot communicate with resident herds, or if dam construction blocks a salmon run taught across generations, restoration projects may fail.



By pooling case studies in one searchable hub, the database helps practitioners identify culturally important behaviors that need protection - much like <a href="https://www.unesco.org/en">UNESCO</a>’s list of human cultural heritage.



The data can also reveal patterns: Are populations with richer cultural repertoires more resilient to disturbance? Do species that lose key traditions decline faster?



<h2 class="wp-block-heading" id="h-science-meets-animal-tradition">Science meets animal tradition</h2>



The experts hope educators will use the site to teach evolutionary biology, while data scientists mine the entries for global trends. Basava envisions adding tools to visualize how behaviors spread over time, akin to epidemiological models for disease.



Future iterations may incorporate audio clips of vocalizations or video of <a href="https://www.earth.com/news/some-fish-use-tools-to-crack-open-prey/">tool use</a>, creating a multimedia atlas of animal ingenuity. 



The designers also plan multilingual interfaces to attract contributions from researchers worldwide, including Indigenous observers whose knowledge often predates academic studies.



<h2 class="wp-block-heading" id="h-culture-isn-t-just-human">Culture isn’t just human</h2>



The project resonates with a paradigm shift in biology: culture is no longer viewed as uniquely human. 



From dolphins that pass down signature whistles to capuchin monkeys that adopt local grooming fashions, <a href="https://www.earth.com/news/food-availability-influences-social-learning-among-orangutans/">social learning</a> pervades the animal kingdom. Recognizing those parallels can inform debates about animal welfare and cognitive rights, the authors note.



And it may reshape how humans see ourselves. If elephants currently need a translator, perhaps conservation must consider not just where animals live. It should also account for how they live - their languages, crafts, and customs forged over millennia.



For now, the Animal Culture Database offers anyone with an internet connection a front-row seat to those hidden worlds. The database preserves animal-taught traditions and reminds us that culture extends beyond just the human species.



The study is published in the journal <a href="https://www.nature.com/articles/s41597-025-05315-y">Nature Scientific Data</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

From rumbles to rituals: Scientists map the cultures of the animal kingdom

Relocating elephants to fresh herds can boost genetics and social...

Close-up,View,Of,Hand,Turning,Down,The,Volume,Of,Smartphone

A new study from Kyung Hee University explores how phones in "silent mode" may hold the key to healthier minds at work. 



Researchers examined whether a mobile mindfulness training (MMT) program could improve stress, burnout, and work engagement among office workers.



The trial at <a href="https://www.khu.ac.kr/eng/user/main/view.do" target="_blank" rel="noreferrer noopener">Kyung Hee University</a> included 114 participants, randomly assigned to either an experimental or control group. 



Those in the experimental group used a mindfulness app called InMind for four weeks, while the control group delayed their participation until the second half of the eight-week study.



Assessments were conducted before the program, at the end of four weeks, and again at the eight-week mark. Outcomes included burnout, perceived stress, engagement at work, mindfulness, and vitality. 



The study found clear benefits to the mindfulness app, with reduced stress and increased focus among participants.



Some of the strongest results were linked to participants who adopted broader lifestyle changes alongside the app, such as silencing their <a href="https://www.earth.com/news/digital-distraction-the-real-culprit-isnt-your-phone/">phones</a>. 



Some people never let their phones make a sound. The habit raises more than a few eyebrows. Psychology research says the choice speaks volumes.



<h2 class="wp-block-heading" id="h-silent-phones-and-personal-space">Silent phones and personal space</h2>



“Your cognitive capacity is significantly reduced when your smartphone is within reach, even if it’s off,” said <a href="https://www.mccombs.utexas.edu/faculty-and-research/faculty-directory/profile/?username=aw33587" target="_blank" rel="noreferrer noopener">Adrian Ward</a>, an assistant professor at the <a href="https://www.mccombs.utexas.edu/" target="_blank" rel="noreferrer noopener">McCombs School of Business</a>, University of Texas at Austin. According to a <a href="https://www.journals.uchicago.edu/doi/full/10.1086/691462" target="_blank" rel="noreferrer noopener">study</a> by Ward and colleagues, even a silent phone pulls at the mind. 



People who mute their devices often tuck them away as well, reclaiming cognitive capacity and a calm workspace. The absence of chirps removes the expectation of immediate responsiveness. 



That choice signals respect for personal boundaries. They decide when contact happens instead of letting a ringtone choose the moment.



Over time friends and colleagues learn to text first and wait, reinforcing the owner’s sense of autonomy. The boundary is not a wall that shuts <a href="https://www.earth.com/news/attractive-people-have-more-career-opportunities-and-success/">people</a> out, it is a gate that opens on the owner’s schedule, a subtle distinction that turns silence into courtesy rather than avoidance.



<h2 class="wp-block-heading" id="h-taking-charge-of-your-time">Taking charge of your time</h2>



Disruptions consume more than the seconds they steal. <a href="https://www.ics.uci.edu/~gmark/chi08-mark.pdf" target="_blank" rel="noreferrer noopener">Researchers</a> estimate that after an interruption it can take 23 minutes and 15 seconds to regain full focus, a toll silent‑phone users are keen to avoid. By controlling notification windows, they group replies into set blocks and shave hours off the week.



Life today overflows with micro‑interactions that feel urgent but rarely are. Muting notifications teaches the brain to sort urgent from merely loud. 



Once the habit forms, the mind anticipates longer arcs of concentration, and projects that used to stall now reach completion in shorter calendar time.



The cumulative effect mirrors compound interest, with every rescued minute growing into larger stretches of productive time. That payoff is especially visible in creative or analytical <a href="https://www.earth.com/news/employees-need-vacations-to-fully-disengage-from-work/">work</a> where even a small break can fracture thought.



<h2 class="wp-block-heading" id="h-silent-phones-and-mindfulness">Silent phones and mindfulness</h2>



The same crowd often embraces mindfulness, turning the once‑noisy handset into a pocket coach. A four‑week mobile mindfulness program lifted attention and vitality among Korean office workers, showing that a quiet <a href="https://www.earth.com/news/phone-bans-dont-help-children-learn-to-navigate-the-digital-world/">phone</a> can foster calm rather than craving. 



Muting alerts removes the constant tug back to the screen, creating space for an intentional breathing exercise instead of a reflexive swipe.



Clinicians note that the first step in any attention‑training protocol is reducing external triggers, and the silent setting accomplishes that task before meditation even begins. 



Because the phone stays available for emergencies, the user keeps the benefits of mobility while pruning the anxiety‑inducing soundtrack.



Practitioners say the rhythm sticks. Once the brain associates <a href="https://www.earth.com/news/silent-mind-when-the-inner-voice-fades/">silence</a> with steady breathing, the simple state of being unreachable cues relaxation. 



Colleagues notice the difference, describing these individuals as present, unhurried, and harder to rattle under pressure.



<h2 class="wp-block-heading" id="h-silent-phones-reduce-stress">Silent phones reduce stress</h2>



Noise primes the body for action even when the message is trivial. 



“Our research has shown that attention distraction can lead to higher stress, a bad mood, and lower productivity,” wrote <a href="https://www.ics.uci.edu/~gmark/chi08-mark.pdf" target="_blank" rel="noreferrer noopener">Gloria Mark</a>, a professor of informatics at the <a href="https://uci.edu/" target="_blank" rel="noreferrer noopener">University of California, Irvine</a>.



Keeping the ringtone off shields the nervous system from that steady stream of alerts, letting heart rate and cortisol stay low for longer stretches. 



Physiologically, every ping can produce a brief spike in sympathetic nervous activity, a response designed for survival but unhelpful when the alert is a discount code.



Subtracting hundreds of such spikes each day eases the background hum of tension that many workers accept as normal. Many report better sleep as well, because no beep tempts them to check one last ping at midnight.



<h2 class="wp-block-heading" id="h-chasing-depth-over-buzz">Chasing depth over buzz</h2>



A single ringtone can shatter the fragile cadence of heartfelt talk. Silent‑phone people stay fully engaged, catching pauses and tone shifts that others miss. The result is conversation that feels stitched together instead of patch‑worked between glances at a glowing slab.



That depth pays dividends in trust, an asset that cannot be captured by screen time metrics but shows up in stronger social support. 



Observers often describe silent‑phone people as ‘good listeners,’ a reputation that circles back to benefit them in leadership and collaboration settings. Deeper bonds form because presence, like any gift, gathers value through its rarity.



<h2 class="wp-block-heading" id="h-working-in-the-flow">Working in the flow</h2>



“People checked their phones more often when their devices were in silent mode,” said S. Shyam Sundar, James P. Jimirro Professor of Media Effects in the <a href="https://bellisario.psu.edu/" target="_blank" rel="noreferrer noopener">Donald P. Bellisario College of Communications</a> and co-director of the <a href="https://bellisario.psu.edu/research/centers/medialab" target="_blank" rel="noreferrer noopener">Media Effects Research Laboratory</a>.



The effect was strongest among people high in fear of missing out, yet seasoned muters offset it by putting the phone out of sight, breaking the feedback loop between silence and anxiety. 



Experienced muters also disable lock‑screen previews, removing visual bait that can reel them back in after they glance at the clock.



By orchestrating sound, sight, and distance, they create a layered defense against distraction, similar to noise‑canceling <a href="https://www.earth.com/news/healing-through-headphones-personalized-music-can-reduce-pain/">headphones</a> for the mind. 



Once out of reach, the device loses power to fracture burnout‑prone workflows, letting users sink into the state psychologists call “flow.”



<h2 class="wp-block-heading" id="h-self-awareness-on-silent-mode">Self‑awareness on silent mode</h2>



At the core sits self‑knowledge. Silent‑phone users recognize how easily sound hijacks thought, so they craft environments that support their goals instead of relying on raw willpower. 



Put simply, they have run the experiment on themselves and kept the setting that helps them move through the day with intention.



The same insight guides them to set bedtimes, plan reflective walks, and carve reading hours free from screens. 



Putting your phone on silent mode is a small ritual, yet it broadcasts a larger message: attention is finite, worth protecting, and best spent by conscious choice.



The study is published in <a href="https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1440824/full" target="_blank" rel="noreferrer noopener">Computers in Human Behavior</a>.



-----



Like what you read?<a href="https://www.earth.com/subscribe/"> Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on<a href="https://www.earth.com/earthsnap/"> EarthSnap</a>, a free app brought to you by<a href="https://www.earth.com/author/eralls/"> Eric Ralls</a> and Earth.com.



-----

People who keep their cell phones on "silent mode" share similar psychological traits

A new study from Kyung Hee University explores how phones...

Bird species add color, movement, and sound to our world. They pollinate plants, control pests, and spread seeds. But their future is in danger.



A new study from the <a href="https://www.reading.ac.uk" target="_blank" rel="noreferrer noopener">University of Reading</a> warns that climate change and habitat destruction threaten global bird diversity. 



The loss of unique birds like the bare-necked umbrellabird, helmeted hornbill, and yellow-bellied sunbird-asity would shrink the variety of bird forms that support <a href="https://www.earth.com/news/big-brains-and-wide-ranges-cant-save-birds-from-climate-change/">ecosystems</a>.



This projection triples all recorded bird extinctions since 1500 CE. Even with protection from hunting, habitat loss, and climate change, 250 species may still disappear. Some birds are now too fragile to survive without direct help.



“Many birds are already so threatened that reducing human impacts alone won't save them. These species need special recovery programs, like breeding projects and habitat restoration, to survive,” explained Kerry Stewart, lead author of the study.



“We face a bird extinction <a href="https://www.earth.com/news/birds-are-struggling-to-keep-pace-with-a-warming-climate/">crisis</a> unprecedented in modern times. We need immediate action to reduce human threats across habitats and targeted rescue programs for the most unique and endangered species.”



<h2 class="wp-block-heading" id="h-large-bird-species-are-most-at-risk">Large bird species are most at risk</h2>



The researchers studied nearly 10,000 bird species using IUCN Red List data and advanced models. 



The results showed that large-bodied birds are especially at risk. These birds struggle more with hunting pressure and climate stress. Birds with broad wings face severe danger from habitat destruction, especially in forests.



The study went beyond just species counts. It measured the expected loss of “functional diversity,” a term describing the variety of bird shapes, diets, and behaviors. 



Under current trends, global bird functional diversity could fall by about 3.2% in the next 100 years. This drop may sound small, but it would seriously damage ecosystems. 



Large, distinct <a href="https://www.earth.com/news/bird-evolution-timeline-pushed-back-20-million-years-by-baminornis-zhenghensis-discovery/">species</a> often provide unique services. Their disappearance would leave functional gaps that smaller or similar birds cannot fill.



<h2 class="wp-block-heading" id="h-limits-of-protection-alone">Limits of protection alone</h2>



The researchers tested three future scenarios: complete, partial, and minimal threat abatement. In the best case, where all human threats were removed across species ranges, around 250 species would still go extinct. That is nearly half of all projected losses, even with ideal conservation.



Some birds, like the Cebu flowerpecker, remain highly vulnerable despite facing few listed threats. With fewer than 70 individuals left, they may vanish without specific recovery steps like habitat restoration or captive breeding.



The study shows that reducing threats is not enough. Many species are already too close to the brink. Past damage, small populations, and isolated habitats all contribute to ongoing <a href="https://www.earth.com/news/birds-are-molting-earlier-in-the-fall-as-seasons-shift/">risks</a>.



<h2 class="wp-block-heading" id="h-threats-to-rare-bird-species">Threats to rare bird species</h2>



The research evaluated six main threats: habitat loss, hunting, climate change, invasive species, disturbance, and pollution. 



Habitat loss contributed the most to species decline, affecting over 1,600 species. Yet when it comes to preserving unique bird traits, other threats matter more.



Driver-specific results showed that reducing hunting or accidental deaths helped conserve rare bird features more effectively, even if fewer total species were saved. That means some threats disproportionately affect birds with uncommon traits.



Birds with long tails and short beaks, for example, benefited more from reduced hunting. Birds with broad wings responded better to protection from habitat destruction. These patterns help tailor conservation actions to bird traits most at risk.



<h2 class="wp-block-heading" id="h-strategic-recovery-of-unique-species">Strategic recovery of unique species</h2>



One solution stood out: target the most unique birds for rescue. The researchers created a list of 200 functionally unique species. Protecting just the top 100 could conserve over two-thirds of global bird functional diversity.



These birds include nectar-feeders, scavengers, and seed dispersers. From the Sulu hornbill to the southern royal albatross, many are island-dwelling, wide-ranging, or limited to one location. They carry traits that help regulate temperature, shape ecosystems, and fill rare ecological roles.



Preventing the extinction of around 37 of these birds could achieve this 68% protection goal. Since past efforts have already saved 21 to 32 bird species since 1993, this new goal appears feasible with commitment.



<h2 class="wp-block-heading" id="h-what-must-be-done-now">What must be done now</h2>



Even in optimistic futures, threats cannot be erased quickly or completely. Species recovery programmes, including in-situ and ex-situ measures, are needed for the most vulnerable.



“Stopping threats is not enough,” said Professor Manuela Gonzalez-Suarez. “Prioritizing conservation programs for just 100 of the most unusual threatened birds could save 68% of the variety in bird shapes and sizes. This approach could help to keep ecosystems healthy.”



Habitat protection remains key. But to safeguard ecosystem resilience, conservationists must also think about functional diversity, not just species counts.



The coming century will test humanity’s will to preserve Earth's avian legacy. Without sharp decisions and bold action, we risk losing many birds and the ecological balance they help maintain.



The study is published in the journal <a href="https://www.nature.com/articles/s41559-025-02746-z" target="_blank" rel="noreferrer noopener">Nature Ecology &amp; Evolution</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Hundreds of bird species could vanish in the next century

Bird species add color, movement, and sound to our world....

Heart disease remains the leading cause of death in the United States, but the specific types causing death have shifted.



From 1970 to 2022, deaths from heart attacks dropped by 89 percent - a major shift. In the same time period, deaths from other heart problems like heart failure, arrhythmias, and high blood pressure-related conditions rose by 81 percent.



Dr. Sara King is a second-year resident in the Department of Medicine at the <a href="https://med.stanford.edu" target="_blank" rel="noreferrer noopener">Stanford School of Medicine</a> in California.



“This distribution shift in the types of <a href="https://www.earth.com/news/changing-one-thing-about-this-everyday-task-cuts-heart-disease-risk-in-half/">heart</a> disease people were dying from the most was very interesting to us,” said Dr. King. “This evolution over the past 50 years reflects incredible successes in the way <a href="https://www.earth.com/news/drinking-this-amount-of-coffee-helps-prevent-heart-disease-and-diabetes/">heart</a> attacks and other types of ischemic heart disease are managed.”



<h2 class="wp-block-heading" id="h-treatment-reduced-heart-attack-deaths">Treatment reduced heart attack deaths</h2>



In 1970, most people who died from heart disease had a heart attack. By 2022, only 29% of ischemic heart disease deaths were from heart attacks, while the rest were from chronic ischemic disease. 



Emergency response and hospital care has improved in the United States. CPR, defibrillators, and coronary care units have helped. Imaging tools like angiography arrived in the 1970s, and angioplasty followed in 1977. Stents and thrombolytics came in the 1980s and 1990s.



Medications like statins, beta blockers, and blood thinners have become common. After 2009, doctors got access to PCSK9 inhibitors and better tests to detect <a href="https://www.earth.com/news/heart-disease-remains-the-leading-cause-of-death-worldwide/">heart</a> attacks.



<h2 class="wp-block-heading" id="h-habits-and-policies-supported-heart-health">Habits and policies supported heart health</h2>



Smoking rates dropped. In 1970, 40% of adults smoked. In 2019, that fell to 14 percent. People moved more. Cholesterol and blood pressure guidelines improved, and more patients took medication.



Dr. Keith Churchwell, the 2024-2025 <a href="https://www.heart.org" target="_blank" rel="noreferrer noopener">American Heart Association</a> volunteer president, is an associate clinical professor at the <a href="https://medicine.yale.edu" target="_blank" rel="noreferrer noopener">Yale School of Medicine</a> and an adjunct associate professor at the <a href="https://medschool.vanderbilt.edu" target="_blank" rel="noreferrer noopener">Vanderbilt School of Medicine</a>.



“Through the nearly $6 billion dollars the Association has invested in scientific research since 1948, we have enhanced the knowledge of how we diagnose and treat heart disease in almost all forms,” noted Dr. Churchwell.



<h2 class="wp-block-heading" id="h-risk-factors-are-rising-again">Risk factors are rising again</h2>



Obesity rose from 15% to 40% between 1970 and 2022. Diabetes, including prediabetes, now affects half of all adults. Almost 50% of adults live with <a href="https://www.earth.com/news/heart-cells-grown-in-space-may-help-heal-damaged-hearts/">hypertension</a>.



People also live longer. In 1970, life expectancy was 70.9 years. In 2022, it reached 77.5. Older adults face higher risks for heart failure, atrial fibrillation, and other lasting heart problems.



The total heart disease death rate dropped by 66 percent, but the type of heart disease causing death shifted. Ischemic deaths fell, while deaths from other heart conditions rose. Today, chronic problems cause more cases.



“We’ve won major battles against heart attacks, however, the war against heart disease isn’t over,” said Dr. King.



<h2 class="wp-block-heading" id="h-healthy-habits-prevent-heart-disease">Healthy habits prevent heart disease</h2>



“Now that people are surviving heart attacks, we are seeing a rise in other forms of heart disease like heart failure,” noted Dr. Latha Palaniappan, associate dean for research at Stanford University School of Medicine.



“The focus now must be on helping people age with strong, healthy hearts by preventing events, and prevention can start as early as childhood.”



The American Heart Association highlights eight important goals to protect heart and brain health. A healthy diet comes first. Choosing fruits, vegetables, whole grains, and lean proteins can lower bad cholesterol and support heart function. 



It's not just about food, though. Regular physical activity keeps the heart strong, improves circulation, and helps manage body weight. This could mean a structured workout or simply walking more each day.



<h2 class="wp-block-heading" id="h-further-steps-to-protect-heart-health">Further steps to protect heart health</h2>



Smoking damages blood vessels, raises blood pressure, and increases the risk of both stroke and heart attack. Once someone stops smoking, the body starts to heal. The risk of cardiovascular complications begins to drop. 



Sleep matters, too. People who get enough quality rest give their hearts time to recover and maintain a steady rhythm.



Managing key health markers is just as critical. Keeping a healthy weight takes pressure off the heart and reduces the risk of chronic disease. Controlling cholesterol keeps arteries clear and lowers the chance of a blockage. 



Blood sugar control helps avoid complications tied to diabetes, which often worsens heart problems. And stable blood pressure can prevent stroke, heart failure, and kidney damage.



When combined, these eight steps offer more than protection. They lay the groundwork for a healthier, longer life with fewer heart-related problems.



The study is published in the <a href="https://www.ahajournals.org/doi/10.1161/JAHA.124.038644" target="_blank" rel="noreferrer noopener">Journal of the American Heart Association</a>. 



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Heart disease kills differently now than five decades ago

Heart disease remains the leading cause of death in the...

Tiny clusters of drifting debris called "marine snow" shower through the ocean every day, ferrying food and carbon from the bright surface to the dark seafloor.



New <a href="https://www.pnas.org/doi/10.1073/pnas.2505085122" target="_blank" rel="noreferrer noopener">experiments</a> now show that the smallest flakes plunge more quickly than their larger cousins, overturning a century of textbook fluid dynamics and hinting at fresh twists in the planet’s carbon budget.



<h2 class="wp-block-heading" id="h-understanding-marine-snow-the-basics">Understanding "marine snow" - the basics</h2>



This “snow” consists of dead and decaying animals, plankton, fecal matter, mucus, and other tiny detritus that clump together into slow-sinking flakes. 



Despite the whimsical name, marine snow plays a serious role in the ocean's ecosystem - it serves as a crucial source of food for many deep-sea organisms that live far below sunlight’s reach. 



Without this steady rain of carbon-rich material, life in the <a href="https://www.earth.com/news/human-trash-debris-now-found-in-deepest-parts-of-earths-seas-and-oceans-mediterranean/">ocean’s abyss</a> would be severely limited.



Beyond its ecological function, marine snow also influences Earth’s climate system. As it sinks, it transports carbon from the surface to the ocean floor, effectively removing it from the atmosphere for centuries or even longer. 



This process, known as the <a href="https://www.earth.com/news/marine-robots-are-exploring-the-oceans-role-in-climate-control/">biological carbon pump</a>, helps regulate global carbon dioxide levels and mitigate climate change.



<h2 class="wp-block-heading" id="h-smallest-marine-snow-sinks-faster">Smallest marine snow sinks faster</h2>



“It basically means that smaller particles can sink faster than bigger ones,” said Robert Hunt and colleagues at <a href="https://www.brown.edu/" target="_blank" rel="noreferrer noopener">Brown University</a> and the <a href="https://www.unc.edu/" target="_blank" rel="noreferrer noopener">University of North Carolina</a> at Chapel Hill, who led the study. 



That counterintuitive sprint happens only in <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/stratified-fluid" target="_blank" rel="noreferrer noopener">stratified fluids</a> such as the ocean, where density increases with depth.



When a porous flake soaks up salt from the layers it crosses, the added mass beats the drag that normally slows tiny objects. 



Because surface‐to‐depth density changes are gentle yet persistent, salt diffusion keeps boosting the <a href="https://oceanservice.noaa.gov/facts/marinesnow.html" target="_blank" rel="noreferrer noopener">flake’s weight</a> all the way down.



<h2 class="wp-block-heading" id="h-why-is-this-important">Why is this important?</h2>



Speed matters. The ocean’s <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GB007083" target="_blank" rel="noreferrer noopener">carbon biological pump</a> moves about 10.2  billion tons of carbon a year from sunlit waters toward long‑term storage below the <a href="https://oceanservice.noaa.gov/facts/thermocline.html" target="_blank" rel="noreferrer noopener">thermocline</a>. 



Faster‑than‑expected settling of small fragments may revise estimates of how much carbon actually reaches the deep, especially during spring plankton blooms when the ocean teems with fine detritus.



The same physics could alter the journey of <a href="https://oceanservice.noaa.gov/facts/microplastics.html" target="_blank" rel="noreferrer noopener">microplastics</a>. A recent global <a href="https://www.nature.com/articles/s41586-025-08818-1" target="_blank" rel="noreferrer noopener">survey</a> found that smaller plastic bits, under 0.004 inch, linger longer at mid‑depths than bigger shards. 



If porosity or biofilm growth changes their salt uptake, these particles might fall sooner than models predict and redistribute pollution hotspots on the seafloor.



<h2 class="wp-block-heading" id="h-how-marine-snow-sinks-through-layers">How marine snow sinks through layers</h2>



Hunt’s team built a four‑foot‑long tank whose density changed smoothly from fresh water at the top to salty water below, mimicking the open ocean’s gradient. Carefully controlled pumps dripped the two end‑member waters to create a stable linear stratification.



The researchers then 3D‑printed molds and cast agar shapes (spheres, disks, and rods) with diameters from 0.04 to 0.4 inch. 



Like gelatin desserts, the <a href="https://www.sciencedirect.com/topics/immunology-and-microbiology/agar" target="_blank" rel="noreferrer noopener">agar particles</a> were riddled with pores that quickly exchanged water and salt with their surroundings.



High‑speed cameras tracked each particle’s plunge through the tank. “We ended up with a pretty simple formula where you can plug in estimates for different parameters and get reasonable estimates of the sinking speed,” said <a href="https://engineering.brown.edu/people/daniel-m-harris" target="_blank" rel="noreferrer noopener">Daniel Harris</a>, an associate professor of engineering at Brown who oversaw the work.



The observations matched the new equation: among spheres, a one‑millimeter bead beat a four‑millimeter bead to the bottom. 



For flat or rod‑shaped bodies, the thinnest dimension set the pace, allowing needle‑like fragments to blitz past bulkier shapes of the same mass.



<h2 class="wp-block-heading" id="h-salt-makes-porous-marine-snow-fall-faster">Salt makes porous marine snow fall faster</h2>



Classical drag calculations assume an object’s density stays fixed as it falls. Porous bodies break that rule because water flows through them, letting dissolved salt accumulate inside.



The model hinges on <a href="https://www.sciencedirect.com/topics/engineering/porosity" target="_blank" rel="noreferrer noopener">porosity</a>, solute <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/diffusivity" target="_blank" rel="noreferrer noopener">diffusivity</a>, and the <a href="https://aslopubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1002/lom3.10316" target="_blank" rel="noreferrer noopener">vertical density gradient</a>. If salt absorption boosts density faster than drag slows descent, size becomes a liability and small wins the race.



This diffusion‑limited regime likely dominates for fluffier aggregates made of <a href="https://oceanservice.noaa.gov/facts/phyto.html" target="_blank" rel="noreferrer noopener">phytoplankton</a> remains, fecal pellets, or dust‑laden snow. Less porous grains of sand or shell should still follow the familiar bigger‑falls‑faster script.



<h2 class="wp-block-heading" id="h-fast-sinking-marine-snow-changes-estimates">Fast-sinking marine snow changes estimates</h2>



Biogeochemical models track how quickly carbon sinks, gets eaten, or dissolves on the way down. Underestimating the speed of fine aggregates could inflate estimates of mid‑water remineralization and shortchange deep‑sea sequestration.



<a href="https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification" target="_blank" rel="noreferrer noopener">NOAA</a> notes that the ocean absorbs about 30 percent of the carbon dioxide humans emit each year, buffering climate change. Tweaking particle speeds could shift where, and how long, that captured carbon stays locked away.



Some climate engineers are exploring methods that encourage fast‑sinking flakes, from adding minerals that ballast algae to growing kelp for deep burial. 



Knowing exactly which sizes and shapes drop quickest will sharpen those interventions and gauge possible ecological side effects.



<h2 class="wp-block-heading" id="h-lessons-for-plastic-pollution">Lessons for plastic pollution</h2>



Plastic fragments often pick up biofilms, turning them into tiny sponges that absorb salts and organic goo, much like marine snow. 



If that boosts density, millimeter‑scale fibers might leave surface waters sooner than remote sensing suggests.



A plastic snowfall could ferry toxins to bottom feeders and alter food webs once thought safe from floating litter. Policy aimed at surface cleanup alone may miss this hidden pathway.



Researchers also found that elongated pieces settle according to their thinnest axis. That means synthetic fibers shed from clothing, typically long and narrow, may descend even faster than spheres of equal volume.



<h2 class="wp-block-heading" id="h-testing-in-real-ocean-and-improving-models">Testing in real ocean and improving models</h2>



Hunt and Harris plan to partner with oceanographers to drop custom particles over deep moorings and compare lab predictions with real‑world drifts. They also aim to explore how temperature gradients, common near polar ice and hydrothermal vents, tweak the balance between drag and diffusion.



Back on land, modelers are already folding the new equation into regional carbon budgets and microplastic fate simulations. Small marine snow flakes, once dismissed as slow movers, are entering the spotlight, reminding scientists that size is only skin deep when salt can seep inside.



The study is published in <a href="https://www.pnas.org/doi/10.1073/pnas.2505085122" target="_blank" rel="noreferrer noopener">Proceedings of the National Academy of Sciences</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Tiny "marine snow" particles in the oceans defy the laws of physics

Tiny clusters of drifting debris called "marine snow" shower through...

Back,View,Of,Dog,Talking,To,Dog,Friends,In,Video

Spending time with dogs brings comfort. But can watching them virtually help too? A new study says yes. The researchers found that a five-minute video of a therapy dog can ease stress almost as much as an in-person visit.



Led by Dr. John-Tyler Binfet from&nbsp;<a href="https://ok.ubc.ca" target="_blank" rel="noreferrer noopener">UBC Okanagan</a>&nbsp;and Dr. Christine Tardif-Williams from&nbsp;<a class="" href="https://brocku.ca/">Brock University</a>, the study tested the impact of virtual <a href="https://www.earth.com/news/therapy-dogs-on-campus-help-students-manage-stress-and-anxiety/">dog</a> videos on both students and non-students. Over 1,000 people took part, showing clear stress relief across groups.



“Our findings demonstrate that even with a virtual session, there was a significant reduction in stress among both the student population and the general public, regardless of age,” said Dr. Binfet.



<h2 class="wp-block-heading" id="h-how-therapy-dog-videos-created-calm">How therapy dog videos created calm</h2>



The virtual canine comfort modules were brief, calming, and thoughtfully made. They featured therapy dogs and handlers from the B.A.R.K. program, a known student well-being initiative.



Each video included a welcome message, land acknowledgment, gentle narration, and sensory prompts. Participants were asked to imagine petting the <a href="https://www.earth.com/news/therapy-dogs-reduce-emotional-exhaustion-and-work-burnout/">dog</a> and were guided to reflect on their emotions.



This method mimicked real therapy dog sessions without needing in-person attendance. It also gave viewers flexibility to watch from anywhere and at any time.



<h2 class="wp-block-heading" id="h-therapy-dog-videos-lowered-stress">Therapy dog videos lowered stress</h2>



This study included two phases: student participants (N = 963) and community members (N = 122). Both groups reported lower stress levels after the session. 



For students, average stress dropped from 3.33 to 2.53 on a five-point scale. For community members, the reduction was from 3.07 to 2.43.



Interestingly, women in the student group experienced more stress relief than men. Before watching, women reported higher stress. After viewing, their stress dropped to levels similar to male participants. Age, however, had no major influence on results.



<h2 class="wp-block-heading" id="h-beyond-the-pandemic-context">Beyond the pandemic context</h2>



This isn’t the first time virtual therapy <a href="https://www.earth.com/news/petting-a-dog-might-be-the-easiest-way-to-reduce-stress/">dog</a> sessions were studied. But this research took place after COVID-19 restrictions ended. That makes it more relevant today, as it reflects everyday conditions.



The findings confirm that people continue to benefit from virtual canine modules even when in-person options are available. 



The simplicity and low commitment of the videos help reduce stress without needing a formal setting.



<h2 class="wp-block-heading" id="h-who-benefits-most-from-virtual-sessions">Who benefits most from virtual sessions?</h2>



This method works for students, busy adults, or anyone avoiding therapy due to stigma. 



For example, one participant said: “I have thought about attending an in-person session on campus before since I love dogs but the interacting with humans made me anxious."



"No offense to anyone but this virtual <a href="https://www.earth.com/news/interacting-with-dogs-can-ease-physical-pain/">dog</a> session removes the unknown human interaction that may make people nervous."



The videos can serve as an easy first step toward mental health care. Researchers believe this “foot in the door” model could help people eventually seek further support.



<h2 class="wp-block-heading" id="h-short-and-effective-videos">Short and effective videos</h2>



The virtual modules were just five minutes long. Despite the short length, they led to measurable improvements in stress. 



Participants viewed videos on YouTube without scheduling anything. That made it very convenient and widely accessible.



This short duration also helped protect the welfare of therapy dogs. In virtual settings, dogs avoid the stress of busy live events. It’s better for them and still works for humans.



<h2 class="wp-block-heading" id="h-inclusive-and-accessible-therapy-sessions">Inclusive and accessible therapy sessions </h2>



The sessions were inclusive in design. People from different age groups, ethnicities, and life situations took part. 



Virtual delivery helps reach rural residents, people with social anxiety, or those who simply prefer solitude.



Modules could be tailored further to suit marginalized or neurodiverse audiences. Researchers recommend more collaboration between mental health professionals and human-animal interaction experts to design targeted content.



<h2 class="wp-block-heading" id="h-future-of-therapy-dog-research">Future of therapy dog research</h2>



The study had some limitations. It lacked a control group watching non-dog videos, so other calming factors weren’t ruled out. 



Also, long-term effects weren’t measured. Researchers want future work to track how long the stress relief lasts.



The gender imbalance in the sample also raises questions. Most participants were women, which matches past studies. Still, future research should explore how different genders experience virtual dog sessions.



Another future step could be combining these modules with mindfulness techniques. That might boost their calming impact even more.



<h2 class="wp-block-heading" id="h-feeling-better-with-little-effort">Feeling better with little effort</h2>



Virtual canine comfort videos offer a short, calming break with meaningful benefits. They help reduce stress, particularly for women and those who avoid traditional therapy settings. 



The videos are easy to access, require no special tools, and can reach people from all backgrounds.



In a time when stress and mental health challenges are rising, a simple dog video may be more powerful than we thought.



The study is published in the journal <a href="https://www.cabidigitallibrary.org/doi/10.1079/hai.2025.0015" target="_blank" rel="noreferrer noopener">Human-Animal Interactions</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Scientists prove that simply watching dogs on video can reduce stress and anxiety, no contact required

Spending time with dogs brings comfort. But can watching them...

In the watery world of fish evolution, feeding is everything. Success depends on catching food efficiently, whether it's darting prey or algae stuck to rocks. 



A recent study published in the journal PLOS Biology&nbsp;shows that fish face a basic anatomical choice: grow big teeth or evolve mobile jaws - they can’t do both.



Nick Peoples and colleagues at <a href="https://www.ucdavis.edu/">UC Davis</a> used high-speed videography and evolutionary models to investigate this trade-off across 161 ray-finned fish species.



Ray-finned fishes dominate the aquatic world, forming about half of all vertebrate species. Their feeding success hinges on two traits: long teeth that help damage or grip prey, and extendable jaws that produce suction for capturing elusive prey. Yet both features rarely appear in the same species.



<h2 class="wp-block-heading" id="h-bigger-teeth-less-mobile-jaws">Bigger teeth, less mobile jaws</h2>



The researchers analyzed videos to track how fish approached prey using three techniques: swimming forward (body ram), extending the jaws (jaw ram), or sucking prey in (suction). Most species (76%) relied on body ram, while suction rarely played a primary role.



The team found that tooth size closely matched feeding strategy. Fish with big teeth nearly always relied on body ram. Those with small teeth used jaw protrusion more effectively. 



There was no strong link between tooth size and suction use. The results support a simple pattern: the bigger the teeth, the less mobile the jaws.



<h2 class="wp-block-heading" id="h-tooth-size-limits-feeding-flexibility">Tooth size limits feeding flexibility</h2>



To explore the evolutionary basis of this mismatch, the team ran statistical models comparing species with different feeding behaviors. 



The results confirmed a tight trade-off: <a href="https://www.earth.com/news/small-fish-species-are-the-big-catch-of-the-future/">species</a> that use jaw ram evolved to have teeth four times smaller than species that rely on swimming strikes.



The study also showed that as teeth get larger, the diversity of feeding strategies drops sharply. Species with smaller teeth had more flexibility, combining jaw movement and suction in various ways. This flexibility was lost in fish with bigger teeth.



<h2 class="wp-block-heading" id="h-jaw-structure-shapes-fish-evolution">Jaw structure shapes fish evolution</h2>



Most <a href="https://www.earth.com/news/319-million-year-old-fish-holds-clues-about-brain-evolution/">ray-finned fish</a> grow replacement teeth inside the jawbone. This requires extra space, especially if the teeth are big. But extendable jaws are slim and fast-moving, with little room for large internal replacements.



The result? Fish with mobile jaws can’t support very large teeth. “This presents a dilemma for species with high jaw protrusion," noted the researchers.



Slim jaws that allow fast strikes limit space for growing new, large teeth. To make things harder, large teeth could slow a suction strike by creating drag or interfering with water flow. Fish that use suction likely keep their teeth small on purpose.



<h2 class="wp-block-heading" id="h-fish-adapt-to-keep-big-teeth">Fish adapt to keep big teeth</h2>



Some species sidestep this problem using special modifications. These include fused teeth in <a href="https://www.earth.com/news/what-grazing-halos-and-parrotfish-reveal-about-coral-reef-health/">parrotfish</a>, which form a beak, and stacked tooth structures in pufferfish that become dense cutting tools. 



Triggerfish attach teeth using soft tissue for more support, while butterflyfish evolved flexible tooth shafts.



These adaptations allow large-toothed species to exploit unique diets - like coral scraping, detritus collection, or even wood eating.



“When we looked into which species had exceptionally large teeth, we were surprised to find that they also have interesting modifications to the dental system, like the beak of parrotfish," said Peoples.



<h2 class="wp-block-heading" id="h-feeding-success-has-limits">Feeding success has limits</h2>



Fish evolution illustrates a simple but powerful rule: you can't always have it all. Both big teeth and mobile jaws help fish survive, but trying to evolve both seems to backfire.



“Many feeding innovations have evolved in fishes, and our results show that it is important to consider the interactions between these traits as some may actually be incompatible with each other," noted Peoples.



“High-speed videography really provides a unique view into fish feeding. IIt often reveals subtle movements and behaviors that you would not notice if only observing the fish in the <a href="https://www.earth.com/news/the-hidden-environmental-impacts-of-tropical-fish-aquariums/">aquarium</a>.”



<h2 class="wp-block-heading" id="h-bite-hard-or-strike-fast">Bite hard or strike fast</h2>



Fish species that evolved big teeth gave up jaw mobility but gained new dietary options. Species that evolved flexible jaws gained versatility but lost the power to grip or damage prey.



This study highlights how physical constraints can shape evolution. Even in a group as diverse as ray-finned fishes, nature imposes limits. 



Those limits may explain why fish face a fork in their evolutionary path: bite hard or strike fast - but never both.



The study is published in the journal <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003225" target="_blank" rel="noreferrer noopener">PLOS Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Why fish can’t evolve both powerful jaws and big teeth

In the watery world of fish evolution, feeding is everything....

There is an apparent paradox in evolutionary theory. The rate of evolution seems to run like a sprinter over a few million years yet crawl over tens of millions, a pattern so regular that textbooks use it to link microevolution with macroevolution.&nbsp;



For decades, biologists treated that apparent increase in evolutionary rate as biological truth, arguing that young groups diversify faster than old ones, shed species more quickly, and tweak body plans at record pace. 



<h2 class="wp-block-heading" id="h-evolutionary-rate-paradox">Evolutionary rate paradox </h2>



Early molecular studies showed that mutation rates estimated from contemporary samples were 5-20 times higher than those calibrated with fossils drawn from deep <a href="https://www.earth.com/news/physicists-confirm-the-incredible-existence-of-time-mirrors/">time</a>, jolting confidence in the evolutionary “<a href="https://www.biorxiv.org/content/10.1101/2023.12.02.569704v1" target="_blank" rel="noreferrer noopener">clock</a>.” 



Paleontologists spotted the same mismatch in the rock record: the evolutionary rate in newly arisen dinosaur lineages seemed faster than in lineages that had persisted for tens of millions of years.



Some theorists proposed that ecological opportunity drives early bursts, while competitive saturation dulls the pace later on. 



Others hinted that developmental constraints lock traits into “optimal” configurations and slow further change, an idea that made intuitive sense but resisted firm testing.



<h2 class="wp-block-heading" id="h-statistical-noise-warps-the-picture">Statistical noise warps the picture </h2>



A research team led by Brian C. O’Meara at the <a href="https://www.utk.edu/">University of Tennessee</a> and Jeremy M. Beaulieu at the <a href="https://www.uark.edu/" target="_blank" rel="noreferrer noopener">University of Arkansas</a> has recently investigated this paradox of evolutionary theory. 



O’Meara and Beaulieu built a simulation that treats every evolutionary rate estimate as a fraction - change in trait divided by elapsed <a href="https://www.earth.com/news/negative-time-observed-measured-tangible-in-new-quantum-experiments/">time</a> - and then distributed measurement error evenly across every numerator.



Because the denominator (time) varies wildly while the error does not, the ratio traces a <a href="https://math.libretexts.org/Bookshelves/Algebra/Algebra_and_Trigonometry_1e_(OpenStax)/12%3A_Analytic_Geometry/12.02%3A_The_Hyperbola" target="_blank" rel="noreferrer noopener">hyperbola</a> that plummets with age - exactly the pattern that inspired all those stories of adaptation.



“By employing a novel statistical approach, we found that this time‑independent noise … makes it seem like evolutionary rates increase over shorter time frames when, in fact, they do not,” explained O’Meara.&nbsp;



When the team randomized real datasets, shuffling trait differences while leaving times intact, the fake data reproduced more than 85 percent of the scatter found in genuine evolutionary rate studies. This level of mimicry stunned even longtime rate‑modelers.



<h2 class="wp-block-heading" id="h-running-the-numbers">Running the numbers</h2>



The analysis covered molecular substitutions in birds and primates, body‑size shifts in mammals and lizards, speciation surges in flowering plants, and extinction tallies drawn from conservation lists.&nbsp;



Across five independent datasets totaling almost 9,000 evolutionary rate estimates, the fitted curves showed the same steep drop in the first 10 million years followed by a flattening tail, just what the noise model predicts.



In one mammal dataset, the median coefficient of variation for repeated measurements at the same age was 0.59, meaning the standard <a href="https://www.earth.com/news/traditional-computers-verify-errors-made-by-quantum-computers/">error</a> was more than half the mean value. 



Put differently, five percent of those “measurements” would have placed the Eiffel Tower shorter than a giraffe or taller than twice its real height - an error band that is wide enough to drown any subtle biological signal.



<h2 class="wp-block-heading" id="h-viral-evolution-and-the-cosmos">Viral evolution and the cosmos</h2>



The statistical noise idea echoes work on viral evolution, where apparent mutation‑rate “decay” with time has been traced to mutational saturation and sampling bias rather than to fundamental shifts in replication chemistry.&nbsp;



Astronomers face a parallel dilemma: the “<a href="https://science.nasa.gov/missions/hubble/nasas-webb-hubble-telescopes-affirm-universes-expansion-rate-puzzle-persists/" target="_blank" rel="noreferrer noopener">Hubble tension</a>” arises because recent supernova surveys and ancient cosmic‑microwave‑background data give different expansion rates. 



Some physicists now attribute the Hubble discrepancy, at least partly, to mismatched error structures.



Both cases remind scientists that plotting a ratio (rate) against one of its components (<a href="https://www.earth.com/news/time-may-not-just-move-forward-experts-say-it-could-rewind/">time</a>) courts mathematical traps unless errors are modeled explicitly. 



The new study argues that evolutionary biology has been caught in just such a trap, mistaking geometry for genetics.



<h2 class="wp-block-heading" id="h-next-steps-in-evolutionary-rate-research">Next steps in evolutionary rate research</h2>



Comparative methods that search a phylogeny for bursts of trait change may flag any young <a href="https://evolution.berkeley.edu/the-tree-room/evolutionary-trees-a-primer/clades-within-clades/" target="_blank" rel="noreferrer noopener">clade</a> as “rapidly evolving” even when its true rate of change matches the background, simply because less time has accrued to dilute measurement error.



Diversification analyses that exclude small groups with zero speciation events risk overestimating average rates near the present, further skewing the perceived trend. 



O’Meara suggests that researchers of evolutionary theory adopt fixed‑window approaches, examining change per 100,000 years or per 1 million years, much as <a href="https://www.environmentalscience.org/dendrochronology-tree-rings-tell-us" target="_blank" rel="noreferrer noopener">dendrochronologists</a> study tree rings, thereby holding the denominator constant.



He also urges journals to require explicit error terms for trait means, branch‑length estimates, and dating calibrations - allowing models to partition signal from noise instead of forcing error to zero by fiat.



<h2 class="wp-block-heading" id="h-why-evolutionary-theory-matters">Why evolutionary theory matters</h2>



Far from closing the doors of research into evolution rates, the work clears the field to tackle fresh questions: which traits truly <a href="https://www.earth.com/news/quantum-tunneling-allow-particles-break-light-speed-barrier/">speed</a> up or slow down over time, and under what ecological or genetic circumstances? 



With the hyperbolic mirage out of the way, biologists can focus on signals that remain after accounting for error, signals that may illuminate how life diversifies, adapts, and sometimes stalls.



Tools developed for sequencing error in virology or for tip‑dating in paleogenomics could be repurposed to model measurement uncertainty in comparative datasets from diverse branches of the tree of life.&nbsp;



“Biology is rich in mysteries: actually answering one lets us move on to the next,” wrote the authors in an unpublished summary of their work. The statement highlights their view that solving the rate paradox frees, rather than constrains, evolutionary thought.



The study is published in <a href="https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1012458" target="_blank" rel="noreferrer noopener">PLOS Computational Biology</a>.



-----



Like what you read?<a href="https://www.earth.com/subscribe/"> Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on<a href="https://www.earth.com/earthsnap/"> EarthSnap</a>, a free app brought to you by<a href="https://www.earth.com/author/eralls/"> Eric Ralls</a> and Earth.com.



-----

Scientists debunk key evolutionary theory as "statistical noise"

There is an apparent paradox in evolutionary theory. The rate...

Killer whales have been spotted doing something unexpected: using seaweed to massage one another.



Experts observed them breaking off pieces of kelp, placing it between themselves and another whale, and rolling it between their bodies. The behavior looks deliberate - and it’s something researchers had never seen before.



The discovery was made by scientists at the Center for Whale Research, working with the <a href="https://www.exeter.ac.uk/">University of Exeter</a>. They used high-quality drone footage to study southern resident killer whales in the Salish Sea, off the coast of Washington State. 



What they saw was new: pairs of whales using kelp together in a way that might count as tool use - a first for marine mammals.



<h2 class="wp-block-heading" id="h-whales-shared-seaweed">Whales shared seaweed</h2>



Killer whales have long been known to engage in “<a href="https://www.earth.com/news/whales-play-with-seaweed-and-roll-in-its-antibacterial-properties/">kelping</a>,” a term used when they rub themselves with seaweed. But this new behavior goes further. The whales aren’t just grabbing kelp for themselves. They’re using it with each other - what the scientists are calling “allokelping.”



What makes this behavior stand out is how the kelp is used. Whales were seen selecting it, trimming it, and then coordinating with a partner to rub it between their bodies. That makes it more like tool-making than simple play.



“We were amazed when we first noticed this behavior,” said Dr. Michael Weiss of the <a href="https://www.whaleresearch.com/">Center for Whale Research</a>.



<h2 class="wp-block-heading" id="h-whales-favor-kin-for-kelping">Whales favor kin for "kelping"</h2>



The whales didn’t allokelp randomly. Most of the time, they did it with relatives - especially close maternal kin - or whales of similar age. The researchers think it may help strengthen social bonds or even benefit <a href="https://www.earth.com/news/mysterious-skin-disease-threatens-endangered-killer-whales/">skin health</a>.



“Bull kelp stalk is firm but flexible, like a filled garden hose, with a slippery outer surface. I suspect these features make it an ideal grooming tool,” said Weiss.



“What I find remarkable about this behavior is just how widespread it is in the population. Males and females of all life stages and from all three southern resident pods were seen using kelp in this way. All evidence points to it being an important part of their social lives.”



Allokelping was seen on two-thirds of the observation days. Based on the consistency, the researchers think it might be universal within the group.



<h2 class="wp-block-heading" id="h-quality-of-drone-footage">Quality of drone footage</h2>



So why hadn’t anyone noticed it before? The quality of drone footage made all the difference.



“This population of whales has been formally studied for 50 years - the best-studied <a href="https://www.earth.com/news/sign-of-the-times-solitary-orcas-are-hunting-great-whites/">orcas</a> on the planet - and yet major new discoveries can still be made,” said Rachel John, a graduate student studying animal behavior at the University of Exeter.



According to John, the researchers hadn’t noticed ‘allokelping’ before because the videos being collected from their previous aircraft weren’t of high enough quality, but the footage we’re getting now shows this behavior in great detail.



She recalled the moment they realized what they were seeing: “Drone cameras allow us to see things that were invisible to us from boats or the shore. I was watching one of those really close-up videos when I saw something that looked like a brown stick between two whales that were in contact with each other."



<h2 class="wp-block-heading" id="h-kelping-behavior-of-killer-whales">Kelping behavior of killer whales</h2>



John said her team didn’t think much of this at first, but they had also noticed pairs of whales staying in contact with each other for long periods - several minutes at a time.



"We looked back at lots of videos and realized that rubbing kelp between their bodies wasn’t just a one-off thing - it was happening all the time," she noted.



"Once we saw whales breaking off pieces of kelp intentionally, it became clear that this is not just play - this is something important in the social lives of the southern resident killer whales.”



<h2 class="wp-block-heading" id="h-the-importance-of-touch">The importance of touch </h2>



Professor Darren Croft, of the University of Exeter and the Center for Whale Research, thinks the answer lies in the importance of touch. “We know touch is really important," he said. “In primates - including humans - <a href="https://www.earth.com/news/scientists-discover-a-hidden-way-that-humans-feel-and-sense-touch/">touch</a> moderates stress and helps to build relationships."



“We know killer whales often make contact with other members of their group - touching with their bodies and fins - but using kelp like this might enhance this experience."



This behavior may also play a role in skin health. Whales and <a href="https://www.earth.com/news/dolphins-hear-special-whistles-and-change-their-behavior/">dolphins</a> use a variety of strategies to shed dead skin - and this could be yet another adaptation serving that purpose.



“Brown algae like bull kelp also have antibacterial and anti-inflammatory properties that may provide further benefits to the whales," Croft said.



Scientists are now working to confirm these initial findings and investigate the social and skin health benefits of this behavior.



<h2 class="wp-block-heading" id="h-a-population-on-the-brink">A population on the brink</h2>



As of July 2024, there were only 73 southern resident killer whales left. They don’t breed with other killer whale groups. That makes them a closed population - and a critically endangered one.



Their main food source is <a href="https://www.earth.com/news/distinctly-different-chinook-salmon-are-part-of-the-same-population/">Chinook salmon</a>, which is also declining. The salmon face pressure from overfishing, habitat destruction, climate change, and pollution. On top of that, whales have to deal with noise and chemical pollution from boats and industry.



Dr. Weiss warned that without significant change, the future of southern resident killer whales looks grim.



“Under the status quo, all of our projections indicate the population will continue to decline," he said. “They are struggling to find enough of the large Chinook salmon needed to survive and successfully rear their young.



“We often think about biodiversity in terms of protecting the phenotypic variation we see in animal populations - such as differences in size, shape, and color. However, conserving cultural and behavioral variation may be just as important."



Dr. Weiss added that allokelping is yet another piece of evidence of the southern residents’ uniqueness. If we lose them, he said, we lose so much more than 73 individual animals or a genetic lineage.



<h2 class="wp-block-heading" id="h-vanishing-kelp-forests">Vanishing kelp forests</h2>



The new findings also suggest that the future survival of southern resident killer whales may face an added threat: the decline of kelp forests they rely on for grooming tools. This decline is being driven by rising ocean temperatures linked to global warming.



Protecting the kelp forests where these whales craft their grooming tools could be vital to preserving their unique cultural behavior. It may also help ensure the long-term survival of the southern resident killer whale population.



The full study was published in the journal <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(25)00450-6?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982225004506%3Fshowall%3Dtrue">Current Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Killer whales use kelp to massage and groom each other

Killer whales have been spotted doing something unexpected: using seaweed...

The hairy frogfish looks more like a tuft of drifting seaweed than a hunter. Yet beneath the mop of filaments sits an anglerfish that can inhale prey faster than most cameras can blink.



Marine ecologist Dr. Maarten De Brauwer of <a href="https://research.csiro.au/environomics/our-people/early-career-researchers-separate-bios/dr-maarten-brauwer/" target="_blank" rel="noreferrer noopener">Curtin University</a> first noticed that the fish’s lure shines neon orange under blue light, while the rest of the body stays dull. 



His team’s 2016 field <a href="https://link.springer.com/article/10.1007/s00338-016-1493-1" target="_blank" rel="noreferrer noopener">survey</a> on Philippine reefs linked that glow to free‑swimming worms that share the same color and size.



<h2 class="wp-block-heading" id="h-hairy-frogfish-hides-by-copying-reef-textures">Hairy frogfish hides by copying reef textures</h2>



The hairy frogfish belongs to the anglerfish <a href="https://www.earth.com/news/frogfish-lure-their-prey-with-a-built-in-fishing-rod-and-bait/">family</a>, but instead of lurking in the deep it prowls coral rubble in tropical shallows. 



A coat of branching spinules lets it copy the texture of algae, sponge, or coral until the head seems to vanish into the seafloor.



Individuals can swap pattern and shade within weeks, shifting from lemon yellow to mottled black as sediment, light, and growth change around them. 



That rapid makeover is a textbook example of <a href="https://www.sciencedirect.com/science/article/abs/pii/S0022519323002801" target="_blank" rel="noreferrer noopener">Batesian mimicry</a>, a tactic where harmless looks discourage predators while inviting unsuspecting prey.



Sight alone does not give the trick away, because even the fish’s eyes carry radiating stripes that obscure the pupil. 



Only the stubby “arm” formed by the first dorsal spine, called the <a href="https://www.britannica.com/science/illicium-zoology" target="_blank" rel="noreferrer noopener">illicium</a>, rises above the camouflage like a tiny fishing pole.



<h2 class="wp-block-heading" id="h-how-the-glowing-lure-helps-the-hairy-frogfish">How the glowing lure helps the hairy frogfish</h2>



“These observations indicate a novel function, prey capture, for biofluorescence in coral reef fishes,” wrote De Brauwer. 



Under daylight the illicium ends in a dull worm‑shaped tassel, but blue‑filtered lamps reveal intense <a href="https://www.nature.com/articles/s41598-020-59528-9" target="_blank" rel="noreferrer noopener">biofluorescence</a> that converts blue light to orange. 



The idea fits a wider pattern, because a survey of 180 fish species found <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0083259" target="_blank" rel="noreferrer noopener">glowing pigments</a> clustered in cryptic reef lineages. 



<a href="https://www.amnh.org/" target="_blank" rel="noreferrer noopener">American Museum of Natural History</a> ichthyologist <a href="https://www.amnh.org/research/staff-directory/john-s-sparks" target="_blank" rel="noreferrer noopener">Dr. John Sparks</a> noted that “biofluorescence is especially common and morphologically variable in cryptically patterned coral‑reef lineages,” hinting at communication or hunting value.



By matching the fluorescent worms that drift over sandy bottoms at night, the lure likely acts as a living decoy. 



The <a href="https://www.earth.com/news/deep-sea-anglerfish-defy-evolutionary-expectations/">fish</a> twitches the tip in arcs and pulses that copy the jellied plankton’s swim, drawing curious gobies and cardinalfish within lunging range.



<h2 class="wp-block-heading" id="h-fastest-strikes-on-record">Fastest strikes on record</h2>



Once a victim lines up, the mouth opens twelve times wider than its resting size, pulling in water and prey through rapid <a href="https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/striated-frogfish/" target="_blank" rel="noreferrer noopener">suction feeding</a>. 



High‑speed videos have timed the attack at just six milliseconds, making the frogfish one of the quickest predators recorded.



That burst happens because elastic ligaments around the jaw store energy while the fish crouches. Releasing the latch snaps the head forward, creating a pressure wave that drags prey inward before the target knows it moved. 



The stomach then stretches like a balloon, letting a four‑inch frogfish swallow a meal almost twice its own length. Mouth, stomach, and even gill covers reset within minutes, ready for the next ambush without swimming far.



<h2 class="wp-block-heading" id="h-hairy-frogfish-lives-without-swimming">Hairy frogfish lives without swimming</h2>



Frogfish seldom swim, preferring a slow shuffle powered by limb‑like pectoral and pelvic fins. The gait looks clumsy, yet it lets the <a href="https://www.earth.com/news/world-frog-day-2025-protecting-natures-tiny-guardians/">animal</a> creep through branching corals or over sponges without stirring mud.



<a href="https://fishbase.se/summary/Antennarius-striatus.html" target="_blank" rel="noreferrer noopener">FishBase</a> records show the species from New Jersey to Brazil and across the Indo‑Pacific, at depths ranging from tide pools to 720 feet. 



Most adults settle below 100 feet where wave surge is gentle, but juveniles often lurk among shore grass beds that teem with shrimp.



Males change color during courtship, trailing females to the surface where a buoyant ribbon of up to 288,000 eggs drifts free. Larvae hatch in open water and later drop to the bottom, beginning the camouflage dance anew.



<h2 class="wp-block-heading" id="h-what-the-findings-mean">What the findings mean</h2>



“Aggressive mimicry allows a predator to masquerade as something harmless to approach prey,” wrote marine zoologist <a href="https://zoolstud.sinica.edu.tw/Journals/44.3/299.pdf" target="_blank" rel="noreferrer noopener">John E. Randall</a>. Aggressive mimicry, where a predator disguises itself as the prey’s food, shows up in a handful of reef hunters.&nbsp;



The fluorescent lure adds a light signal to that illusion, effective only for animals with visual pigments tuned to blue and green. Future lab tests will measure how often fish reject non‑fluorescent lures compared with glowing ones, refining ideas about sensory ecology.



Understanding these cues may also improve non‑invasive survey methods that use fluorescence to spot cryptic species on night dives. Conservation teams already trial blue‑light transects to count seahorses and pipefish that vanish under white lamps.



<h2 class="wp-block-heading" id="h-how-to-protect-hairy-frogfish">How to protect hairy frogfish</h2>



Antennarius striatus sits on the <a href="https://www.iucnredlist.org/species/16406979/115354869#assessment-information" target="_blank" rel="noreferrer noopener">IUCN list</a> as “Least Concern,” but habitat loss threatens local populations on polluted coasts. 



Collectors sometimes trawl adults for the aquarium trade, yet demand remains modest compared with bright reef staples like clownfish.



Protecting rubble fields and sea‑grass beds will likely benefit the frogfish alongside countless small invertebrates. Marine parks can also restrict night fishing with lights that might interfere with fluorescent signaling.



Citizen scientists armed with blue torches contribute valuable sightings through photo databases. Each image builds a map of occurrence, molt timing, and lure color that researchers can mine for long‑term trends.



The study is published in <a href="https://link.springer.com/article/10.1007/s00338-016-1493-1" target="_blank" rel="noreferrer noopener">Coral Reefs</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Strangest fish in the ocean walks on the seafloor, changes colors, and uses a fishing lure

The hairy frogfish looks more like a tuft of drifting...

Organs are not molded like blobs of passive clay. They rise from busy landscapes where cells crawl, tug, and signal until form emerges. 



In new work with the humble fruit <a href="https://www.earth.com/news/flies-are-more-vulnerable-to-climate-change-than-bees/">fly</a>, researchers watched future muscle cells roam across a juvenile testis, squeeze it like a drawstring bag, and twist the tissue into its adult spiral.



What they learned about this roaming workforce may also explain how tumors invade distant sites. 



Dr. Maik Bischoff of the <a href="https://www.unc.edu/" target="_blank" rel="noreferrer noopener">University of North Carolina</a> at Chapel Hill, together with colleagues in the <a href="https://tarheels.live/peiferlab/" target="_blank" rel="noreferrer noopener">Peifer Laboratory</a>, led the project and captured the shape‑shifting drama in living <a href="https://www.earth.com/news/earth-is-just-three-years-away-from-dangerous-carbon-milestone/">animals</a>.



<h2 class="wp-block-heading" id="h-fruit-fly-organs-shaped-by-muscle-cells">Fruit fly organs shaped by muscle cells</h2>



The fruit fly <a href="https://www.sciencedirect.com/topics/neuroscience/drosophila-melanogaster" target="_blank" rel="noreferrer noopener">Drosophila melanogaster</a> starts with a smooth, oval testis. Within hours, waves of <a href="https://www.sciencedirect.com/topics/engineering/mesenchymal-cell" target="_blank" rel="noreferrer noopener">mesenchymal cells</a> - motile precursors that resemble fibroblasts - glide over its surface.



These cells do not travel at random; they move as a sheet in a process known as <a href="https://journals.biologists.com/jcs/article/137/12/jcs261549/358091/perspectives-in-collective-cell-migration-moving" target="_blank" rel="noreferrer noopener">collective cell migration</a>. Coordination keeps gaps from forming and ensures every patch of the organ gets covered.



Most textbooks credit nearby <a href="https://my.clevelandclinic.org/health/articles/22062-epithelium" target="_blank" rel="noreferrer noopener">epithelial cells</a> with the heavy lifting of organ building, because epithelial sheets act like bricks and mortar. 



The new study shows that migratory peers can be just as important, especially when an organ must change length, curvature, or torsion.



Each <a href="https://www.science.org/doi/10.1126/sciadv.adu3741" target="_blank" rel="noreferrer noopener">precursor</a> advances roughly one body length every ten minutes, a pace that, scaled to human size, would equal a jog along a football field every hour.



<h2 class="wp-block-heading" id="h-cells-crawl-to-shape-the-fruit-fly-testis">Cells crawl to shape the fruit fly testis</h2>



“Trying to figure it out from static images is like learning the rules of basketball from a handful of screenshots,” said Bischoff. His team labeled the precursors with fluorescent markers and filmed them for six hours.



The videos of fruit fly organs forming revealed alternating bouts of advance and constriction: cells first crawled distally, then tightened the actin belt wrapped around the testis. 



To capture these speeds, the team used a spinning‑disk microscope paired with adaptive optics that collected volumetric stacks every 30 seconds without bleaching the tissue.



The group found that each precursor keeps at least three filopodia in contact with its neighbors, acting like fingers in a zip‑lock seam. When one cell stalled, the seam held firm and force propagated through the sheet, much like hikers roped together on ice. 



The choreography echoed <a href="https://www.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2023.1163583/full" target="_blank" rel="noreferrer noopener">computer models</a> showing that follower‑guided migration remains robust even when leaders falter.



<h2 class="wp-block-heading" id="h-fruit-fly-organs-and-nerve-signals">Fruit fly organs and nerve signals</h2>



Unexpectedly, the roving precursors spoke in the chemical language best known from neural development. The key messenger is <a href="https://www.sciencedirect.com/topics/neuroscience/semaphorin" target="_blank" rel="noreferrer noopener">semaphorin</a>, and its receptor <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/plexin" target="_blank" rel="noreferrer noopener">plexin</a> sits in the cell membrane acting as a brake and steering wheel at the same time. 



Biochemists often study the pair for their role in guiding axons, but the same duo now turns up in gonad shaping.



Genetic tricks showed that reducing plexin made testis‑wrapping cells clump together, while too much plexin caused them to drift apart. Either imbalance opened holes in the muscle coat. 



The effect mirrors work in vertebrates where <a href="https://pubmed.ncbi.nlm.nih.gov/39490515/" target="_blank" rel="noreferrer noopener">semaphorin‑plexin circuits</a> can either loosen or tighten junctions depending on context.



<h2 class="wp-block-heading" id="h-from-fruit-flies-to-mammals">From fruit flies to mammals</h2>



Intriguingly, fruit‑fly semaphorin‑1b seems to temper plexin rather than activate it, an antagonism that is echoed in mammalian <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11482903/" target="_blank" rel="noreferrer noopener">semaphorin‑6A</a> that fine‑tunes cortical neuron spacing. 



Downstream of plexin, the small <a href="https://www.nature.com/articles/cr2012110" target="_blank" rel="noreferrer noopener">GTPase R‑Ras2</a> flips between on and off states to regulate integrin‑mediated grip on the underlying matrix, a mechanism previously linked to blood vessel stability.



The fruit‑fly result hints that the same switchboard may tune adhesion in very different tissues.



<h2 class="wp-block-heading" id="h-how-cancer-cells-move">How cancer cells move</h2>



Cancer cells hijack developmental playbooks when they leave a primary tumor. They often assume a <a href="https://www.nature.com/articles/nri2395" target="_blank" rel="noreferrer noopener">mesenchymal</a> identity, migrate collectively, and "talk" through semaphorin‑plexin signals that were turned down after birth. 



A 2024 <a href="https://www.sciencedirect.com/science/article/abs/pii/S0024320523001339" target="_blank" rel="noreferrer noopener">review</a> cataloged over a dozen tumors in which plexin signaling correlated with invasion depth and metastatic load.



“Mesenchymal cells are often overlooked in organ development, but they’re incredibly dynamic and influential,” noted senior author Dr. Mark Peifer.



Because the <a href="https://pubmed.ncbi.nlm.nih.gov/21610676/" target="_blank" rel="noreferrer noopener">fly testis</a> is easy to image and manipulate, it offers a rare window into how normal migratory sheets avoid tearing. Tumor clusters face the same engineering problem when they travel through cramped extracellular spaces.&nbsp;



The team’s discovery that a neuron‑style guidance cue balances cohesion and flexibility could explain why <a href="https://www.nature.com/articles/s41598-025-91559-y" target="_blank" rel="noreferrer noopener">blocking</a> specific semaphorins slows breast cancer spread in mice. 



If the pathway keeps malignant cells together, disrupting it might splinter a cluster into cells too weak to survive alone.



<h2 class="wp-block-heading" id="h-fruit-flies-and-organ-development">Fruit flies and organ development </h2>



Beyond oncology, <a href="https://www.earth.com/news/dragonfly-larvae-expose-climates-hidden-influence-on-biology/">insights</a> from fruit flies add a control knob for future tissue‑engineering projects. Synthetic organoids usually rely on patterned growth factors and stiff scaffolds, yet they still collapse or fold unpredictably.



Tuning semaphorin or plexin activity could let bioengineers guide cell streams to carve channels, chambers, or helical shells without external molds. 



Pharmaceutical firms already test small‑molecule plexin inhibitors for neuropathic pain; the same toolbox now has potential in regenerative medicine if dosing can be localized.



The approach may also help repair injuries in adults. <a href="https://pubs.acs.org/doi/10.1021/acsbiomaterials.2c00039" target="_blank" rel="noreferrer noopener">Endothelial sheets</a> that line blood vessels regenerate by collective migration, and aberrant R‑Ras signaling is tied to leaky capillaries in diabetes. 



Insights from fruit fly organ development could point to drug targets that restore vessel integrity after trauma or stroke.



<h2 class="wp-block-heading" id="h-building-transplant-ready-tissues">Building transplant-ready tissues</h2>



Finally, Bischoff’s high‑speed imaging of fruit flies, which records thousands of cell paths in deep tissue, sets a new standard for studying morphogenesis. 



Combining it with optogenetic switches that toggle plexin within seconds might reveal how transient pulses of adhesion control long‑term shape.



 Such precision will be essential for building transplant‑ready tissues where every curve counts.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/sciadv.adu3741" target="_blank" rel="noreferrer noopener">Science Advances</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Muscle cells crawl across fruit fly organs to build body structures

Organs are not molded like blobs of passive clay. They...

A hidden camera at Richard Underwood Nature Refuge in southwest Queensland has captured an unlikely scuffle: a juvenile northern hairy‑nosed wombat spun in circles while a short‑beaked echidna trundled past, seemingly unfazed. 



The playful yet tense scene, buried among 100 hours of footage, is more than viral bait, explains Andy Howe of the <a href="https://www.australianwildlife.org/" target="_blank" rel="noreferrer noopener">Australian Wildlife Conservancy</a>.



<h2 class="wp-block-heading" id="h-shy-wombat-steps-into-the-light">Shy wombat steps into the light</h2>



Only around 400 <a href="https://www.qld.gov.au/environment/plants-animals/conservation/threatened-species/featured-projects/northern-hairy-nosed-wombat2" target="_blank" rel="noreferrer noopener">northern hairy‑nosed wombats</a> remain after decades of painstaking work to reverse their decline.



“It’s very gratifying to know that one of the world’s most critically endangered animals is doing well and breeding within the safety of the fenced area,” said Howe, recalling that numbers bottomed out at just 35 animals in the late 1990s.



The joey’s smooth coat and sturdy build suggest plentiful forage and low stress, two metrics ecologists rarely get to confirm in the field. 



Because the <a href="https://www.earth.com/news/endangered-species-act-faces-its-biggest-legal-shift-in-decades/">species</a> is nocturnal and wary, every clear daylight image helps researchers refine population models and track body condition.



<h2 class="wp-block-heading" id="h-why-a-spiky-passerby-stayed-calm">Why a spiky passerby stayed calm</h2>



The echidna, one of only five egg‑laying mammals or monotremes, carried on as if nothing happened. 



<a href="https://www.earth.com/news/monotremes-platypus-and-echidnas-break-mammal-rules-with-weird-sex-system/">Echidnas</a> deter attackers by erecting sharp spines and, when pressed, curling into a compact ball that exposes only hardened quills, a textbook defense noted by zoologists.



“It’s a nervous wombat and a happy echidna,” joked biologist <a href="https://australian.museum/about/history/exhibitions/trailblazers/tim-flannery/" target="_blank" rel="noreferrer noopener">Tim Flannery</a> of the <a href="https://australian.museum/" target="_blank" rel="noreferrer noopener">Australian Museum</a> after watching the clip.



<h2 class="wp-block-heading" id="h-digging-for-survival">Digging for survival</h2>



The northern hairy‑nosed wombat is the largest burrowing <a href="https://www.earth.com/news/worlds-rarest-marsupial-is-fighting-for-survival-again/">marsupial</a>, stretching to a yard in length and weighing up to 77 pounds, with some individuals living three decades in the wild. 



Its barrel‑shaped body, forward‑facing pouch, and chisel‑like claws turn sandy soils into elaborate tunnel networks that buffer heat and predators.



Inside those networks the animals conserve water, ride out droughts, and minimize energy loss, emerging only at night to graze on native grasses. 



Because females raise a single joey no more than every two years, each new youngster represents a sizeable share of future genetic diversity.



<h2 class="wp-block-heading" id="h-betting-on-new-homes">Betting on new homes</h2>



In 2009 conservationists launched an ambitious translocation, moving 15 wombats into the 320‑acre <a href="https://www.australianwildlife.org/sanctuaries/richard-underwood-nature-refuge" target="_blank" rel="noreferrer noopener">Richard Underwood refuge</a> behind predator‑proof fencing. 



Fifteen years on, at least the same number now live there as residents rather than transplants, and the latest juvenile shows that second‑generation wombats are thriving without human hand‑feeding.



Camera traps, set low along open runways, let ecologists confirm pouch emergence dates, monitor health, and detect any intruding wild dogs before disaster strikes. 



Success at this site has revived plans for a third population farther west, reducing the risk that fire, disease, or floods could wipe out the species in a single blow.



<h2 class="wp-block-heading" id="h-why-wombats-like-burrows">Why wombats like burrows</h2>



Wombats earn the label ecosystem engineer because their 300‑foot‑long burrows moderate temperature and humidity for many smaller animals; “burrows are essential for regulating underground temperature and humidity,” noted <a href="https://www.researchgate.net/scientific-contributions/David-D-Harper-12634637" target="_blank" rel="noreferrer noopener">Dave Harper</a> of Queensland’s threatened species unit.



Researchers have since <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11285166/" target="_blank" rel="noreferrer noopener">documented</a> reptiles, small birds, and even introduced mammals using wombat tunnels as wildfire refuges and drought shelters. 



By churning sub‑soil to the surface the animals also aerate compacted ground and accelerate nutrient cycling, boosting grass growth for grazers that share their range.



Conservationists argue that restoring wombats across their former territories could amplify these soil benefits while giving embattled <a href="https://www.earth.com/news/new-dumbo-octopus-species-carnarvon-flapjack-discovered-in-very-deep-ocean-waters/">species new</a> hideouts during Australia’s increasingly severe heatwaves.



<h2 class="wp-block-heading" id="h-conserving-charisma-free-species">Conserving charisma‑free species</h2>



Northern hairy‑nosed wombats lack the global fame of <a href="https://www.earth.com/news/koalas-in-queensland-show-signs-of-immunity-to-deadly-retrovirus/">koalas</a>, yet their story shows how science, rural landholders, and careful media moments can rally support. 



Every fresh glimpse of a healthy joey, especially one tossing dirt at an indifferent <a href="https://www.earth.com/news/bizarre-egg-laying-mammal-rediscovered-in-the-cyclops-mountains/">echidna</a>, helps translate spreadsheets of recovery targets into an image ordinary people remember.



<figure class="wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio"><div class="wp-block-embed__wrapper">
https://youtu.be/me3iPRM28hk?si=qLxqyEJerkXBP6Uv
</div><figcaption class="wp-element-caption">Ecologists at Australian Wildlife Conservancy (AWC) were ecstatic when they captured rare footage of a critically endangered, juvenile Northern Hairy-nosed Wombat strolling around Richard Underwood Nature Refuge (RUNR) in south-west Queensland. With only 400 individuals remaining in the world, every single wombat sighting counts.</figcaption></figure>



Long term, the program still hinges on predator control, genetic monitoring, and enough grassy habitat to feed expanding colonies, but small wins on trail cameras keep field teams motivated. 



If additional safe sites come online before the next severe drought, researchers believe the population can pass the 500‑animal threshold that lowers extinction risk.



<h2 class="wp-block-heading" id="h-wombats-are-quickly-disappearing">Wombats are quickly disappearing</h2>



Before Europeans arrived, northern hairy‑nosed wombats ranged from central Queensland down into New South Wales and northern Victoria. 



But widespread land clearing for sheep and cattle grazing destroyed much of the open woodland they relied on for <a href="https://www.earth.com/earthpedia-articles/wombats-and-the-mystery-of-cubed-poop/">food and shelter</a>.



They were also directly targeted. In 1884, over a thousand wombats were shot on a single property in the Riverina region. 



Habitat loss, competition with livestock, and predation by dingoes and wild dogs pushed the species to the brink by the 1980s.



The images used for this news item have been taken from the<a href="https://www.australianwildlife.org/" target="_blank" rel="noreferrer noopener"> Australian Wildlife Conservancy</a> channel.



-----



Like what you read?<a href="https://www.earth.com/subscribe/"> Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on<a href="https://www.earth.com/earthsnap/"> EarthSnap</a>, a free app brought to you by<a href="https://www.earth.com/author/eralls/"> Eric Ralls</a> and Earth.com.



-----

Camera captures video showing one of Australia's rarest and strangest mammals

A hidden camera at Richard Underwood Nature Refuge in southwest...

Mammals usually avoid sour flavors, but a robin can devour berries so tart they would make most of us pucker in pain. How do birds pull off this dietary feat?



A new study answers the riddle by showing that evolution has rewired birds' sour-taste machinery. 



The discovery not only reveals why avian diners relish fruits with pH values as low as lemon juice, it also hints that a molecular tweak in taste may have opened new ecological doors during <a href="https://www.earth.com/news/bird-evolution-timeline-pushed-back-20-million-years-by-baminornis-zhenghensis-discovery/">bird evolution</a>.



<h2 class="wp-block-heading" id="h-the-sour-switch-in-birds">The sour switch in birds</h2>



To decode avian acid tolerance, scientists at the <a href="http://english.kiz.cas.cn/">Kunming Institute of Zoology</a>, the <a href="https://english.cas.cn/">Chinese Academy of Sciences</a>, and the <a href="https://www.bi.mpg.de/en">Max Planck Institute for Biological Intelligence</a> focused on OTOP1. It is the only known vertebrate receptor that detects <a href="https://www.earth.com/news/a-surprising-amount-of-adults-like-intensely-sour-flavors/">sour flavors</a>.



In mammals - including people - OTOP1 channels fire vigorously when acidity rises, sending a sharp warning to the brain. 



In many birds, however, OTOP1 does the opposite: as the surrounding fluid turns more acidic, the channel shuts down. With the bitter alarm silenced, beaks keep munching.



The team began by cataloging bird feeding habits across Asia, Europe, and South America. The data confirmed that many songbirds, pigeons, and parrots thrive on fruits whose pH dips below 3 - a level similar to vinegar.



<h2 class="wp-block-heading" id="h-genes-that-change-taste">Genes that change taste</h2>



Genetic sequencing of their taste receptors revealed a cluster of four amino acid changes - H239, L306, H314, and G378 - that alter how the OTOP1 protein behaves under acid stress.



Functional tests delivered the clincher. When researchers used <a href="https://www.earth.com/news/crispr-used-to-remove-extra-chromosomes-in-down-syndrome-and-restore-cell-function/">CRISPR</a> to edit these mutations into the OTOP1 gene of laboratory mice, the rodents’ brain cells fired far less in response to sour liquids.



Conversely, when they blocked OTOP1 in pigeons and canaries with a targeted inhibitor, the birds promptly abandoned their usual acidic fare. The receptor is therefore both necessary and sufficient for avian acid tolerance.



<h2 class="wp-block-heading" id="h-sour-and-sweet-together">Sour and sweet together</h2>



Tracing the family tree of OTOP1 revealed another twist. The last of the four mutations - G378 - arose only in songbirds, a lineage that today accounts for nearly half of all living bird species.



The timing is suggestive. Earlier work had shown that <a href="https://www.earth.com/news/songbirds-benefit-from-social-networks-during-migration/">songbirds</a> also gained a sweet-taste receptor not found in most other birds. 



The new study raises the possibility that upgrades in both sour suppression and sweet perception co-evolved, enabling ancestral songbirds to exploit nectar and acidic fruit simultaneously. That ecological flexibility might help explain the group’s modern success.



<h2 class="wp-block-heading" id="h-big-impacts-from-taste">Big impacts from taste</h2>



Why should anyone beyond ornithology circles care about a bird’s taste tolerance? For one, the findings illuminate how sensory systems evolve under dietary pressures.



Sour taste originally signaled unsafe or unripe food. Turning that alarm off required a molecular workaround - achieved with just a handful of amino acid swaps. This shows how rapidly chemosensory genes can reshape animal behavior and niche use.



There are broader ecosystem implications too. Birds that devour harshly acidic fruits are pivotal <a href="https://www.earth.com/news/insects-play-a-much-bigger-role-in-seed-dispersal-than-we-thought/">seed dispersers</a> in many tropical forests. Birds ability to stomach such fare ensures that plant species with defensive sour pulp still find willing couriers.



Understanding the molecular roots of that partnership refines predictions about how changing climates or fruit chemistry could cascade through food webs.



<h2 class="wp-block-heading" id="h-a-blueprint-for-taste">A blueprint for taste</h2>



The study also provides a roadmap for probing taste evolution in other animals. Similar OTOP1 edits might help explain why some primates relish citrus while others avoid it, or why certain fish tolerate acidic streams. 



Meanwhile, the CRISPR-mouse model offers a living platform to test how sour aversion shapes diet, metabolism, and health.



For agricultural science, the insights could guide breeding of poultry or songbird populations used in pest control, tailoring feed formulations to their altered taste sensitivities. 



Plant biologists might likewise engineer fruit acidity to attract or deter specific avian consumers.



<h2 class="wp-block-heading" id="h-taste-and-bird-evolution">Taste and bird evolution</h2>



Birds captivated biologists with their songs, colors, and aerial exploits. Now, thanks to a little proton-gated channel in the <a href="https://www.earth.com/news/electronic-tongue-could-revolutionize-food-safety/">tongue</a>, they have added another evolutionary marvel: an internal dial that mutes the sting of acid.



Researchers found that tweaks to sour taste may have co-evolved with sweetness, reshaping how birds sense and seek food. Together, these changes helped propel birds into ecological niches overflowing with nectar and tangy fruit.



The work highlights a recurring theme in evolutionary biology: subtle molecular changes can yield sweeping macro-scale outcomes. 



A quartet of amino acid substitutions may sound trivial, yet it probably influenced what early songbirds ate, where they migrated, and how they diversified.



The next time you watch a thrush gulp down a crabapple or a tanager feast on still-green berries, remember their dauntless palate is the legacy of eons of microscopic tinkering. That subtle adaptation continues to shape forests and fields around the globe.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/science.adr7946">Science</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Why birds have an unusual appetite for sour foods

Mammals usually avoid sour flavors, but a robin can devour...

Marine pollution usually conjures images of oil slicks and plastic waste, but a new study shifts the focus from visible pollutants to the invisible metals and toxins that have infiltrated every ounce of water in our oceans. 



Researchers examining stranded dolphins on the southeastern coast of Brazil discovered that unborn calves already carry a cocktail of metals absorbed from their mothers’ <a href="https://www.earth.com/news/national-dolphin-day-2025-honoring-the-oceans-most-playful-minds/">bodies</a>.



The tissues of two dolphin species found stranded on the Brazilian coast over the period of a year were analyzed. 



Samples were taken from stranded Guiana dolphins (<a href="https://us.whales.org/whales-dolphins/species-guide/guiana-dolphin/" target="_blank" rel="noreferrer noopener">Sotalia guianensis</a>), as well as from franciscana dolphins (<a href="https://nmmf.org/marine-mammal/franciscana-dolphin/" target="_blank" rel="noreferrer noopener">Pontoporia blainvillei</a>).



The franciscana dolphin, also known as the La Plata dolphin, is a species of river dolphin that is endemic to the Southwestern Atlantic and is critically endangered. 



One unborn calf of a franciscana dolphin was also sampled in order to identify whether toxic metals cross the placenta.



<h2 class="wp-block-heading" id="h-metals-cross-the-placenta-in-dolphin-calves">Metals cross the placenta in dolphin calves </h2>



The team detected copper, zinc, arsenic, vanadium, and mercury in the fetus recovered from the pregnant franciscana dolphin.  



“This is direct evidence of <a href="https://www.sciencedirect.com/science/article/abs/pii/S0048969721023585" target="_blank" rel="noreferrer noopener">transplacental transfer</a>,” stated Guilherme dos Santos Lima, a doctoral researcher at <a href="https://www.international.unesp.br/" target="_blank" rel="noreferrer noopener">São Paulo State University</a> and first author of the work.



The one‑year monitoring data showed higher average levels of cadmium, mercury, and molybdenum in older calves, indicating that, although calves are first exposed to these metals while in utero, there is progressive <a href="https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/bioaccumulation" target="_blank" rel="noreferrer noopener">bioaccumulation</a> in the bodies of individuals as they age.



Earlier <a href="https://www.researchgate.net/publication/230616951_Mercury-Selenium_Relationships_in_Liver_of_Guiana_Dolphin_The_Possible_Role_of_Kupffer_Cells_in_the_Detoxification_Process_by_Tiemannite_Formation" target="_blank" rel="noreferrer noopener">investigations</a> of Guiana dolphin mother–fetus pairs in neighboring regions found mercury transfer ratios as high as 0.19, confirming the placenta is no barrier to certain <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC3409158/" target="_blank" rel="noreferrer noopener">heavy metals</a>. 



Those metals can disrupt enzyme systems and neuronal development long before an animal even takes its first breath.



Franciscana populations are already shrinking because of gill‑net by‑catch and habitat loss. Adding in‑utero exposure to contaminants increases the odds of developmental <a href="https://www.earth.com/news/how-dolphin-brains-evolved-to-see-underwater-by-using-sound-echolocation/">problems</a> that could lower survival rates.



<h2 class="wp-block-heading" id="h-dolphins-are-sentinel-species">Dolphins are sentinel species</h2>



Cetaceans breathe air, nurse their young, and feed high on the food web. Their long lifespans and coastal habits make them ideal sentinels of ocean health. 



When scientists track toxin loads in dolphins, they gain a time‑averaged snapshot of everything moving through the local food chain.



<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC5644643/" target="_blank" rel="noreferrer noopener">Atlantic bottlenose dolphins</a>, for instance, helped researchers link mercury‑laden fish to neurodevelopmental delays in children who ate similar seafood. 



The same “one health” logic applies in Brazil: what harms a calf tethered to its mother by an umbilical cord could also harm communities that rely on coastal fisheries.



Lima’s group worked with Brazil’s long‑term <a href="https://www.sciencedirect.com/science/article/abs/pii/S0025326X23012821" target="_blank" rel="noreferrer noopener">Beach Monitoring Project</a>, turning what would have been simple necropsies into an eight‑year contaminant record. Their approach echoes global calls for integrating wildlife toxicology with public‑health surveillance.



<h2 class="wp-block-heading" id="h-unborn-dolphin-carried-high-levels-of-metals">Unborn dolphin carried high levels of metals</h2>



Copper and zinc are essential for growth, yet the fetal liver carried them at roughly five times the mother’s concentration, implying active transport across the placenta. 



By contrast, cadmium and mercury rose steadily with age, matching classical patterns of dietary uptake.



Laboratory <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC11274124/" target="_blank" rel="noreferrer noopener">data</a> show that mercury can interfere with dolphin immune cells and cause hepatic damage at sub‑lethal doses.



Vanadium’s presence surprised the team because few marine‑mammal studies report it. Though needed only in trace amounts, prenatal vanadium exposure in humans has been <a href="https://www.figo.org/resources/figo-statements/toxic-chemicals-and-environmental-contaminants-prenatal-vitamins" target="_blank" rel="noreferrer noopener">linked</a> to lower birth weights and preterm delivery. 



Detecting the metal in a dolphin <a href="https://www.earth.com/news/dolphins-face-serious-threats-from-chemical-pollution-and-ocean-warming/">fetus</a> suggests an unexplored risk pathway in marine food webs.



Spatial analysis showed little difference among the three São Paulo sub‑regions, indicating that ocean currents disperse effluents broadly along the 370‑mile (595-kilometer) stretch of coast. 



Only cadmium spiked in Guiana dolphins from the industrialized southern sector, a finding that is consistent with local phosphate‑fertilizer discharge records.



<h2 class="wp-block-heading" id="h-shared-risks-and-next-steps">Shared risks and next steps</h2>



“The detection of metals in fetuses is not just a conservation red flag, but a potential indicator of broader ecosystem disruption,” noted Lima. 



Regulators could use such fetal markers as early‑warning signals, much as amphibian deformities once forecast pesticide problems on land.



For conservationists, the results argue for stricter catch limits on franciscana dolphins, and targeted cleanup of heavy‑industry outfalls. 



For scientists, they open questions about how mixed‑metal exposure interacts with other stressors such as warming seas and ship noise.



Several countries already track persistent organic pollutants in pinnipeds; incorporating trace metals in cetacean monitoring would complete the chemical picture. 



Long‑term health studies, including hormone assays and immune‑function tests, could reveal whether today’s metal burdens are likely to translate into tomorrow’s reproductive failures.



<h2 class="wp-block-heading" id="h-metals-harm-dolphins-before-birth">Metals harm dolphins before birth</h2>



Recent conservation efforts often focus on visible threats like entanglement, overfishing, and habitat degradation. However, the presence of contaminants in unborn <a href="https://www.earth.com/news/dolphins-hear-special-whistles-and-change-their-behavior/">dolphins</a> adds a new layer of urgency to these strategies. 



Without addressing chemical exposures during critical developmental windows, rehabilitation or population recovery plans may fall short.



Scientists studying other marine mammals have found that early exposure to pollutants can compromise neurological development, immune function, and growth rates. 



If dolphin calves and the offspring of other marine mammals are already burdened with toxic elements before birth, they ultimately face higher mortality and lower fitness, regardless of protections offered later in life.



The study is published in <a href="https://www.sciencedirect.com/science/article/abs/pii/S0048969724050034" target="_blank" rel="noreferrer noopener">Science of The Total Environment</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Unborn dolphin calves have toxic metals in their blood, revealing horrific ocean pollution

Marine pollution usually conjures images of oil slicks and plastic...

Pets can’t tell you when they’re too hot, dizzy, or nauseous - or when something just feels off. As summer heats up, it’s up to you to recognize the signs and act fast if your pet shows symptoms of heatstroke.



Heatstroke is a medical emergency. It occurs when a pet's body overheats and is unable to cool down on itself. If you even suspect your pet may have it, you need to get in touch with your usual vet or an emergency animal health service immediately.



Researchers have been studying the <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC5800390/">impacts of heatstroke</a> on animals, and their conclusions are definite: heatstroke can harm just about every system in your pet's body.



<h2 class="wp-block-heading" id="h-what-exactly-is-heatstroke">What exactly is heatstroke?</h2>



Heatstroke occurs when your dog's body temperature gets too high - over 105.8°F. This may be caused by heat, lack of ventilation, excessive exercise, or being left inside a hot area such as a car or garage.



Some of the earliest symptoms of heatstroke are excessive drooling, heavy panting, and vomiting or dry heaving. You may find that your pet's body is unusually hot, particularly around the head. 



They may begin to stumble, move in an uncoordinated manner, or collapse. In more severe cases, <a href="https://www.earth.com/news/dogs-detect-epileptic-seizures/">seizures</a> can happen, and some animals become unable to stand or walk at all.



If untreated, that the elevated temperature starts to disrupt essential functions such as circulation and digestion. It can spiral rapidly into organ damage - impacting the liver, kidneys, and digestive system - and can result in coma or death if left unaddressed in a timely manner.



<h2 class="wp-block-heading" id="h-act-fast-don-t-wait">Act fast, don't wait</h2>



Start by getting your pet out of the heat. Bring them inside or move them to a shady area. Then, get them to a veterinarian immediately. Every second counts.



While preparing to leave, you can begin to gently cool them down. Wet towels with room temperature or cool (not cold) water and place them over your pet’s head and body. 



Keep air circulating by placing them in front of a fan or under air conditioning if available. The goal is to gradually reduce their temperature - not to shock the system.



Do not let active cooling efforts delay travel to your nearest veterinary support. Never submerge your pet in ice or cold water, as this can lead to shock.



<h2 class="wp-block-heading" id="h-how-vets-treat-heatstroke">How vets treat heatstroke</h2>



Once at the clinic, your vet will assess the situation and begin treatment right away. In many cases, they will administer oxygen and start actively cooling the pet. 



They may provide fluids either intravenously or under the skin, depending on the severity of dehydration.



Some pets need medications to support their heart or gastrointestinal function. Vets will also run lab work to evaluate internal damage and may need to hospitalize the animal for monitoring and recovery.



<h2 class="wp-block-heading" id="h-how-pets-get-heatstroke">How pets get heatstroke</h2>



Heatstroke doesn’t necessarily occur in extreme situations. It’s usually a result of a combination of heat, <a href="https://www.earth.com/news/humidity-increases-urban-heat-stress/">humidity</a>, poor ventilation, and insufficient shade or access to drinking water. 



Cars are particularly perilous - even when the weather is not hot. The temperature in a parked car can quickly rise, making it a deadly trap.



Even though <a href="https://www.earth.com/news/expert-tips-how-to-keep-your-dog-safe-from-heatstroke-this-summer/">dogs</a> are more commonly afflicted, cats are also vulnerable. Cats don’t cool themselves with panting like dogs, so when they begin to pant, it means they're in distress. Stress or heat might be the reason.



Some animals are more susceptible than others. Short-snouted dogs - such as <a href="https://www.earth.com/news/english-bulldogs-are-suffering-from-poor-breeding-practices/">bulldogs</a> or pugs - will usually struggle more with body temperature control. Thickly coated pets, higher-weight pets, or pets who aren’t accustomed to warm temperatures are also at increased risk.



In a few situations, exertional heatstroke can occur in dogs from exercise, even on a cool day, if they have not acclimatized to the heat.



<h2 class="wp-block-heading" id="h-prevention-starts-with-you">Prevention starts with you</h2>



Prevention of heatstroke is the simplest way to guard your pet. Always ensure your pet can get to shade and loads of fresh water if outside. Never leave them in a parked car for even a few minutes. 



If you’re walking your dog, try to do so early in the morning or later in the evening when the sun is less intense. When the weather is warm, keep things physically light and try to stay away from heavy exercise, particularly with pets that are most susceptible.



Our pets rely on us to protect them. Understanding how heatstroke occurs, how to recognize it, and what to do can be the difference between life and death.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

What every pet owner needs to know about heatstroke

Pets can’t tell you when they’re too hot, dizzy, or...

As Earth’s temperature rises, nature begins to shift. Butterflies, along with many animals and plants, now move north into places that were once too cold. Scientists are closely watching this trend to see how evolution shapes these movements - and where it might fall short.



A new study focuses on wall brown butterflies, which offer big clues about the role of evolution in climate-driven movement. Researchers wanted to know how much change the species could manage on its own



The research reveals that while evolution helps, it has its limits. Temperature remains a gatekeeper, keeping some places off-limits despite warming trends.



<h2 class="wp-block-heading" id="h-butterflies-adapt-as-they-move-north">Butterflies adapt as they move north</h2>



The wall brown (Lasiommata megera) is a grassland <a href="https://www.earth.com/news/butterfly-hovering-technique-could-revolutionize-drone-design/">butterfly</a> found across Europe. In recent decades, it has become more common in parts of Scandinavia. Yet it has declined sharply in Western Europe. 



The butterfly's success in the north is not random. It has changed its life cycle to suit longer days and different seasonal patterns.



Mats Ittonen is one of the lead authors of the study, which was conducted by researchers in the Department of Zoology at <a href="https://www.su.se/english/education">Stockholm University</a>.



“Our results show that even though the butterflies adapt their life cycle as they move northwards, there are limits that evolution cannot easily overcome,” said Ittonen. 



Evolution seems to help the species match new environments. In particular, it allows the butterfly to respond to cues that remain steady, like the number of daylight hours. 



These cues are important because they guide dormancy and development. Still, not everything can change easily. Winters in northern regions continue to block further movement.



<h2 class="wp-block-heading" id="h-does-evolution-help-butterflies-survive">Does evolution help butterflies survive?</h2>



To explore how the wall brown has changed over time, the researchers carried out detailed field experiments. They collected butterflies from both southern and northern parts of Sweden.



The southern group came from Skåne county. The northern group came from Södermanland and Uppland counties. Then, they placed the butterflies in cages in three places: Skåne, Södermanland, and southern Dalarna.



The goal was to see how each group fared when exposed to identical environmental conditions. 



Dalarna sits just beyond the <a href="https://www.earth.com/news/national-learn-about-butterflies-day-an-enchanting-world-awaits/">species</a>’ current northern range. If butterflies from northern populations could survive there, it would suggest they had evolved better survival traits. The study looked at growth rate, timing of winter dormancy, and survival through the cold months.



“We wanted to know whether traits like faster growth, properly timed winter dormancy, and improved winter survival have evolved in northern butterflies, traits that could help them establish even further north,” said Professor Karl Gotthard.



<h2 class="wp-block-heading" id="h-evolution-improved-some-butterfly-traits">Evolution improved some butterfly traits</h2>



The findings showed that northern caterpillars did indeed grow faster. Summers are shorter in higher latitudes, so a quicker life cycle helps. They also entered dormancy at the right time. 



But these advantages did not translate into long-term survival. When winter came, the caterpillars in Dalarna struggled. Most did not make it.



The researchers concluded that even though evolution had helped improve some of the butterfly's traits, it had not yet solved the problem of cold resistance. 



Insects need more than just good timing and growth to thrive through northern winters. Without <a href="https://www.earth.com/news/butterfly-migration-habits-are-not-determined-by-their-dna/">traits</a> that guard against extreme cold, they simply cannot expand further.



“These kinds of limits are important to recognize if we want to predict how far north other species, including pests and disease vectors, will be able to move in a future climate,” said Professor Gotthard.



<h2 class="wp-block-heading" id="h-the-reality-of-environmental-pressures">The reality of environmental pressures</h2>



This study reveals something important about climate adaptation. Evolution can move quickly in insects, but it doesn’t always improve the right traits. 



Speed and timing matter, but without the ability to survive freezing temperatures, further expansion becomes impossible. Warmer summers help, but they do not guarantee success unless winters also become milder.



The butterflies serve as a reminder that not all environmental pressures can be overcome easily. Natural selection works with what’s available. 



If key genes for cold tolerance are rare or slow to spread, progress will stall. That seems to be the case with the wall brown butterfly. It has changed, but not enough.



<h2 class="wp-block-heading" id="h-what-this-means-for-other-species">What this means for other species</h2>



Many insect species have shifted their ranges in the past few decades. Sweden, in particular, has seen a steady rise in insect diversity further north. But each species carries its own set of traits and limits. What works for one may not work for another.



“The wall brown is far from alone. Many other insect species have also expanded northward over the past few decades, both in Sweden and elsewhere," said Ittonen.



"Understanding both which traits evolve and which ones actually set the limits for where species can live is essential for predicting the future of ecosystems and biodiversity in a warming world."



If winters remain harsh, many species will hit similar boundaries. Their success will depend not just on temperature trends, but on how fast and in what direction evolution works. 



Predicting this will require close studies like this one, where fieldwork meets biology to trace nature’s next move.



<h2 class="wp-block-heading" id="h-watching-the-edges-of-change">Watching the edges of change</h2>



The story of evolution in wall brown butterflies shows how nature reacts to climate change in small, careful steps. Evolution offers a path forward, but it is not a magic key. Cold winters still act as a wall. 



As climate change continues, scientists must ask not only if species can adapt, but whether those adaptations come in time.



For the wall brown and many others, survival at the edge depends not just on warming trends but also on biological timing, hidden traits, and chance. 



The cold sets a limit. And evolution, though powerful, sometimes stops short of breaking through.



The study is published in the journal <a href="https://www.pnas.org/doi/10.1073/pnas.2418392122" target="_blank" rel="noreferrer noopener">Proceedings of the National Academy of Sciences</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Butterflies can adapt quickly - but evolution has its limits

As Earth’s temperature rises, nature begins to shift. Butterflies, along...

For centuries, scientists have tried to understand how sharks and other animals grow and function as they increase in size. 



At the heart of this inquiry lies a simple geometric principle: surface area grows more slowly than volume. The "two-thirds scaling law" captures this relationship, suggesting that surface area scales with volume to the power of 2/3. 



While the idea is elegant, proving it in large, complex animals like sharks has been a challenge.



Now, a new study led by researchers from James Cook University (JCU) and the <a href="https://www.umass.edu" target="_blank" rel="noreferrer noopener">University of Massachusetts</a> offers compelling proof that this rule holds true for one of the most diverse and ancient animal groups on the planet - sharks. 



<h2 class="wp-block-heading" id="h-sharks-grow-by-the-rules">Sharks grow by the rules</h2>



Using digital models of 54 shark species, the team uncovered remarkable consistency in how these animals scale in size. Their work not only strengthens a foundational principle in biology but also reveals hidden constraints that may shape evolution itself.



“We found that sharks follow what's known as the 'two-thirds scaling law' almost perfectly,” said Joel Gayford, lead author and PhD candidate at <a href="https://www.jcu.edu.au" target="_blank" rel="noreferrer noopener">JCU</a>.



This means that as the body of a shark gets larger, the surface area increases in a predictable way based on their volume.



<h2 class="wp-block-heading" id="h-3d-models-map-the-shark-s-body">3D models map the shark's body</h2>



The team created high-resolution 3D meshes from CT scans and photogrammetry of museum specimens. The models were cleaned and processed in Blender software to remove distortions caused by preservation. Surface area and volume were measured digitally for accuracy.



The sample ranged from the tiny&nbsp;Euprotomicrus bispinatus&nbsp;to the massive&nbsp;Rhincodon typus, the whale shark. Across these, the team observed nearly perfect adherence to the expected geometric rule. 



They scaled every <a href="https://www.earth.com/news/prehistoric-sea-monster-shark-fossils-found-in-worlds-largest-cave-325-million-years/">species</a> to the same body length (500 cm) and still found minimal differences in surface area and volume. This step removed body length as a confounding factor.



<h2 class="wp-block-heading" id="h-shark-scaling-stays-consistent">Shark scaling stays consistent</h2>



The study grouped sharks by habitat - pelagic, <a href="https://www.earth.com/news/nearly-two-thirds-of-coral-reef-sharks-and-rays-face-extinction/">reef-associated</a>, demersal, and others. Most showed near-identical surface area-to-volume relationships. 



Only reef-associated sharks showed minor deviation, with a scaling exponent of 0.60. Pelagic sharks matched the theoretical 0.66 almost exactly.



The team also accounted for evolutionary history using phylogenetic generalized least squares (PGLS) analysis. This ensured close relatives did not skew the results. Even after this, the average scaling value was just 0.64, only 3% off from 0.66.



<h2 class="wp-block-heading" id="h-biology-restricts-growth">Biology restricts growth</h2>



“This ratio is fundamental,” said Professor Jodie Rummer. “It underpins how animals breathe, regulate temperature, and process waste.” The near-perfect fit hints at deep-rooted evolutionary and developmental constraints.



Developmental limitations may prevent major changes in tissue distribution. Altering body geometry early in development is likely energy-intensive.



“Changing the way tissue is distributed throughout the body might require major changes during early embryonic development, and that's expensive, energetically speaking,” said Gayford.



<h2 class="wp-block-heading" id="h-why-shape-stills-matters">Why shape stills matters</h2>



The two-thirds law is not just theoretical. It supports models predicting how <a href="https://www.earth.com/news/sharks-may-benefit-from-rising-temperatures-but-not-from-rising-co2/">animals</a> regulate heat, absorb oxygen, or respond to climate change. 



“Surface area-to-volume ratios are key inputs in equations used to model how animals respond to climate change,” said Gayford. These equations can now be applied with greater confidence to sharks and other large animals.



The authors also observed that surface area in sharks did not follow phylogenetic patterns as strongly as volume did. This suggests that surface area may be more flexible but still constrained by developmental factors.



<h2 class="wp-block-heading" id="h-shark-body-follows-deep-biology">Shark body follows deep biology</h2>



Despite massive variation in shark ecology and movement, some are sluggish bottom-dwellers and others fast-swimming predators, their surface-to-volume relationships stay constant. 



Even differences in shape and lifestyle do not seem to change the rule. That consistency points to deeper biological limits rather than ecological demands.



This study adds weight to the idea that body design follows strict physical and developmental rules. It also shows how new tools like <a href="https://www.earth.com/news/largest-ever-3d-map-of-human-brain-created-by-harvard-and-google/">3D imaging</a> can answer long-standing questions in biology. 



Although researchers still need to explore the energy costs of body shape changes, this study lays a strong foundation.



Sharks obey the geometry of life, their body surfaces grow in lockstep with volume in a way that supports a basic biological law. The rule holds true across shape, size, and ecological function.



That’s a rare kind of simplicity in biology and one that might apply far beyond sharks.



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rsos.242205" target="_blank" rel="noreferrer noopener">Royal Society Open Science</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

How the shark's body grows with geometric precision

For centuries, scientists have tried to understand how sharks and...

In 1859, Darwin proposed that evolution worked slowly - even for creatures like the worm. Tiny changes, stacked over time, led species to gradually become something new.



But even he had to admit the fossil record didn’t back that up. It was missing too many pieces - too many “in-between” species. He chalked it up to a broken archive: most of the story was lost.



Then, in 1972, scientists Stephen Jay Gould and Niles Eldredge made a bold claim. Maybe <a href="https://www.earth.com/news/octopuses-and-squids-defy-the-slow-pace-of-evolution/">species don’t evolve slowly</a> at all. Maybe they stay mostly the same for millions of years, and then - bang - something dramatic happens.



This idea, called “punctuated equilibrium,” could explain why so many transitional fossils are missing. But decades later, scientists still argue about whether it’s the rule or just a rare exception.



Now, researchers at the Institute of Evolutionary Biology (IBE) - a joint center between the <a href="https://www.csic.es/en/csic">Spanish National Research Council</a> (CSIC) and Pompeu Fabra University (UPF) - have found compelling genomic evidence that supports the “bang” theory of evolution. And the evidence comes from a very unexpected place: worms.



<h2 class="wp-block-heading" id="h-worms-and-evolution-s-missing-chapter">Worms and evolution's missing chapter</h2>



The team sequenced, for the first time, high-quality genomes of several earthworm species. They compared these to the genomes of other annelids like <a href="https://www.earth.com/news/first-proof-of-leeches-jumping-captured-on-video/">leeches</a> and bristle worms. 



The work was painstaking - done at a level of detail usually reserved for human genome studies. And it filled a major gap. Until now, scientists lacked complete genomes for many invertebrates, which made it hard to study evolution at the chromosomal level.



That changed with this study. The new genomes allowed the researchers to look back more than 200 million years.



Rosa Fernández is the lead researcher of the IBE’s Metazoa Phylogenomics and Genome Evolution Lab.



“This is an essential episode in the <a href="https://www.earth.com/news/breakthrough-discoveries-about-the-evolution-of-life-on-land/">evolution of life</a> on our planet, given that many species, such as worms and vertebrates, which had been living in the ocean, now ventured onto land for the first time,” she said. What the team found was not slow, steady change. It was upheaval.



<h2 class="wp-block-heading" id="h-worms-that-broke-all-the-rules">Worms that broke all the rules</h2>



The worm genomes didn’t just shift gradually, as traditional Neo-Darwinian models would expect. They shattered. Then they reassembled in totally new ways.



“The enormous reorganization of the genomes we observed in the worms as they moved from the ocean to land cannot be explained with the parsimonious mechanism Darwin proposed; our observations chime much more with Gould and Eldredge’s theory of <a href="https://www.earth.com/news/crocodiles-have-not-changed-much-in-200-million-years/">punctuated equilibrium</a>,” Fernández said.



In simple terms: these marine worms broke their DNA into pieces, stitched it back together in a new order, and kept going. It wasn’t just odd - it was unheard of.



Across most species, including sponges, corals, and mammals, genomic structure tends to stay surprisingly stable. This was something else entirely.



“The entire genome of the marine worms was broken down and then reorganized in a completely random way, in a very short period on the evolutionary scale,” said Fernández. “I made my team repeat the analysis again and again, because I just couldn’t believe it.”



<h2 class="wp-block-heading" id="h-surviving-dna-chaos">Surviving DNA chaos</h2>



Normally, that kind of chaos would spell extinction. But in this case, the worms didn’t just survive. They adapted. 



The research team found that annelid genomes are much more structurally flexible than those of <a href="https://www.earth.com/news/over-half-of-the-worlds-vertebrates-reside-in-the-tropics/">vertebrates</a>. That flexibility could allow genes in different parts of the genome to change positions without losing function.



The shift to land was a massive environmental change. Suddenly, these animals had to breathe air, deal with sunlight, and navigate new terrains. The genomic rewiring may have helped them adapt quickly by creating new gene combinations.



“You could think that this chaos would mean the lineage would die out, but it’s possible that some species’ evolutionary success is based on that superpower,” said Fernández.



The study suggests that some genes didn’t just move - they fused with others. These new “genetic chimeras” may have played a role in helping the worms handle life on land.



<h2 class="wp-block-heading" id="h-evolution-isn-t-orderly-for-worms">Evolution isn’t orderly for worms</h2>



This finding also raises a bigger question: is genome stability really all that important?



“It seems from this study that conserving the genomic structure at the linear level - i.e., where the genes are more or less in the same place in different species - may not be as essential as had been thought,” said Fernández. 



“In fact, stability could be the exception and not the rule in animals, which could benefit from a more fluid genome.”



That idea has serious implications. In humans, similar genomic breakdowns are seen in cancer. There’s even a term for it: chromoanagenesis. It refers to catastrophic chromosome reorganization in cancer cells. The difference? In humans, it's a disease. In these worms, it was a survival strategy.



The comparison could open up new ways to study how genomes work - and how they break.



<h2 class="wp-block-heading" id="h-dna-evidence-challenges-darwin">DNA evidence challenges Darwin</h2>



The debate between slow change and sudden leaps isn’t settled. But this study adds strong support for the idea that both models might be right, depending on the circumstances.



“Both visions, <a href="https://www.earth.com/news/charles-darwins-complete-research-library-published-for-the-first-time/">Darwin’s</a> and Gould’s, are compatible and complementary," Fernández said. "While Neo-Darwinism can explain the evolution of populations perfectly, it has not yet been able to explain some exceptional and crucial episodes in the history of life on Earth."



"Those events included such as the initial explosion of animal life in the oceans over 500 million years ago, or the transition from the sea to land 200 million years ago in the case of earthworms. This is where the punctuated equilibrium theory could offer some answers.”



And this might just be the beginning. There are thousands of invertebrate species we know almost nothing about. Their genomes may hold more surprises - and more exceptions to the rules we thought we understood.



“There is a great diversity we know nothing about, hidden in the invertebrates, and studying them could bring new discoveries about the diversity and plasticity of genomic organization, and challenge dogmas on how we think genomes are organized,” Fernández concluded.



The full study was published in the journal <a href="http://dx.doi.org/10.1038/s41559-025-02728-1">Nature Ecology &amp; Evolution</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Earthworm DNA is changing how we understand evolution, possibly proving Darwin wrong

In 1859, Darwin proposed that evolution worked slowly - even...

Bluebottles - also known as Portuguese man o’ war - are jellyfish-like marine creatures with long, stinging tentacles that often wash up on beaches. It's been widely assumed that bluebottles all belong to a single species, but a new global genetic survey has revealed otherwise.



Dr. Samuel H. Church of <a href="https://www.yale.edu/" target="_blank" rel="noreferrer noopener">Yale University</a> coordinated the genome work with Australian colleagues, including Professor Kylie Pitt from Griffith University. Their findings overturn two centuries of scientific classification.



<h2 class="wp-block-heading" id="h-four-species-of-bluebottles">Four species of bluebottles</h2>



The team sorted the <a href="https://oceanservice.noaa.gov/facts/portuguese-man-o-war.html" target="_blank" rel="noreferrer noopener">specimens</a> into Physalia physalis, P. utriculus, P. megalista, and a newly named Physalia minuta, the last discovered in waters south of New Zealand. Each species carries distinctive sail colors and float shapes - traits once dismissed as harmless variation.



Genetic markers show the four <a href="https://www.earth.com/news/world-jellyfish-day-2024-protecting-the-health-of-our-oceans/">lineages</a> do not interbreed, even when they occupy the same stretch of ocean. This pattern means evolution is at work in the open sea, not only along coastlines or around islands.



“We were shocked, because we assumed they were all the same species,” said Professor Pitt. Her remark echoes a long‑held textbook view now overturned.



Every colony is a <a href="https://twilightzone.whoi.edu/explore-the-otz/creature-features/siphonophore/" target="_blank" rel="noreferrer noopener">siphonophore</a> - a floating commune of genetically identical zooids that act as one animal. The arrangement lets a bluebottle grow long feeding tentacles while the gas‑filled float keeps the colony at the surface, a lifestyle that defines the <a href="https://theoceancleanup.com/updates/neuston-in-the-great-pacific-garbage-patch-and-the-impact-of-cleanup/" target="_blank" rel="noreferrer noopener">neuston</a> layer.



<h2 class="wp-block-heading" id="h-differences-go-beyond-appearance">Differences go beyond appearance</h2>



Raw genomes alone rarely hint at an animal’s appearance, so the researchers combed through 4,000 beach photographs. Color signatures and sail angles in the pictures matched the genetic <a href="https://www.earth.com/news/giant-phantom-jelly-discovered-exposed-ecosystem-under-antarctic-iceberg/">lineages</a> one by one.



Citizen scientists had, in effect, been taking field notes for years without knowing it. Their uploads supplied location data that helped map where each species turns up during different wind seasons. 



Machine‑learning tools flagged subtle differences, such as a deep‑purple crest on P. megalista or the small, clear float on P. minuta. Laboratory vouchers later verified those traits under a microscope.



The public photo trove also clarified left‑handed versus right‑handed sails, a feature that decides which way a bluebottle is blown. Such handedness now appears tied to species identity rather than simple developmental chance.



<h2 class="wp-block-heading" id="h-ocean-currents-separate-bluebottle-species">Ocean currents separate bluebottle species</h2>



<a href="https://www.earth.com/news/jellyfish-more-than-just-a-snack-for-predatory-fish/">Ocean</a> circulation models recreated likely drift paths from hatchling to adult, revealing corridors that keep populations apart. Prevailing winds in the Pacific sweep P. utriculus west toward Australia, while the South Equatorial Current loops P. megalista into the Atlantic.&nbsp;



The new species, P. minuta, hugs eddies of the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0924796319300259" target="_blank" rel="noreferrer noopener">Tasman Front</a>, a route that spirals larvae southward before they ever cross open ocean. Because gonads detach and sink below the surface to spawn, deep water layers also partition gene flow.



Subtle climate shifts could shuffle these corridors and mix the species in the future, but for now the lines stay crisp. That stability gives evolutionary forces room to sculpt body size, venom genes, and reproductive timing without interference. 



The finding challenges a common idea that wind‑powered drifters form one gigantic, well‑mixed population. Instead, even a creature built for travel can remain genetically provincial.



<h2 class="wp-block-heading" id="h-bluebottle-stings-vary-by-species">Bluebottle stings vary by species</h2>



<a href="https://sls.com.au/bluebottlewatch-a-new-research-project-to-develop-a-bluebottle-prediction-tool-for-our-beaches/" target="_blank" rel="noreferrer noopener">Surf Life Saving Australia</a> ranks bluebottle contact as a leading reason for first‑aid calls, spurring a research grant to build a beach sting forecast. 



Knowing which species is likely to arrive could sharpen those alerts, because tentacle length and venom chemistry differ among the four.



During the summer of 2017, more than <a href="https://www.abc.net.au/news/2017-03-01/bluebottle-stings-up-900-per-cent-in-queensland/8313970" target="_blank" rel="noreferrer noopener">38,000 people</a> were treated for bluebottle stings in Queensland alone - a spike of 900 percent over the prior season. 



<h2 class="wp-block-heading" id="h-forecasting-bluebottle-seasons">Forecasting bluebottle seasons</h2>



Public health planners can now add species identity to their toolbox instead of relying on wind direction alone.



Lighter winds often carry the smaller P. minuta onto sheltered south‑facing bays, where novice swimmers gather. 



Lifeguards armed with species‑level forecasts might adjust patrols or signage accordingly. Thermal anomalies that favor jellyfish blooms may not boost every bluebottle equally, given their genetic split.



Future sting seasons could therefore hinge on which lineage catches the breeze rather than on sheer water temperature.



<h2 class="wp-block-heading" id="h-hidden-population-structure-in-the-ocean">Hidden population structure in the ocean </h2>



The bluebottle story joins other case studies of copepods and pteropods that show hidden population structure in the high seas. 



Collectively, these results overturn the old axiom that “everything is everywhere” once an organism can drift. Marine cleanup projects often claim surface life is sparse, implying little ecological risk when skimming plastics. 



Evidence of partitioned diversity urges far more caution before nets sweep across convergence zones.



<h2 class="wp-block-heading" id="h-broader-implications-of-the-research">Broader implications of the research </h2>



Pharmaceutical scouts have isolated novel peptide toxins from P. physalis, but untapped species may hold different compounds with medical promise. A four‑species framework sets a clearer path for bioprospecting teams.&nbsp;



Climate models aiming to forecast <a href="https://www.earth.com/news/marine-robots-are-exploring-the-oceans-role-in-climate-control/">oceanic carbon</a> cycling need accurate species counts because each colony’s buoyant gas is nearly 13 percent carbon monoxide. Four distinct production rates could alter estimates of gas exchange at the air–sea interface.



Researchers who track long‑range migrants, from sea turtles to seabirds, can now refine diet studies. Predator scat may tell which bluebottle species dominates a given flyway, adding another layer to ecosystem maps.



<h2 class="wp-block-heading" id="h-toxin-genes-in-bluebottle-species">Toxin genes in bluebottle species </h2>



Work is already under way to test whether the four lineages differ in toxin genes, an angle that could explain regional differences in sting severity. 



Another puzzle lies in the handedness trait, which might be hardwired by alleles rather than molded by early winds.



Field biologists plan to tag floats with tiny temperature loggers to see how much time each species spends in sun‑baked surface water. Results should reveal whether thermal tolerance helped split the lineages in the first place.



The study is published in the journal <a href="https://www.cell.com/current-biology/abstract/S0960-9822(25)00682-7" target="_blank" rel="noreferrer noopener">Current Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Scientists were shocked to find that bluebottles are not one species

Bluebottles - also known as Portuguese man o’ war -...

Female honey bees inherit genes from their father and mother (the queen), but they don't all end up playing the same role. 



Some female bees end up becoming queens that reproduce, while others become workers that never lay eggs, and spend their lives caring for their sisters. What causes this dramatic difference?



New research points to a tug-of-war between parental genes, with mother's and father's genes pulling the developing bee larva in different directions.



<h2 class="wp-block-heading" id="h-the-role-of-parental-genes-in-a-bee-s-fate">The role of parental genes in a bee's fate</h2>



Scientists at <a href="https://www.psu.edu/" target="_blank" rel="noreferrer noopener">Penn State</a> have identified the molecular mechanism that tips the balance between <a href="https://www.earth.com/news/why-are-queen-honey-bees-failing-faster/">queen</a> and worker. The study reveals how the bee’s parents’ genes literally compete during a critical window of development.



“Imagine if your mother's genes and your father's genes were in constant disagreement about how you should develop - that is essentially what genomic imprinting is, and we see that it happens across the tree of life: from honey bees to humans,” explained Sean Bresnahan, lead author of the study.



“We found that this genetic ‘argument’ can be detected during a critical developmental window where a honey bee larva becomes either a queen or a worker.”



That window slams shut just 192 hours after the <a href="https://www.earth.com/news/world-honey-bee-day-protecting-our-vital-pollinators/">egg</a> is laid. By then, the bee's genes lock it into its destiny.



<h2 class="wp-block-heading" id="h-exploring-differences-in-bee-genes">Exploring differences in bee genes</h2>



To study the differences between the genes inherited from the mother bee (matrigenes) and those from the father bee (patrigenes), the researchers used a technique called instrumental insemination. It allowed them to control which queen mated with which drone.



The team then tracked how gene expression varied in the resulting bee larvae by analyzing RNA - the molecules that carry instructions from DNA to make proteins - and comparing gene activity based on whether it came from mother or father.



“We found patrigenes were expressed at higher levels in queen-destined larvae, and matrigenes were expressed at higher levels in worker-destined larvae,” Bresnahan said.



<h2 class="wp-block-heading" id="h-a-tug-of-war-between-bee-genes">A tug-of-war between bee genes</h2>



The team didn’t stop there. They wanted to know what these parent-specific genes were actually doing. By analyzing the cellular pathways that the genes influenced, they spotted a clear pattern.



“We saw a striking match between the expression of matrigenes and patrigenes in the same pathway,” noted Bresnahan.



“If a matrigene had increased expression then a patrigene would have decreased expression in the same pathway, or vice versa, showing that the two genes were working against each other."



"If one gene showed parent-specific expression, another gene in the same pathway showed parent-specific expression from the opposite parent.”



So it wasn’t just random. The maternal and paternal genes seemed to be locked in direct opposition, battling over the bee’s fate.



<h2 class="wp-block-heading" id="h-not-dna-methylation-this-time">Not DNA methylation this time</h2>



In many <a href="https://www.earth.com/news/where-mammals-live-depends-more-on-climate-than-human-activities/">animals</a> and plants, the mechanism that drives this kind of genetic conflict is a process called DNA methylation. It adds chemical tags to DNA that affect whether genes are turned on or off. 



But in <a href="https://www.earth.com/news/artificial-diet-offers-hope-for-saving-endangered-honey-bees/">honey bees</a>, previous research had shown that methylation doesn’t play this role. So the team looked at another possibility: histones. 



DNA isn’t just floating around loose in cells. It’s wound tightly around proteins called histones, forming a structure known as chromatin. The shape and structure of chromatin help regulate which genes are accessible and active.



Changes to histone proteins - through chemical tags placed on them - can also affect gene expression without altering the DNA itself.



<h2 class="wp-block-heading" id="h-bee-genes-are-affected-by-histones">Bee genes are affected by histones</h2>



Using a technique developed by study co-author Shaun Mahony, the researchers targeted histone-bound DNA. They isolated and analyzed the tagged histone proteins and the DNA they interacted with.



“We found that, in honey bees, parent-of-origin expression is regulated by histone modifications,” Bresnahan said.



This means chemical changes to histones - not the DNA itself - help determine which parental genes are active. And those gene activities ultimately decide if a larva will become a queen or a worker.



“What we're seeing in honey bees isn't actually that unusual when you take a step back - histone-based mechanisms for parent-of-origin effects are more widely utilized across the tree of life than DNA methylation-based systems,” explained Bresnahan.



“We see these chromatin-mediated imprinting mechanisms in flowering plants and in placental mammals as well. So, honey bees, and maybe other social insects, might be using the more ancestral toolkit for mediating these genetic conflicts,” he stated.



<h2 class="wp-block-heading" id="h-why-this-research-matters">Why this research matters</h2>



Understanding how this parental conflict works could have real-world implications. For example, it might lead to new ways to breed bees with desired traits, such as resilience or productivity.



Christina Grozinger, co-author on the study, said her lab plans to explore how these genetic dynamics affect behaviors like nursing, where some worker bees specialize in caring for young.



The project also has reach beyond insects. Bresnahan now studies how genetic conflict shapes traits in humans - especially those related to maternal-child health during pregnancy.



“The skills I developed studying parent-of-origin effects translate directly to my current studies of maternal-child health mediated through the placenta,” Bresnahan said. 



“I am particularly interested in parent-of-origin gene expression associated with placenta-mediated traits, like early-life programming of metabolic and neuropsychiatric disease risk, that could help us better understand pregnancy complications and offspring health outcomes.”



This study peels back another layer in the mystery of how similar <a href="https://www.earth.com/news/scientists-can-detect-insect-dna-in-air-samples/">DNA</a> can lead to dramatically different lives - whether in bees, humans, or plants. And it reminds us that the story of inheritance is not just about what genes we get, but also about which ones win the argument.



The full study was published in the journal <a href="https://genomebiology.biomedcentral.com/articles/10.1186/s13059-025-03628-0">Genome Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Parental genes affect whether a bee becomes a queen or a worker

Female honey bees inherit genes from their father and mother...

At first glance, sea cucumbers seem like passive creatures. They sift along the ocean floor, slow-moving and peaceful. Much like sea snails, they tend to keep to themselves. 



But unlike sea cucumbers, some species of tiny sea snails aren't so harmless. These snails aren’t just bottom-feeders - they’re parasites. And for sea cucumbers, that makes them a serious nuisance. 



In Japan, where sea cucumbers are prized as seafood, scientists have spent years cataloging the various species of parasites that live on or inside them. 



But there's been a gap in the research: one species, Holothuria leucospilota, has been tough to study. Researchers at <a href="https://www.kyoto-u.ac.jp/en">Kyoto University</a> decided it was time to change that.



<h2 class="wp-block-heading" id="h-identifying-snails-inside-a-sea-cucumber">Identifying snails inside a sea cucumber</h2>



Holothuria leucospilota defends itself by ejecting sticky threads known as Cuvierian tubules when it’s stressed. 



These threads can make dissection nearly impossible. So, to avoid triggering the defense, the team used menthol to gently anesthetize the animals before studying them.



The goal was to identify <a href="https://www.earth.com/news/sea-snails-evolved-defenses-against-invasive-predators/">snails</a> from the genus Melanella that parasitize these sea cucumbers. They did this work in Shirahama, a popular beach area in Wakayama prefecture. 



After anesthetizing the sea cucumbers, the scientists examined both the outside and the inside of the animals. They identified the snails by looking at their shell shape and analyzing their mitochondrial <a href="https://www.earth.com/news/airborne-dna-can-track-wildlife-diseases-and-even-drugs/">DNA</a>.



<h2 class="wp-block-heading" id="h-four-snails-one-sea-cucumber">Four snails, one sea cucumber</h2>



The team discovered four species of Melanella <a href="https://www.earth.com/news/marine-parasites-are-vulnerable-to-warming-oceans/">parasites</a>. Two lived on the outside of the sea cucumber, and two more were found deep inside the body cavity. 



One of the external parasites was identified as Melanella spina - the first time this species has ever been recorded in Japan. The two internal parasites couldn’t be definitively identified yet.



"Our results represent the first record of eulimids exploiting the internal habitat of H. leucospilota," said study co-author Tomoyuki Nakano. 



"To the best of our knowledge, it is also the first record of a single holothurian species, like sea cucumbers, being utilized by both external and internal Melanella parasites."



<h2 class="wp-block-heading" id="h-how-do-the-snails-get-in">How do the snails get in? </h2>



The researchers noted that these internal parasites are extremely rare - at least in Shirahama. They found two in 2022, but none in the following two years. That suggests the infection rate is low.



How these tiny snails manage to get inside the sea cucumbers is still unclear, but the team has a few leads. 



Both internal snails were found near the host’s mouth. Previous studies suggest that Melanella species often attach around this area. It's possible that the sea cucumbers accidentally ingest the snails while feeding, along with bits of sediment.



That’s one theory. Another possibility is more direct. One of the snails was found with part of its shell embedded in the sea cucumber’s body wall. That could mean it forced its way in by boring through tissue.



The invasion route is still a mystery - and that’s what the researchers want to investigate next.



<h2 class="wp-block-heading" id="h-parasitism-across-the-animal-kingdom">Parasitism across the animal kingdom </h2>



What the researchers observed in sea cucumbers isn’t unique. Nature is full of strange and sometimes unsettling examples of animals parasitizing others - both in the ocean and on land.



One well-known ocean example is the tongue-eating louse (Cymothoa exigua), a parasite that enters a fish’s mouth, attaches to its tongue, and eventually replaces it. The fish continues to live and eat, even as the louse occupies a central role in its body.



On land, <a href="https://www.earth.com/news/parasitic-wasp-had-a-flytrap-for-snatching-its-victims/">parasitic wasps</a> are notorious for their ruthless tactics. Some species lay their eggs inside caterpillars, and when the larvae hatch, they feed on the host from the inside out. In many cases, the host stays alive until the wasps are fully developed and ready to emerge.



Even in mammals, parasites play a role. Botflies, for instance, lay their eggs on animals like rodents or livestock, and the larvae burrow into the skin to grow.



These examples show that <a href="https://www.earth.com/news/extreme-parasitism-balanophora-convinces-a-host-to-grow-into-its-tissue/">parasitism</a> is a successful - if grisly - survival strategy across the animal kingdom. What makes the Melanella-sea cucumber relationship fascinating is how subtle and understudied it remains. 



Scientists are only just beginning to understand how complex these interactions can be, especially when the host makes access so difficult.



The full study was published in the journal <a href="https://bioone.org/journals/zoological-science/volume-42/issue-4/zs250003/Co-Occurrence-of-Gastropods-of-the-Genus-Melanella-Mollusca/10.2108/zs250003.short">ZOOLOGICAL SCIENCE</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Parasitic snails are sneaking inside sea cucumbers

At first glance, sea cucumbers seem like passive creatures. They...

Dogs did not dash into South America with the first humans. Instead, they arrived slowly, traveling with early farmers. A new study uncovers this deliberate journey and connects it to the spread of agriculture and maize cultivation. 



A research team led by Dr. Aurélie Manin analyzed 70 mitochondrial genomes from ancient and modern dogs found between Mexico and Argentina.



The analysis revealed that dogs followed a slow southward path, not with hunter-gatherers, but with farming societies that were transforming the land around 7,000 to 5,000 years ago.



<h2 class="wp-block-heading" id="h-all-ancient-dogs-came-from-one-lineage">All ancient dogs came from one lineage</h2>



The study also revealed a single maternal lineage, the A2b1 haplogroup, as the root of all pre-contact dogs in Central and South America. This lineage emerged after dogs entered North America and gradually split as they moved southward. 



<a href="https://www.earth.com/news/famous-ice-age-puppies-are-not-actually-dogs-according-to-new-study/">Dogs</a> likely crossed cultural and ecological boundaries slowly, adapting as they traveled alongside human groups.



The researchers found no signs of other A2b subgroups in South America. Thirty-six archaeological dogs fell into A2b1, forming a tightly clustered clade, with no early presence in the Amazon Basin. 



Genetic data shows that dogs in North, Central, and South America stayed regionally distinct, indicating minimal female-dog movement between areas.



<h2 class="wp-block-heading" id="h-dogs-spread-with-ancient-maize-farmers">Dogs spread with ancient maize farmers</h2>



The arrival of <a href="https://www.earth.com/news/humans-and-dogs-were-bonding-much-earlier-than-we-thought/">dogs</a> in South America matches the introduction of maize agriculture. According to the study, maternal lineages of northern and southern dogs split around 7,000 years ago - around the same time maize began its journey south.



The results suggest that dogs spread with farmers rather than earlier foraging groups.



“We show that their spread was slow enough to allow the dogs to structure genetically between north, central and south America,” said Dr Manin. “It opens new research avenues on the relationship that existed between dogs and these early agrarian societies.”



The researchers tested this with molecular clocks and population models. Their data showed a north to south diversification pattern in ancient dogs. 



The timing aligns with archaeological remains of ancient dogs found in Mexico, Peru, and Argentina - all appearing after the earliest human settlements.



<h2 class="wp-block-heading" id="h-why-the-delay-in-arrival">Why the delay in arrival?</h2>



The study offers possible reasons for the delay in the arrival of dogs. Early foragers may not have needed dogs, or the tropical corridor posed too many risks such as disease, predators, or lack of food. 



European colonial records confirm that dogs remained vulnerable to these threats even in the 1700s.



This delay mirrors what happened in Europe, where Neolithic farmers replaced earlier <a href="https://www.earth.com/news/from-wolves-to-dogs-did-domestication-begin-without-human-help/">dog</a> lineages with ones from the Levant. The Americas may have seen a similar turnover during the farming transition.



<h2 class="wp-block-heading" id="h-some-dogs-still-carry-ancient-dna">Some dogs still carry ancient DNA </h2>



Colonial contact brought European dog lineages, which quickly replaced most indigenous dogs. Yet, not everything was lost. 



Some modern Chihuahuas still carry mitochondrial DNA from the ancient A2b1 clade. One Chihuahua's maternal line traces back over 1,500 years to pre-contact Mesoamerican dogs.



The researchers also found dogs in modern Peru with mitochondrial DNA belonging to European lineages. These lineages first appeared in Europe over 14,000 years ago and now dominate the Americas.



Still, ancient bonds with dogs left deeper marks. In some regions, archaeological burials show how ancient dogs were cared for and mourned. 



Early farmers may have used ancient dogs for protection, meat, or companionship. Farming surpluses could have supported feral ancient dogs or drawn scavengers.



<h2 class="wp-block-heading" id="h-the-journey-of-dogs-and-farming">The journey of dogs and farming</h2>



This study reshapes our view of dog-human history in the Americas. It places agrarian societies, not foragers, at the center of dog expansion. This pattern aligns with other regions like East Asia, where dog dispersal followed farming and surplus food.



The research also shows the fragility of early genetic lineages. Most pre-contact dog DNA is now gone, erased by colonial waves. But rare survivors, like the Chihuahua, still carry whispers of the past.



The study encourages further research using nuclear DNA analysis and isotopic methods. These advanced tools can reveal more than just the origins of ancient dogs. 



The tools can help scientists understand how ancient dogs lived, how they moved across regions, and how they interacted with early American communities.



This deeper knowledge could uncover the everyday roles ancient dogs played in human societies and how those relationships evolved over time.



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2024.2443" target="_blank" rel="noreferrer noopener">Proceedings of the Royal Society B Biological Sciences</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Scientists discover how dogs spread across the Americas

Dogs did not dash into South America with the first...

The skies were empty for most of Earth’s history, but then light‑boned reptiles mastered powered flight roughly 220 million years ago. 



A new analysis of fossil maps and computer climate models shows that warm, damp air, not desert heat, gave those first <a href="https://www.earth.com/news/new-fossil-fills-crucial-gap-in-pterosaur-evolution/">pterosaurs</a> the environmental boost they needed.



Davide Foffa of the <a href="https://www.birmingham.ac.uk/">University of Birmingham</a> led the work with Emma Dunne at Friedrich‑Alexander‑Universität Erlangen‑Nürnberg and Alessandro Chiarenza at University College London.



<h2 class="wp-block-heading" id="h-pterosaurs-lived-in-humid-regions">Pterosaurs lived in humid regions </h2>



Foffa’s team plotted every Triassic pterosaur and <a href="https://www.sciencedirect.com/science/article/abs/pii/S0895981124001196" target="_blank" rel="noreferrer noopener">lagerpetid</a> fossil they could verify, covering what was then the single supercontinent <a href="https://www.usgs.gov/faqs/what-was-pangea" target="_blank" rel="noreferrer noopener">Pangea</a>. 



The map revealed a pattern: early flyers cluster in low‑latitude sites that ancient climate simulations mark as humid, while their land‑bound cousins spread across drier belts.



Lagerpetids, rat‑ to dog‑sized sprinters, never left the ground yet roamed from today’s Brazil to the American Southwest. Ezcurra and colleagues confirmed in <a href="https://www.nature.com/articles/s41586-020-3011-4" target="_blank" rel="noreferrer noopener">2020</a> that these agile reptiles form the sister branch to <a href="https://www.earth.com/news/pterosaur-bones-biomimicry-could-inspire-better-aircraft-technology/">pterosaurs</a>.



<h2 class="wp-block-heading" id="h-pterosaur-flight-needed-humid-forests">Pterosaur flight needed humid forests</h2>



The question of why pterosaurs took flight when they did has puzzled researchers for decades. Their closest relatives, lagerpetids, had the anatomical tools for agility and climbing, but lacked the skeletal adaptations needed for powered flight.



Foffa’s team suggests it wasn’t just biology holding them back - it was the environment. Without expansive forest canopies and consistently humid ecosystems, early pterosaur <a href="https://www.earth.com/news/pterosaurs-took-flight-millions-of-years-before-birds/">ancestors</a> may have lacked both the resources and the ecological pressure to evolve wings sooner.



<h2 class="wp-block-heading" id="h-rainfall-surge-led-to-pterosaur-flight">Rainfall surge led to pterosaur flight</h2>



As carbon‑rich volcanism drove the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7494334/" target="_blank" rel="noreferrer noopener">Carnian Pluvial Episode</a> about 234 million years ago, average rainfall spiked for roughly two million years. Forests thickened, insect populations jumped, and treetop launchpads multiplied exactly when the first pterosaur bones appear.



To test cause and effect, the authors fed Triassic geography into the <a href="https://www.metoffice.gov.uk/research/approach/modelling-systems/unified-model/climate-models/hadcm3" target="_blank" rel="noreferrer noopener">HadCM3L general circulation model</a>, a tool normally used for <a href="https://www.nhm.ac.uk/discover/the-cretaceous-period.html" target="_blank" rel="noreferrer noopener">Cretaceous</a> and future‑climate work. 



The simulation reproduced humid bands along the equator that matched every known <a href="https://www.sciencedirect.com/science/article/abs/pii/S0012825221002786" target="_blank" rel="noreferrer noopener">Norian pterosaur</a> site within a margin of about 60 miles.



<h2 class="wp-block-heading" id="h-fossils-and-climate-maps-tell-the-story">Fossils and climate maps tell the story</h2>



To connect ancient reptile evolution with <a href="https://www.earth.com/news/cracking-the-code-of-pterosaur-flight-soaring-vs-flapping/">prehistoric</a> climate, the researchers needed more than just bones. They used global climate models that simulate temperature, precipitation, and seasonal variation from over 200 million years ago, then overlaid fossil data on those maps.



This approach revealed strong patterns. Pterosaur fossils linked to flight consistently appeared in regions the model predicted to be wet and forested.



On the other hand, lagerpetids showed up in a broader range of habitats, including dry, seasonal areas. These overlapping maps helped confirm the environmental preferences of each group.



<h2 class="wp-block-heading" id="h-humid-air-and-the-rise-of-flying-reptiles">Humid air and the rise of flying reptiles</h2>



“Their wings catapulted them into every corner of the planet,” noted Chiarenza. Later Triassic decades saw wetter air creep poleward, and the fossil record follows: specimens pop up in what is now Greenland and Argentina, hundreds of miles from the original belt.



Marine <a href="https://www.nature.com/articles/s41467-018-03996-1" target="_blank" rel="noreferrer noopener">records</a> show that the same wet pulse coincided with a 33 percent loss of ocean genera and rapid dinosaur diversification, hinting at a broader reshuffling. 



Dunne noted that climate change is a leading cause of biodiversity change, both in the present day and the geological past - a reminder that weather can redraw evolutionary maps.



<h2 class="wp-block-heading" id="h-pterosaur-flight-aided-survival-for-some">Pterosaur flight aided survival for some</h2>



Lagerpetids tolerated scorchingly dry interiors yet vanished at the <a href="https://samnoblemuseum.ou.edu/understanding-extinction/mass-extinctions/end-triassic-extinction/" target="_blank" rel="noreferrer noopener">end‑Triassic extinction</a>, while their winged relatives sailed through the crisis. Flight likely offered escape from predators and fire, plus access to scattered resources after forests burned.



The disappearance of lagerpetids at the end of the Triassic remains a mystery, especially since they had a broader climate tolerance and geographic range than early pterosaurs. 



Some scientists suggest they may have lacked the specialized adaptations - like flight - that helped other groups escape or adapt to rapid ecosystem changes.



Others think competition may have played a role. As pterosaurs and early dinosaurs spread into new environments, they may have outcompeted lagerpetids for food or territory, leaving the once-thriving reptiles with fewer niches to occupy.



<h2 class="wp-block-heading" id="h-clues-for-future-fossil-hunts">Clues for future fossil hunts</h2>



“Model outputs flag humid Triassic pockets in Morocco, India, and the American Midwest where no pterosaur bones have been logged. Field crews may strike pay dirt there, especially in fine‑grained lake shales that entomb fragile skeletons whole,” explained Foffa.



The research links a short‑lived climate swing to a permanent ecological shake‑up in which pterosaur flight emerged, demonstrating how quickly new winners appear when habitats shift.



With modern CO₂ levels rising on a similar scale, today’s ecosystems could see equally swift turnovers, though not necessarily as majestic as a <a href="https://www.sciencedirect.com/science/article/abs/pii/S0895981124001196" target="_blank" rel="noreferrer noopener">Pterosauromorpha</a> liftoff.



The study is published in the journal <a href="https://www.nature.com/articles/s41559-025-02767-8" target="_blank" rel="noreferrer noopener">Nature Ecology &amp; Evolution</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Humid air gave pterosaurs the boost they needed to take flight

The skies were empty for most of Earth’s history, but...

Dolphins, like other toothed whales, live in a world of darkness where light fades fast. They stay oriented by sending out quick clicks and reading the echoes, a process known as echolocation. 



Each click acts like a tap on the water, letting their brains “feel” distant objects and fish through sound alone.



In a new study, a team of scientists led by the Woods Hole Oceanographic Institution (<a href="https://www.whoi.edu/" target="_blank" rel="noreferrer noopener">WHOI</a>) traced how this talent shows up inside the brain.



The study compares the neural wiring of echolocating dolphins to that of a species of non-echolocating baleen whale called a sei whale.



<h2 class="wp-block-heading" id="h-understanding-echolocation-the-basics">Understanding echolocation - the basics</h2>



Echolocation in marine mammals is a sophisticated biological sonar system that allows animals like dolphins, whales, and porpoises to navigate, hunt, and <a href="https://www.earth.com/news/dolphins-must-shout-over-underwater-noise-to-communicate/">communicate</a> in dark or murky underwater environments. 



These mammals emit a series of high-frequency clicks that travel through the water and bounce off objects. By listening to the returning echoes, they can determine the size, shape, distance, speed, and even internal structure of their targets. 



This process gives them an incredibly detailed picture of their surroundings, often surpassing what sight alone could provide in deep or cloudy waters.



This adaptation is especially critical for species that live in environments where visibility is limited. For example, <a href="https://www.earth.com/news/bowhead-whales-dive-in-synchrony-even-when-out-of-acoustic-range/">deep-diving whales</a> rely on echolocation to locate prey thousands of feet below the surface, where light cannot penetrate. 



Echolocation also plays a key role in social behavior, helping individuals coordinate movements or avoid collisions while swimming in pods. 



Remarkably, some species can even adjust the frequency and intensity of their clicks to focus on specific tasks, much like humans adjusting the lens on a camera.



<h2 class="wp-block-heading" id="h-studying-echolocation-in-dolphins">Studying echolocation in dolphins</h2>



Brain tissue from deceased, stranded animals is hard to obtain and even harder to scan. By partnering with the International Fund for Animal Welfare (<a href="https://www.ifaw.org/" target="_blank" rel="noreferrer noopener">IFAW</a>), the team secured enough samples to begin charting auditory circuits in detail.



“Our research sought to understand how the pathways for auditory information differed between echolocating and non-echolocating whales," said lead author Sophie Flem. 



"In humans, primates, rodents, and dogs, we have well-established maps of what parts of the brain contribute to what kind of processing. We don't yet have those in dolphin brains, which are strikingly <a href="https://www.earth.com/earthpedia-articles/are-dolphins-smart-how-are-dolphins-intelligent/">unusual</a> compared to terrestrial animal brains," she added.



Researchers traced signals leaving the inferior colliculus, a mid-brain hub that all <a href="https://www.earth.com/earthpedia-articles/are-dolphins-sharks-and-whales-mammals/" target="_blank" rel="noreferrer noopener">mammals</a> share. 



In dolphins, this region is oversized, making it an ideal place to follow sound information as it travels into the cortex.



The team found more cortical targets in dolphins than in the sei whale, yet the strength of those links was similar. 



<h2 class="wp-block-heading" id="h-cerebellum-s-role-in-dolphin-echolocation">Cerebellum's role in dolphin echolocation</h2>



The biggest surprise lay in the pathways heading the other way - down toward the cerebellum.



“While neuroscientists used to think of the cerebellum largely as a center for balance and motor (muscle/movement) control, newer evidence strongly suggests that it serves as an integration center for sensory and motor information and, importantly, a rapid prediction center," explained co-author Peter Tyack, emeritus research scholar in biology at WHOI.



“Dolphins use echolocation to <a href="https://www.earth.com/news/listening-to-amazon-river-dolphins-can-help-us-save-them/">interact with their world</a> and, unlike hearing and vision, they must produce the energy that then returns to their sensory receptors - echolocation is part hearing and part vocalization," explained Tyack.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/06/echolocation_dolphins_cerebellar-lobules_graphic_credit-PLOSOne_1m.jpg"><img src="https://www.earth.com/wp-content/uploads/2025/06/echolocation_dolphins_cerebellar-lobules_graphic_credit-PLOSOne_1s.webp" alt="Color-coded diagram displaying cerebellar lobules targeted in the left, right, or bilateral cerebella in odontocete and mysticete specimens. Credit: PLOS One" class="wp-image-1974812"/></a><figcaption class="wp-element-caption">Color-coded diagram displaying cerebellar lobules targeted in the left, right, or bilateral cerebella in odontocete and mysticete specimens. Click image to enlarge. Credit: PLOS One</figcaption></figure>



He likened the process to a person using a hand to produce the touch sense feedback that lets him or her find the light switch. 



In a similar manner, dolphins move around their echolocation beam to get the feedback they need to function in a dark, underwater environment.



<h2 class="wp-block-heading" id="h-imaging-brains-the-size-of-suitcases">Imaging brains the size of suitcases</h2>



Scanning a sei whale brain - nearly three times heavier than a human brain - posed technical challenges.



Oxford’s Karla Miller developed high-signal diffusion sequences, while UC Berkeley’s Ben Inglis optimized collection protocols. 



The result is some of the clearest diffusion imagery ever captured from large <a href="https://www.earth.com/news/marine-mammals-in-the-us-are-highly-vulnerable-to-climate-change/" target="_blank" rel="noreferrer noopener">marine mammal</a> brains.



"Comparative neurobiologists have longed to examine the patterns of connections within dolphin and whale brains for years, believing that the unique evolutionary history of these species will provide new insights into how brains evolve," said senior author Peter Cook of <a href="https://www.ncf.edu/" target="_blank" rel="noreferrer noopener">New College of Florida</a>.



The technology is now available to begin tackling these mysterious nervous systems and finding out how they work. 



<h2 class="wp-block-heading" id="h-mapping-dolphin-echolocation-regions">Mapping dolphin echolocation regions</h2>



Cook and colleagues already have more baleen and toothed whale brains queued for study. 



"It's believed that neural control of vocal output has totally shifted in dolphins as they evolved their unique nasal vocal apparatus. We can now map out vocal control in dolphins and how it differs from baleen whales," remarked Cook.



Both groups of animals have the rare ability to learn new vocal behavior, and dolphin <a href="https://www.earth.com/news/dolphins-smile-at-each-other-when-they-are-feeling-playful/" target="_blank" rel="noreferrer noopener">vocal systems</a> are some of the strangest in the animal kingdom. 



"Now that we can opportunistically and ethically look inside these animals' brains, they're just getting started teaching us," Cook concluded.



The team hopes that future maps of vocal pathways will reveal how sound production and perception blend together in one of nature’s most sophisticated sonar systems.



The full study was published in the journal <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0323617" target="_blank" rel="noreferrer noopener">PLOS One</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.



-----

Scientists learn how dolphin brains evolved to 'see' underwater by using sound

Dolphins, like other toothed whales, live in a world of...

Anyone who has watched a cat sleep knows they do so with remarkable consistency. From curled tails to neatly tucked paws, their resting positions often seem almost ritual-like. But new research suggests the sleeping positions of cats are not just habits.



A global research team has found that most <a href="https://www.earth.com/news/cats-can-tell-people-apart-by-sniffing-them/">cats</a> prefer to sleep on their left side. By analyzing 408 YouTube videos, the researchers confirmed a significant bias toward this sleeping position. 



About 65% of the cats were seen resting with their left shoulder down, while only 35% chose the right side. "Sleeping on the left side can therefore be a survival strategy,” noted the researchers.



<h2 class="wp-block-heading" id="h-cats-sleep-left-to-react-faster">Cats sleep left to react faster</h2>



When a cat sleeps on its left, it wakes up using its left visual field. This field is processed in the brain’s right hemisphere, which handles spatial awareness, fear response, and fast movement coordination. 



“Asymmetries in behavior can have advantages because both hemispheres of the brain specialize in different tasks,” explained study co-author Onur Güntürkün.



Left-side sleeping allows cats to respond faster to threats from below or from the left. This sleep posture aligns with <a href="https://www.earth.com/news/international-lynx-day-2025-protecting-the-silent-hunters/">cats</a>’ tendency to rest in high places. 



Elevated locations limit predator access and provide better visibility. Combined with leftward sleeping, this may give cats a stronger edge when suddenly waking.



<h2 class="wp-block-heading" id="h-a-strong-left-side-bias">A strong left-side bias</h2>



The team examined only clear, unaltered videos showing single <a href="https://www.earth.com/news/how-and-why-do-cats-purr-scientists-finally-found-the-answers-genetic-dna/">cats</a> lying fully visible on one side for at least 10 seconds. Videos that were mirrored, low-resolution, or cropped were excluded. 



The results were statistically significant (χ² = 37.7, df = 1, p &lt; 0.001), showing a clear left-side preference.



This bias may not be random. It fits well with patterns seen in many species, where the right brain hemisphere plays a major role in detecting danger. 



Animals generally react faster to threats coming from their left side, suggesting an adaptive benefit to this positioning.



<h2 class="wp-block-heading" id="h-the-right-brain-helps-detect-danger">The right brain helps detect danger</h2>



“By specializing on one limb or one side of its sensory system, the contralateral hemisphere goes through life-long cycles of motor and perceptual learning,” wrote the study authors.



This helps speed up brain processing, cut down reaction times, and enhance accuracy. Sleeping with the left shoulder down lets the brain’s stronger threat-response side engage instantly when the cat awakens.



The right amygdala, which helps process fear, is more active in the right side of the brain. Since the right side also handles things like noticing space and spotting danger, this supports the idea that sleeping on one side may be linked to fear.



<h2 class="wp-block-heading" id="h-other-causes-for-cat-sleep-bias">Other causes for cat sleep bias</h2>



Could other factors influence sleep position? Maybe, but they are unlikely to change the overall pattern. For instance, pregnant cows lie on their left with moderate frequency. However, pregnancy rates alone cannot explain the strong leftward bias in this cat sample.



Another possible explanation is “pawedness,” preference for using one paw over the other. Around 78% of cats show some degree of paw preference. But left- and right-pawed cats occur in equal numbers. So paw dominance does not match the 65% left-sleeping pattern seen here.



Still, researchers caution that more studies are needed. The team had no access to sex or pregnancy data for the cats in the videos. But the strong population-level trend remains clear.



<h2 class="wp-block-heading" id="h-cats-sleep-habits-reveal-brain-evolution">Cats sleep habits reveal brain evolution</h2>



This finding adds to the growing evidence that cats, like many <a href="https://www.earth.com/news/cats-have-become-one-of-the-worlds-most-invasive-predators/">animals</a>, use subtle behavioral traits to stay safe. It also supports broader patterns of brain lateralization seen across mammals and birds.



The researchers believe these insights can help researchers understand how such asymmetries emerge. 



“Although this finding is subject to debate, it could provide an excellent opportunity to study the emergence of asymmetries at the population level,” they wrote.



For pet owners and scientists alike, this sleepy behavior may offer surprising clues about how brains and bodies work together to enhance survival and adaptation.



The study was led by researchers from the&nbsp;<a href="https://www.uniba.it/" target="_blank" rel="noreferrer noopener">University of Bari Aldo Moro</a>,&nbsp;<a href="http://www.ruhr-uni-bochum.de/en" target="_blank" rel="noreferrer noopener">Ruhr University Bochum</a>,&nbsp;<a href="https://www.medicalschool-hamburg.de/" target="_blank" rel="noreferrer noopener">Medical School Hamburg</a>, and other international partners.



The study is published in the journal <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(25)00507-X" target="_blank" rel="noreferrer noopener">Current Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Cats clearly prefer sleeping on their left side, here's why

Anyone who has watched a cat sleep knows they do...

For over a century, scientists have debated how mammals shifted from sprawling like reptiles to walking upright. This transition marked one of the most significant events in vertebrate evolution. It shaped how mammals, from bats to humans, move through their world.



While earlier views suggested a simple step-by-step progression, new research suggests a very different path. 



A study led by Dr. Robert Brocklehurst of the <a href="https://www.reading.ac.uk" target="_blank" rel="noreferrer noopener">University of Reading</a> shows that upright posture evolved through a complex branching <a href="https://www.earth.com/news/pet-dogs-severely-harm-wildlife-even-when-leashed/">process</a>.



<h2 class="wp-block-heading" id="h-evolution-of-upright-posture-in-mammals">Evolution of upright posture in mammals </h2>



“The evolution of mammals has previously been characterized as a series of steps from sprawling, to semi-sprawling, to upright,” said Dr. Brocklehurst. “However, what we discovered was a more nonlinear evolutionary progression throughout mammalian <a href="https://www.earth.com/news/dog-nose-shapes-could-help-explain-human-birth-defects/">history</a>.”



The researchers analyzed over 200 species of tetrapods. They compared humerus bones across fossilized synapsids and modern animals like salamanders, reptiles, monotremes, and upright mammals. 



The team examined traits such as bone length, torsion, bending strength, and muscle leverage.



Rather than showing a clear ladder of progress, the data revealed bursts of change. Different mammalian ancestors experimented with varying forelimb functions. These experiments shaped the eventual rise of upright walking.



<h2 class="wp-block-heading" id="h-mapping-the-mechanics-of-movement">Mapping the mechanics of movement</h2>



The researchers used a computational model to connect bone shape with function and posture. They created adaptive landscapes that linked bone mechanics to different walking <a href="https://www.earth.com/news/dogs-can-recognize-familiar-human-voices-even-in-recordings/">styles</a> - sprawled or upright.



“By correlating bone shape and limb biomechanics with posture, we could test how well the fossil bones were optimized for specific functional tasks, like upright walking versus sprawled walking,” said Dr. Brocklehurst.



“We expected to see a neat progression - from sprawling pelycosaurs to a bit more upright therapsids, then cynodonts, then fully upright mammals. Instead, we found bursts of innovation.”



The team discovered that while early synapsids did have sprawling limbs, they didn’t function like modern reptiles. 



“They’re not just copies of reptiles, but distinctive animals in their own right that are a little different from anything that’s alive today," said said Dr. Kenneth Angielczyk of the University of Chicago.



<h2 class="wp-block-heading" id="h-mammals-tried-many-movement-styles">Mammals tried many movement styles</h2>



This research challenges the idea of direct, staged transitions. Instead of rigid postural categories, the ancestors of <a href="https://www.earth.com/news/why-do-cats-outlive-dogs-clues-found-in-their-genes/">mammals</a> explored many forms of limb use.



“Previous hypotheses posit the synapsid ‘sprawling-parasagittal’ transition as a series of discrete postural shifts; our study supports the view of synapsid evolution as a series of successive radiations, with major clades exhibiting considerable functional (and postural) variation,” the researchers wrote.



“While the ancestors of mammals did generally get more upright as time went on, there was a lot of variation in each major group of mammalian ancestors.”



Professor Stephanie Pierce of <a href="https://www.harvard.edu" target="_blank" rel="noreferrer noopener">Harvard University</a> noted that the path to upright posture wasn’t a straight line. "The ancestors of mammals weren’t steps on a ladder with modern mammals at the top."



<h2 class="wp-block-heading" id="h-muscles-behind-mammalian-motion">Muscles behind mammalian motion</h2>



The upright posture of modern mammals required deep musculoskeletal changes. This included shifts in bone shape and how muscles interacted with the skeleton. 



The study showed that parasagittal posture - the fully upright limb arrangement - appeared relatively late in mammal history.



“Our work challenges the idea that posture changed gradually and early on,” said Professor Pierce. “Instead, it shows that upright posture and locomotion were a late evolutionary innovation, not an early defining trait of the mammalian lineage.”



“Understanding how mammals came to walk upright isn’t just about bones. It’s about uncovering the dynamic history of life on Earth," said Dr. Brocklehurst.



The researchers acknowledge some limitations in their study. These include uncertainties in evolutionary timelines and divergence dates. However, the large dataset and mechanical modeling provide a strong framework for future research.



<h2 class="wp-block-heading" id="h-tracing-upright-posture-in-mammals">Tracing upright posture in mammals</h2>



To compare hundreds of bones from vastly different animals, the team had to innovate. Traditional shape analysis tools failed. So, they retooled an R software package into a “slice-based” landmarking system.



This approach allowed for precise measurement of traits even across species separated by millions of years. Former undergraduate Magdalen Mercado helped assemble the dataset, contributing to the massive scope of the project.



Professor Pierce reflected on the legacy of Harvard researchers who tackled similar questions decades ago. “Now, with new tools and data, we can revisit those ideas and see the story more clearly.”



“This delayed acquisition [of upright posture] ultimately laid the foundation for the extraordinary ecological success of mammals,” said Pierce.



<h2 class="wp-block-heading" id="h-new-chapter-in-mammalian-evolution">New chapter in mammalian evolution</h2>



This study is the first of its kind to use large-scale biomechanics to trace mammalian posture. It reveals that upright walking didn’t come early, but evolved after numerous experiments in movement.



As the team continues modeling limb function in fossil species, they aim to unlock more details about how ancient creatures lived and moved.



“The origin of upright mammalian posture is a key part of their evolutionary story,” said Dr. Brocklehurst. 



“People have been working on this problem for over 100 years. We knew we needed to see as many fossils as possible, and really get to grips with bone function and mechanics, not just shape.”



With this broader view, scientists now see evolution not as a tidy path, but as a dynamic landscape full of surprises.



The study is published in the journal <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003188" target="_blank" rel="noreferrer noopener">PLOS Biology</a>.



-----



Like what you read? <a href="https://www.earth.com/subscribe/">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.&nbsp;



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/">Eric Ralls</a> and Earth.com.



-----

Mammals tried different ways to move before walking upright

For over a century, scientists have debated how mammals shifted...

species in Dipodidae

News coming your way