var icx_publication_id = 14770; 
var icx_content_id = 2575210;

What is Cadmium?

Tiny bits of plastic no wider than a human hair have turned up in some unexpected places, including the human bloodstream. 



Now, data presented at the European Society of Human Reproduction and Embryology meeting shows that these <a href="https://www.earth.com/news/microplastics-spread-deep-into-the-ocean-far-below-the-surface/">fragments</a> have breached the fluids that surround eggs and travel with sperm.



The research team led by Dr. Emilio Gómez‑Sánchez of Next Fertility Murcia in Spain scanned <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/follicular-fluid" target="_blank" rel="noreferrer noopener">follicular fluid</a> from 29 women and seminal fluid from 22 men.



The experts found microplastics in 69 percent of the women and 55 percent of the men they studied. According to Dr. Gómez‑Sánchez, the team was surprised to find that the particles were so widespread.



<h2 class="wp-block-heading" id="h-plastics-in-human-reproductive-fluids">Plastics in human reproductive fluids</h2>



The study detected polymers such as <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/polytetrafluoroethylene" target="_blank" rel="noreferrer noopener">polytetrafluoroethylene</a> and <a href="https://adrecoplastics.co.uk/polypropylene-uses/" target="_blank" rel="noreferrer noopener">polypropylene</a>, materials better known for slick frying pans and food packaging. Seeing them next to human eggs turns a theoretical hazard into a measurable one.



Back in 2021, Italian obstetricians spotted twelve plastic fragments in every placenta they examined, confirming that particles smaller than five millimeters can cross the <a href="https://pubmed.ncbi.nlm.nih.gov/33395930/" target="_blank" rel="noreferrer noopener">maternal‑fetal boundary</a>.



Similarly sized particles have been uncovered deep in <a href="https://pubmed.ncbi.nlm.nih.gov/35364151/" target="_blank" rel="noreferrer noopener">lung tissue</a> removed during surgery, proving that inhalation is a realistic delivery route for <a href="https://www.earth.com/news/simple-way-to-remove-microplastics-from-tap-water-home-faucet/">plastic</a> dust.



Researchers in the Netherlands have even measured plastic mass circulating in human blood samples, an <a href="https://pubmed.ncbi.nlm.nih.gov/35367073/" target="_blank" rel="noreferrer noopener">observation</a> that explains how fragments migrate to distant tissues.



<h2 class="wp-block-heading" id="h-how-plastics-enter-the-human-body">How plastics enter the human body</h2>



Most people take in <a href="https://www.earth.com/news/microplastics-in-human-brains-may-affect-mental-health/">plastic</a> flecks by eating, drinking, or breathing, because everyday products shed invisible dust whenever they are heated, abraded, or exposed to sunlight. 



Once swallowed or inhaled, particles small enough can slip through the gut wall or the thin air‑blood membrane in the lungs.



Animal studies suggest that fragments under one micrometer can enter cells directly, whereas larger shards get trapped in tissue and spark local irritation. Either way, they bypass the body’s usual waste filters.



Laboratory work on mice shows that digestive uptake rises when <a href="https://www.earth.com/news/airborne-microplastics-where-they-come-from-and-where-they-go/">microplastics</a> hitchhike on fats, a detail that matters for fertility research because reproductive hormones ride on similar lipid highways. 



The overlap raises worry that plastics may act as endocrine mimics or carriers for other chemicals.



Dr. Gómez‑Sánchez’s team avoided laboratory contamination by collecting every human sample in glass vials and verifying the absence of background plastic. This means the polymers they found were genuine residents, not stray lab dust.



<h2 class="wp-block-heading" id="h-plastic-harms-fertility">Plastic harms fertility</h2>



Mice exposed to polystyrene fragments shed sperm with damaged DNA and sluggish movement, effects traced to <a href="https://pubmed.ncbi.nlm.nih.gov/31896473/" target="_blank" rel="noreferrer noopener">oxidative stress</a> that overwhelms antioxidant defenses.



Separate <a href="https://pubmed.ncbi.nlm.nih.gov/36948006/" target="_blank" rel="noreferrer noopener">work</a> on rodent Leydig cells shows shriveled mitochondria after nanoplastic exposure, which throttles testosterone production and shrinks litter sizes.



Reviews published in 2024 concluded that microplastics can disrupt the <a href="https://pubmed.ncbi.nlm.nih.gov/38750730/" target="_blank" rel="noreferrer noopener">hypothalamic‑pituitary‑gonadal axis</a>, leading to hormonal imbalances and faulty egg maturation.



Because human oocytes develop over months, chronic exposure could matter more than a short spike. That makes the repeated detection of PTFE in both eggs and sperm especially noteworthy.



<h2 class="wp-block-heading" id="h-plastic-levels-in-eggs-and-sperm">Plastic levels in eggs and sperm</h2>



In the current data set, PTFE appeared in 31 percent of sampled egg fluid and 41 percent of semen. PP ranked second among women and <a href="https://www.chemicalsafetyfacts.org/chemicals/polystyrene/" target="_blank" rel="noreferrer noopener">polystyrene</a> second among men, with <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/polyethylene-terephthalate" target="_blank" rel="noreferrer noopener">polyethylene terephthalate</a> also present but in smaller numbers.



Annual plastic output has climbed from under two million tons in 1950 to about 460 million in 2019, a 230‑fold jump documented by the <a href="https://pubmed.ncbi.nlm.nih.gov/36969097/" target="_blank" rel="noreferrer noopener">Minderoo‑Monaco Commission on Plastics and Human Health</a>.



Each uptick in production increases litter, weathering, and fragment release, tightening the feedback loop between plastics and people. Reproductive cells, delicate by design, stand on the front line.



Gómez‑Sánchez reported that most reproductive samples contained only one or two plastic particles, amounts considered low compared with overall debris in the fluids. Yet fertility specialists note that even trace metals can derail embryo development, so particle counts alone may not predict risk.



<h2 class="wp-block-heading" id="h-human-fertility-research-must-include-plastics">Human fertility research must include plastics</h2>



“They should be considered an additional argument in favor of avoiding the generalized use of plastics in our daily lives,” said Professor Carlos Calhaz‑Jorge of the University of Lisbon. He also noted that further research is needed to prove causation.



The research team will now study hundreds of patients and link particle loads to embryo quality during <a href="https://my.clevelandclinic.org/health/treatments/22457-ivf" target="_blank" rel="noreferrer noopener">in vitro fertilization cycles</a>. Those correlations could supply the first direct human evidence beyond laboratory rodents.



They plan lifestyle questionnaires to test whether habits such as heavy bottled‑water use or microwaving food in plastic correlate with higher particle counts. The approach could convert abstract exposure theory into personal advice.



“Microplastics are just one variable in a complex equation,” said Dr. Gómez‑Sánchez. He urges moderation of plastic use rather than alarm. 



<h2 class="wp-block-heading" id="h-simple-habits-to-lower-exposure">Simple habits to lower exposure</h2>



Switching from plastic bottles to glass or stainless steel lowers ingestion because heat and time no longer leach particles from container walls. Replacing scratched nonstick pans can cut PTFE flakes in the diet.



Researchers advise skipping plastic cutting boards and using ceramic or bamboo instead, because knife action liberates shavings that cling to food. Letting take‑out cool before transferring it from polystyrene boxes also helps.



Air purifiers with HEPA filters capture airborne fibers shed by synthetic textiles, a step especially useful for nurseries. Regular vacuuming with a sealed system keeps particles from resuspending.



These tweaks are not foolproof, yet they come with side benefits like removing chemical additives that ride on plastic dust. They buy time while science sorts out the clinical stakes.



<h2 class="wp-block-heading" id="h-efforts-to-cut-human-plastics-pollution">Efforts to cut human plastics pollution</h2>



Public‑health researchers argue that personal choices alone cannot outrun a supply chain making more than a billion pounds of new plastic every day. 



Negotiators at the United Nations are hammering out a global treaty that could cap production and streamline recycling.



<a href="https://www.bc.edu/bc-web/schools/morrissey/departments/biology/people/faculty-directory/Phil-Landrigan.html" target="_blank" rel="noreferrer noopener">Dr. Philip Landrigan</a> of Boston College calls the treaty a once‑in‑a‑generation chance to protect human health, because curbing output remains the only sure way to slow microplastic fallout. He points to the emerging fertility data as evidence that time is short.



Whether lawmakers act or not, the science of sub‑visible plastic is moving fast thanks to sharper imaging tools and nanomechanical sensors. Studies that once took months now finish in days, filling the literature with fresh clues.



Every new dataset sharpens the same picture: plastics weather into dust, the dust goes everywhere, and living tissue keeps no closed doors. Eggs and sperm, it turns out, are no exception.



The study is published in the journal <a href="https://academic.oup.com/humrep#google_vignette" target="_blank" rel="noreferrer noopener">Human Reproduction</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 plastic particles found in human egg and sperm fluids

Tiny bits of plastic no wider than a human hair...

The sea spider, those spindly marine oddities that seem composed almost entirely of legs and claws, just given up their genetic secrets.



An international effort led by the <a href="https://www.univie.ac.at/en/">University of Vienna</a> and the <a href="https://www.wisc.edu/">University of Wisconsin–Madison</a> has delivered the first chromosome-level genome for Pycnogonum litorale, a species common in North Atlantic tide pools.



Stretching across 57 pseudo-chromosomes and paired with extensive developmental transcriptomes, the assembly offers an unprecedented look at how an arthropod can evolve such an extreme body plan. This includes a nearly vanishing abdomen and internal organs that spill far into its limbs.



<h2 class="wp-block-heading" id="h-mapping-the-sea-spider-genome">Mapping the sea spider genome</h2>



To achieve a genome this contiguous, the team combined long-read sequencing with Hi-C proximity data. Long reads captured tens of thousands of DNA bases at a stretch. This helped bridge the repetitive regions that routinely break short-read assemblies.



Hi-C, which measures how DNA folds inside the nucleus, then provided a “scaffolding” map that placed those long contigs into chromosomal order.



“The genomes of many non-canonical laboratory organisms are challenging to assemble, and Pycnogonum is no exception," said first author Nikolaos Papadopoulos, a zoologist at the University of Vienna. 



"Only the combination of modern high-throughput data sources made a high-quality genome possible. This can now serve as a stepping stone for further research.”



Because <a href="https://www.earth.com/news/surprising-breeding-behaviors-of-giant-sea-spiders-revealed/">sea spiders</a> are not standard lab animals, researchers collected specimens by hand, often prying them from kelp during low tide. They then rushed them back to the lab for nucleic acid extraction.



The payoff is a reference genome that joins spider, <a href="https://www.earth.com/news/fossil-reveals-the-first-ancestors-of-scorpions-and-spiders/">scorpion</a>, mite, and horseshoe crab assemblies on public databases. Yet it lacks the duplications that mark other arachnid genomes, making it a vital baseline for evolutionary comparisons.



<h2 class="wp-block-heading" id="h-vanished-gene-vanished-abdomen">Vanished gene, vanished abdomen</h2>



The analysis focused on Hox genes, key developmental regulators shared by animals from fruit flies to humans. One gene turned up missing: abdominal-A (abd-A).



In most arthropods, abd-A helps establish the rear-body segments that carry guts and reproductive organs. Sea spiders, with their virtually absent abdomens, appear to have dispensed with both the physical structure and its genetic architect.



“In arthropods, Hox genes play a central role in the correct specification of the different body segments, explained co-author Andreas Wanninger, who co-led the Vienna team. "In many other animal groups they are essential ‘master controllers’ during body plan development.” 



The disappearance of abd-A mirrors patterns seen in <a href="https://www.earth.com/news/how-mites-survived-without-sex-for-millions-of-years/">mites</a> and barnacles, two other arthropod groups that have independently shrunk or lost their hind segments.



<h2 class="wp-block-heading" id="h-sea-spiders-skipped-genome-doubling">Sea spiders skipped genome doubling</h2>



Spiders and scorpions carry extra copies of almost every gene, relics of an ancient whole-genome duplication that likely fueled innovations such as silk glands and complex venom cocktails.



P. litorale shows no sign of that event. Because sea spiders sit at the very base of the chelicerate lineage, the simplest explanation is that the duplication occurred later. It likely arose within the spider-scorpion branch, rather than in the common ancestor of all chelicerates.



That finding reshapes timelines for when gene families expanded and may help researchers pinpoint which duplications underlie spider-specific traits.



<h2 class="wp-block-heading" id="h-tools-for-growth-and-repair">Tools for growth and repair</h2>



Beyond raw sequence, the consortium generated RNA profiles from embryos and juveniles, capturing when each gene flicks on and off as new body segments form.



Those developmental datasets make the sea spider a promising model for studies of ancestral arthropod development, limb regeneration, and physiological resilience in cold, nutrient-poor seas.



Georg Brenneis, an expert in arthropod development at the University of Vienna, is a senior author of the study.



“From an evolutionary developmental perspective, sea spiders are very interesting: their mode of development may be ancestral for arthropods, but at the same time they boast multiple body plan innovations unique to themselves. Beyond this, they also possess remarkable regenerative abilities.” 



“Now that we have the genome and comprehensive datasets on gene activities during development, we can systematically study all of these aspects on the molecular level,” he said.



<h2 class="wp-block-heading" id="h-editing-limbs-and-trunk">Editing limbs and trunk</h2>



With <a href="https://www.earth.com/news/crispr-used-to-remove-extra-chromosomes-in-down-syndrome-and-restore-cell-function/">CRISPR</a> editing becoming feasible in marine invertebrates, investigators can now ask how the remaining sea spider Hox genes choreograph eight elongated walking legs and a tubular trunk. They can also explore how the animals quickly regrow lost appendages.



Comparative physiologists might search the genome for stress-response genes that let sea spiders thrive in icy fjords, while ecological genomics teams could examine how gene flow operates across their wide geographic ranges.



<h2 class="wp-block-heading" id="h-tracing-ancient-sea-spider-cousins">Tracing ancient sea spider cousins</h2>



Without the duplication, shared sea spider genes likely existed as single copies in the last common chelicerate ancestor.



Aligning those sequences will clarify where new venom toxins arose, when silk machinery evolved, and how immune genes diversified.



The genome also lets scientists investigate regulatory DNA - enhancers, promoters, and non-coding RNAs. These elements rewired a conventional arthropod blueprint into the minimalist sea spider form.



<h2 class="wp-block-heading" id="h-expanding-the-genomic-catalog">Expanding the genomic catalog</h2>



The authors envision expanding the catalog to additional sea spider species to test whether abd-A loss is universal. They also aim to map gains and losses of other developmental genes across the group’s 1,300 known species.



Such work could uncover genetic shortcuts to extreme morphological change - insights that extend far beyond any single marine arthropod.



For now, the P. litorale genome stands as a milestone: the first high-quality reference for the world’s most enigmatic chelicerates. It’s also a reminder that even life’s strangest branches follow molecular rules that genomics can finally reveal.



The study is published in the journal <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-025-02276-x">BMC Biology</a>.



Image Credit: Richard Lord/ <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode.en">CC BY-NC-SA 4.0</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.



-----

All legs, no guts: Sea spider genome stuns scientists

The sea spider, those spindly marine oddities that seem composed...

High in northern Peru, three frogs no bigger than a thumbprint have stepped out of anonymity and into the scientific spotlight. Their world is a maze of wet cliffs, dripping bromeliads, and wind‑scoured ridges where moss carpets the rocks.



“They’re <a href="https://www.earth.com/news/world-frog-day-2025-protecting-natures-tiny-guardians/">small</a> and unassuming, but these frogs are powerful reminders of how much we still don’t know about the Andes,” said Germán Chávez of the Center for Ornithology and Biodiversity (<a href="https://corbidi.org/">CORBIDI</a>). 



Chávez and his colleagues trekked those ridges between 2021 and 2024, often in freezing rain, to reach calling sites above 9,000 feet.&nbsp;



<h2 class="wp-block-heading" id="h-mountains-support-unique-frog-species">Mountains support unique frog species</h2>



The <a href="https://blog.pensoft.net/2025/06/27/hidden-gems-in-the-mist-three-new-frog-species-uncovered-in-northern-peru/cordillera-de-huancabamba-1/" target="_blank" rel="noreferrer noopener">Cordillera de Huancabamba</a> forms a natural break in the Andes, splitting watersheds and isolating species. 



Ecologists classify the region as a <a href="https://www.cepf.net/sites/default/files/tropicalandes_techsummary.pdf" target="_blank" rel="noreferrer noopener">biodiversity hotspot</a>, one of only thirty‑five on Earth where extraordinary endemism collides with severe habitat loss.



"The Cordillera de Huancabamba is not just a remote range - it's a living archive of biodiversity and cultural legacy," said Wilmar Aznaran. "And we've barely scratched the surface."



Isolation breeds novelty, and novelty fills the genus Pristimantis. With 619 described species, Pristimantis is now the most diverse <a href="https://www.earth.com/news/whistling-forest-frogs-recently-discovered-may-be-wiped-out-before-we-learn-about-them/">amphibian</a> genus on the planet.



The new frogs, Pristimantis chinguelas, P. nunezcortezi, and P. yonke, occupy different niches along the same ridge. One clings to cliff faces, one prowls leaf litter beside clear streams, and the smallest tucks itself deep inside tank bromeliads.



<h2 class="wp-block-heading" id="h-confirming-the-new-species">Confirming the new species</h2>



Night surveys began after dusk, when temperatures hovered near 50 °F and fog erased headlamp beams. Team members listened for faint “peep” notes that barely rose above dripping leaves. 



Finding a caller did not end the chase. Each frog had to be photographed, swabbed for DNA, measured, and released without harming delicate skin.



Back in Lima, the researchers compared mitochondrial 16S sequences. Genetic distances exceeded the three‑percent threshold herpetologists often use to flag separate <a href="https://www.earth.com/news/missing-frog-species-alsodes-vittatus-resurfaces-after-130-years/">species</a>, clinching the case for formal description.



<h2 class="wp-block-heading" id="h-many-amphibians-are-poorly-studied">Many amphibians are poorly studied </h2>



All three newcomers enter the IUCN books as <a href="https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-169-autumn-2024/4079-03-how-many-data-deficient-amphibians-are-threatened-iucn-red-list-assessments-for-amphibian-species-previously-classed-as-data-deficient" target="_blank" rel="noreferrer noopener">Data Deficient</a>, meaning scientists lack enough information to judge extinction risk. 



The label sounds neutral, yet recent reassessments show that roughly half of amphibians that start as Data Deficient later prove threatened.



Formal names unlock funding and legal tools that nameless creatures rarely receive. Conservation plans, environmental‑impact statements, and protected‑area budgets almost always hinge on a taxon’s standing in recognized databases.



<h2 class="wp-block-heading" id="h-indicators-of-climate-shifts">Indicators of climate shifts</h2>



The Cordillera de Huancabamba isn't just a biological goldmine, it’s wrapped in layers of folklore. In nearby villages, frogs are often seen as signs of rain or omens tied to agriculture and spiritual beliefs.



This cultural lens makes local communities key allies for conservation. When researchers name <a href="https://www.earth.com/news/frogs-lead-the-way-in-developing-new-antibiotics/">species</a> after regional icons or traditions, like P. yonke, they honor local identity and encourage stewardship.



Unlike most frogs, species in the <a href="https://www.inaturalist.org/taxa/64811-Pristimantis" target="_blank" rel="noreferrer noopener">Pristimantis genus</a> bypass the tadpole stage entirely. They hatch from eggs as fully formed froglets, ready to climb, hop, and call without ever entering water.



This reproductive shortcut allows them to thrive in places where standing water is rare or seasonal. It also makes them sensitive indicators of climate shifts and microhabitat changes in mountain ecosystems.



<h2 class="wp-block-heading" id="h-frog-species-in-fire-prone-habitats">Frog species in fire-prone habitats</h2>



Each frog occupies an area smaller than four square miles, hemmed in by crop fields and fire scars. Peru recorded about 10,400 wildfires in 2024, more than double its previous record, burning grasslands and cloud‑forest edges alike.



P. chinguelas calls from a road‑cut cliff where charred bamboo still smells of smoke. P. nunezcortezi shares a single stream corridor that now borders new potato plots.



P. yonke lives higher, inside bromeliads at roughly 9,800 feet, in what locals call the <a href="https://lacgeo.com/northern-andean-paramo" target="_blank" rel="noreferrer noopener">páramo</a>, a chilly grassland‑wetland mosaic perched above the treeline. 



Páramo vegetation stores water like a sponge, so every lost bromeliad weakens both the frogs and the human communities farther down‑slope.



“Exploring this area is more than fieldwork - it’s an immersion into wilderness, culture, and resilience,” said Karen Victoriano‑Cigüeñas.&nbsp;



"Many of these mountain&nbsp;ridges&nbsp;are isolated, with no roads and extreme terrain," noted Ivan Wong. "The weather shifts within minutes, and the steep cliffs make every step a challenge. It's no wonder so few scientists have worked here before. But that's exactly why there's still so much to find."



<h2 class="wp-block-heading" id="h-protecting-the-new-frog-species">Protecting the new frog species </h2>



No one has recorded the breeding calls of P. nunezcortezi or P. yonke, so females remain unverified. Diet, predators, and lifespan also remain mysteries for all three species.



Future expeditions will test whether the frogs persist on neighboring ridges or whether each ridge hosts its own micro‑endemic. 



Acoustic monitors and <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2019.2353" target="_blank" rel="noreferrer noopener">eDNA traps</a> could reveal silent populations hiding in moss tunnels or bromeliad tanks beyond the reach of hikers.



For now, the frogs depend on local goodwill. Community fire patrols, low‑impact grazing, and small protected micro‑reserves can buy time while researchers gather the missing data.



The study is published in the journal <a href="https://evolsyst.pensoft.net/article/148522/" target="_blank" rel="noreferrer noopener">Evolutionary Systematics</a>.



Image Credit: Germán Chávez et. al



-----



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.



-----

Three new frog species found in Peru face an uncertain future

High in northern Peru, three frogs no bigger than a...

Long before modern climate records began, a very different Earth existed - one where the icy edges of the Arctic were free of permafrost. This wasn't a minor shift. It was a Northern Hemisphere without frozen ground, stretching all the way to the Arctic Ocean. That past could be a preview of our future.



A new study shows that when Earth’s average temperature was just 4.5˚C warmer than it is today, the Asian continent had no permafrost - not even in its far north. This extent of climate warming is within the range we could reach again in the near future if emissions remain unchecked. 



Researchers from <a href="https://www.northumbria.ac.uk/">Northumbria University</a>, the University of Oxford, Bern University, and the Geological Surveys of Israel and the U.S. worked together to trace the ancient climate shift. They found their evidence in an unlikely place: inside caves beneath the Siberian tundra.



<h2 class="wp-block-heading" id="h-frozen-clues-hidden-underground">Frozen clues hidden underground</h2>



The team focused on cave formations known as <a href="https://www.earth.com/news/past-tipping-points-where-the-climate-changed-abruptly/">speleothems</a> - stalagmites and stalactites - which only grow when water can seep through the ground. In regions locked in permafrost, the soil stays frozen solid. That makes speleothem growth impossible. 



So, if these formations exist in caves beneath modern-day permafrost, it means the ground had to be thawed when they formed.



The researchers collected more than 60 mineral samples from caves in the Lena River delta, one of the coldest and most remote areas of northeastern Siberia. 



Using uranium-lead dating, a precise method for measuring tiny traces of radioactive decay, the team determined that the cave minerals had formed about 8.7 million years ago, during the late <a href="https://www.earth.com/news/fossil-site-in-australia-indicates-abundant-life-during-the-miocene/">Miocene</a> period.



This means the ground in that region was thawed at the time. Existing global temperature records show that Earth was 4.5˚C warmer than it is today.



<h2 class="wp-block-heading" id="h-the-fate-of-arctic-permafrost">The fate of Arctic permafrost</h2>



If Earth warms by that same amount again, the findings suggest that all but the deepest or highest-altitude permafrost would melt.



“Our findings provide direct quantitative evidence that if our <a href="https://www.earth.com/news/looking-to-earths-ancient-climate-to-predict-our-future/">climate</a> warms by 4.5˚C, the permafrost currently covering Canada, Siberia, Mongolia, America - in fact much of the Northern Hemisphere - would thaw. Only permafrost in high mountains and deep underground would survive," said Dr Sebastian Breitenbach of Northumbria University.



“This thaw would release billions of tonnes of <a href="https://www.earth.com/news/carbon-sinks-are-losing-their-ability-to-absorb-co2/">carbon</a> from the ground into the atmosphere, enhancing further warming. This finding is a real warning to us all. It shows how sensitive our climate system is and where we might be headed if we don't act to limit our climate emissions now.”



What makes this especially concerning is the sheer volume of carbon at risk. Scientists estimate that up to 130 billion tonnes are locked in today's permafrost. If that carbon is released as the ground thaws, it won't just add to the warming - it will accelerate it.



<h2 class="wp-block-heading" id="h-when-the-arctic-was-permafrost-free">When the Arctic was permafrost-free </h2>



“After much searching, we were fortunate to find well-preserved datable cave deposits in the heart of today’s <a href="https://www.earth.com/news/frozen-worm-comes-back-to-life-after-46000-years/">Siberian permafrost</a>,” said Dr Anton Vaks of the Geological Survey of Israel. 



“We can see that this present-day tundra region experienced a warmer climate, with mean annual global temperatures above 0°C and with permafrost-free conditions." 



According to Dr. Vaks, the evidence from the cave formations indicates that most of the Siberian landmass and likely similar regions in the Northern Hemisphere were permafrost-free when the deposits formed at Taba-Ba’astakh.



<h2 class="wp-block-heading" id="h-caves-as-climate-time-machines">Caves as climate time machines</h2>



Professor Gideon Henderson of the University of Oxford noted that caves are like time machines. 



“They capture a history of the climate and environment for millions of years of Earth history, which we can now read accurately using precise chemical analyses," said Henderson. 



"By doing so, we can predict the future, using past conditions as an analogue for the future to understand the impact of the warmer world we are heading into.



“This new study provides valuable new constraints on the magnitude of warming required to completely destroy permafrost in the northern hemisphere and remove one of the biggest continental stores of carbon.”



The full study was published in the journal <a href="https://www.nature.com/articles/s41467-025-60381-5">Nature Communications</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.



-----

Arctic permafrost vanished in the past - will it happen again?

Long before modern climate records began, a very different Earth...

Sexual behavior and preference - whether in humans or animals - isn’t random. It’s shaped early on, during fetal development, by how the brain responds to hormones like androgens (male sex hormones). 



This early exposure is known to affect many important adult traits. But there's been one big obstacle: how do you measure that influence without invasive methods?



<h2 class="wp-block-heading" id="h-rat-fingers-hint-at-sexual-behavior">Rat fingers hint at sexual behavior </h2>



Researchers from <a href="https://www.okayama-u.ac.jp/index_e.html" target="_blank" rel="noreferrer noopener">Okayama University</a> in Japan may have found an answer - by looking at rats’ fingers.



In a recent study, a team led by Professor <a href="https://loop.frontiersin.org/people/32931/overview" target="_blank" rel="noreferrer noopener">Hirotaka Sakamoto</a> and Dr. Himeka Hayashi found that a simple finger measurement - the ratio of the second digit to the fourth digit, known as 2D:4D - can predict sexual behavior and preference in rats.



This digit ratio has been studied in humans for years. On average, men tend to have a lower 2D:4D ratio than women, meaning their index fingers are shorter relative to their ring fingers. 



But surprisingly, there hasn’t been much research testing whether this holds true in other animals, nor has sexual proclivity been measured against 2D:4D ratio in humans or other animals. That’s what drew the researchers to rats.



<h2 class="wp-block-heading" id="h-understanding-the-2d-4d-ratio">Understanding the 2D:4D ratio</h2>



As stated, the 2D:4D ratio compares the lengths of your index finger (2D) and your ring finger (4D). 



To find it, just look at your right hand: if your ring finger is longer than your index finger, your 2D:4D ratio is considered low; if your index finger is about the same length or longer, your ratio is higher. 



Scientists have found that this ratio is set before you're born, influenced by the amount of <a href="https://www.earth.com/news/men-with-low-testosterone-have-a-higher-risk-of-mortality/">testosterone</a> and <a href="https://www.earth.com/news/study-suggests-menopause-can-be-delayed-or-even-eliminated/">estrogen</a> you were exposed to in the womb. 



In general, people with lower ratios were exposed to more testosterone, while higher ratios suggest more estrogen exposure.



This tiny finger difference has caught scientists’ attention because it seems to connect to traits like athletic ability, aggression, risk-taking, and even career interests. 



For example, some studies have found that people with lower 2D:4D ratios tend to do better in competitive sports or lean toward science and engineering fields. 



It’s also been tied to traits like <a href="https://www.earth.com/news/practicing-yoga-nidra-improves-sleep-memory-and-cognition/">cognition</a>, <a href="https://www.earth.com/news/personality-traits-are-not-strongly-inherited-from-parents/">personality</a>, <a href="https://www.earth.com/news/lack-of-sexual-satisfaction-linked-to-rapid-memory-decline/">sex drive</a>, and even <a href="https://www.earth.com/news/same-sex-sexual-behavior-linked-to-evolutionary-advantages-in-monkeys/">sexual orientation</a>.



But it’s not a rule - it’s just a pattern seen in large groups, not a way to predict someone’s future.



<h2 class="wp-block-heading" id="h-shorter-fingers-stronger-sex-drive">Shorter fingers, stronger sex drive</h2>



“We found that the 2D:4D ratio serves as a reliable biological marker for predicting sexual activity in rats,” said Sakamoto. 



“Rats with shorter second digits were not only more sexually active but also showed a clear preference for female scent.”



Building on their initial measurements, the team then ran mating trials to observe <a href="https://www.earth.com/news/science-behind-predicting-and-changing-human-behavior/">behavior</a>.



The results were clear. Male rats that ejaculated during their first encounter had shorter second digits compared to those that didn’t. 



These males also showed signs of higher sexual drive: they ejaculated more often, did so more quickly, and had stronger erectile function.



<h2 class="wp-block-heading" id="h-the-scent-of-sexual-behavior">The scent of sexual behavior </h2>



To go beyond behavior and look at preference, the researchers ran a simple but telling test. They placed male rats in a cage with two kinds of bedding: one scented by females, and the other by males.



All the male rats initially explored the male-scented bedding. But only those with shorter second digits stayed interested in the female-scented bedding. They sniffed, explored, and spent more time with it - indicating a clear sexual preference.



“While most studies have only linked the digit ratio to morphological sex differences, we noticed a surprising lack of research connecting digit ratio to the biological basis of sex itself - especially sexual activity and preference,” notes Hayashi. “This curiosity marked the start of our study.”



<h2 class="wp-block-heading" id="h-fingers-mirror-brain-wiring">Fingers mirror brain wiring</h2>



Beyond offering insight into rat behavior, the study points to a deeper question: how early hormone exposure shapes the brain in lasting ways.



Before birth, hormone exposure might wire our brains in ways that the 2D:4D ratio later reflects - potentially shaping complex behaviors like sexual orientation or emotional attachment.



“Our results suggest a profound link between the body and mind, with significant scientific and clinical implications,” said Sakamoto. “Simply examining our fingers could one day help identify aspects of our behavioral tendencies.”



The findings also offer a practical model for exploring biological questions that are difficult - or impossible - to study directly in humans. 



Because 2D:4D is also connected to cognitive traits and mental health conditions, this research could help explain sex-based differences in disorders like <a href="https://www.earth.com/news/toddler-screen-time-linked-to-atypical-sensory-behaviors/">autism</a>, <a href="https://www.earth.com/news/how-gut-bacteria-morganella-morganii-could-cause-depression-not-a-brain-disorder/">depression</a>, or attachment issues.



<h2 class="wp-block-heading" id="h-biology-is-not-the-whole-story">Biology is not the whole story</h2>



While the findings are compelling, they also raise important questions. For one, it’s still unclear how well results from rats translate to humans. 



Rats provide a useful model for controlled experiments, but human sexuality is influenced by many layers - cultural, social, psychological - that go far beyond biology.



The researchers also focused only on male rats. Future studies will need to explore whether similar patterns hold true for females, and how other factors like environment or stress interact with digit ratios to shape behavior.



Another key question is causation. Rats with shorter 2D:4D finger ratios tend to show more sexual activity and stronger preferences, but scientists aren’t yet sure whether the digit ratio drives this behavior - or if both stem from shared prenatal influences.



None of this takes away from the value of the study. But it highlights the importance of treating biological markers like 2D:4D as part of a much larger picture. 



The full study was published in the journal <a href="https://www.jstage.jst.go.jp/article/expanim/advpub/0/advpub_24-0159/_article" target="_blank" rel="noreferrer noopener">Experimental Animals</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.



-----

Does your finger length predict sexual behavior? A new study says yes

Sexual behavior and preference - whether in humans or animals...

For decades, space engineers have imagined shipping steel, glass, and concrete to other worlds so that future explorers can build homes on Mars and even further from Earth.



A new study led by Robin Wordsworth at <a href="https://seas.harvard.edu/">Harvard’s School of Engineering and Applied Sciences</a> turns that idea on its head. Rather than launching heavy construction kits, the team shows that habitats can, quite literally, grow themselves.



“If you have a habitat that is composed of <a href="https://www.earth.com/news/nature-inspired-solutions-new-bioplastic-dissolves-rapidly-in-water/">bioplastic</a>, and it grows algae within it, that algae could produce more bioplastic,” Wordsworth said. “So you start to have a closed-loop system that can sustain itself and even grow through time.”



<h2 class="wp-block-heading" id="h-turning-algae-into-architecture"><a></a>Turning algae into architecture</h2>



At the heart of the concept is Dunaliella tertiolecta, a type of hardy <a href="https://www.earth.com/news/green-algae-in-lake-erie-may-be-hiding-toxic-deadly-compounds/">green algae</a> already used on Earth for aquaculture and biofuel research.



The researchers conducted a series of lab tests where they 3-D printed dome-shaped chambers using polylactic acid (PLA), a common bioplastic fermented from plant sugars.



The walls were only a millimeter thick, but strong enough to hold liquid water even when the outside pressure fell to Mars-like levels of about 600 pascals - more than a hundred times lower than on Earth.



Inside these tiny “greenhouses,” the algae were bathed in carbon-dioxide-rich air, fed with artificial sunlight, and left to do what algae do best: photosynthesize, grow, and multiply.



After ten days, cell counts in low-pressure chambers nearly matched those in cultures grown at normal Earth pressure. This confirmed that life could flourish despite the thin atmosphere.



Light management was another hurdle. Mars receives plenty of visible sunlight, but its surface is bombarded by harmful ultraviolet rays. 



Tests showed that a single millimeter of PLA blocks all UV-C radiation and much of UV-A and UV-B while still letting through the red and blue wavelengths that <a href="https://www.earth.com/news/revealing-the-secrets-of-photosynthesis-through-pep/">photosynthesis</a> requires. In short, the plastic skin both protects and nourishes its green tenants.



<h2 class="wp-block-heading" id="h-self-growing-habitats-on-mars">Self-growing habitats on Mars</h2>



If the algae thrive, the cycle becomes self-amplifying. Researchers can convert extra biomass into fresh PLA, then print or mold it into new habitat walls.



A simple mass-balance analysis in the study suggests that with realistic conversion efficiencies, a foot-deep algae cultivation pond beneath each habitat could produce more than enough bioplastic to meet repair needs. 



This includes material to address routine weathering. Surplus production could even allow the living area to double every couple of years.



In theory, a single lander packed with starter cultures, nutrients, and a modest 3-D printer might seed an entire settlement that grows like coral over time. Operating at low pressure, the domes place far less stress on their walls than habitats built for full Earth pressure.



The team calculated that a one-millimeter PLA shell can comfortably withstand the loads. Reinforcement could come from additional biological materials, such as bacterial cellulose aerogels, which also provide insulation and help maintain plant-friendly temperatures between 10-30 °C (50-86 °F).



<h2 class="wp-block-heading" id="h-algae-domes-for-deep-space">Algae domes for deep space</h2>



Although the experiments targeted Mars, similar biomaterial bubbles could help researchers design life-support systems for the Moon, free-floating space stations, or even harsh environments on Earth.



Wordsworth notes that a later phase of the project will test whether the same strategy can function in a complete vacuum. This is essential for lunar use and will test whether the algae-PLA loop can run without outside resources after kickoff.



“The concept of biomaterial habitats is fundamentally interesting and can support humans living in space,” he said. The progress in off-world <a href="https://www.earth.com/news/scientists-urgent-plea-sustainable-climate-solutions-save-earth-humanity/">sustainability</a> almost invariably “has spinoff benefits for sustainability technology here on Earth as well.”



One immediate benefit is the potential use of the domes as low-energy bioreactors. Unlike conventional indoor farms that rely on electric lamps, algae inside translucent shells harvest natural sunlight. That eliminates a major power drain - a critical advantage on distant worlds where every watt matters.



<h2 class="wp-block-heading" id="h-surviving-mars-extremes">Surviving Mars’ extremes</h2>



Of course, challenges remain. Mars swings through dramatic temperature cycles, and liquid water will freeze solid without extra heating or insulation. 



Perchlorate salts in Martian dust are toxic to many organisms, so engineers will need robust filtration or genetically tuned microbes.



Gas exchange will also need to be balanced. PLA walls allow carbon dioxide to seep in and oxygen to seep out, but water vapor escapes the same way, risking desiccation unless clever humidity controls are included.



Shielding human occupants from <a href="https://www.earth.com/news/deep-space-cosmic-rays-from-supernova-sparked-rapid-earth-evolution/">cosmic radiation</a> also demands thicker or layered shells, perhaps combining PLA with locally mined regolith.



Finally, the team is keen to move from flask-scale proofs to pilot-scale structures that people can walk into. The future domes could pair the algae chambers with silica-aerogel skylights. This technology, developed by Wordsworth’s group, captures sunlight while trapping heat to create temperate oases on an otherwise frigid plain.



<h2 class="wp-block-heading" id="h-bioplastic-homes-grown-by-algae">Bioplastic homes grown by algae</h2>



The broader message of the study is that biology can be both passenger and partner in humanity’s push beyond Earth.



If algae build walls and microbes recycle plastic, habitats could grow and repair themselves instead of being shipped from Earth. Instead, they become living, self-healing ecosystems.



That vision aligns with <a href="https://www.nasa.gov/">NASA</a>’s growing interest in in-situ resource utilization and with wider efforts to craft sustainable, circular economies at home.



In other words, the green slime that clings to your fish tank might one day help roof the first Martian village - and teach us a few lessons about building lighter, cleaner, and smarter back on the pale blue dot.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/sciadv.adp4985">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.



-----

Bioplastic bubbles made with algae could sustain life on Mars

For decades, space engineers have imagined shipping steel, glass, and...

Ants, with their unique genes, outnumber people by roughly 2.5 million to one. Their combined dry mass, about 12 million tons of carbon, rivals one‑fifth of humanity’s weight on land.



An international research team has compared 163 ant genomes to show how these <a href="https://www.earth.com/news/swarm-intelligence-ants-can-anticipate-obstacles-and-plan-ahead/">insects</a> turned cooperative living into an evolutionary engine. They reshuffled DNA while guarding key caste <a href="https://www.pnas.org/doi/10.1073/pnas.2201550119" target="_blank" rel="noreferrer noopener">genes</a> for more than 100 million years.



<h2 class="wp-block-heading" id="h-genetic-clues-to-colony-life">Genetic clues to colony life</h2>



Dr. Lukas Schrader of the <a href="https://www.uni-muenster.de/en/" target="_blank" rel="noreferrer noopener">University of Münster</a> helped coordinate the <a href="https://www.cell.com/cell/fulltext/S0092-8674(25)00617-8" target="_blank" rel="noreferrer noopener">project</a> and still sounds amazed by its scope.



<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC2665839/" target="_blank" rel="noreferrer noopener">Charles Darwin</a> once fretted over sterile workers, calling them a “special difficulty” because natural selection seemed unable to favor individuals that never breed. 



Inclusive‑fitness theory, formalized in 1964, solved the logic by showing that workers spread their genes by helping sisters.



The new data add genetic proof to that idea: worker‑specific <a href="https://www.earth.com/news/how-many-ants-live-on-earth-at-any-point-in-time-total-number-is-astounding/">gene</a> clusters stayed almost identical across lineages, hinting that any mutation hurting brood care was swiftly purged.



<h2 class="wp-block-heading" id="h-ant-colonies-behave-like-bodies">Ant colonies behave like bodies</h2>



Biologists label an ant colony a superorganism because its members behave like cells of one body. 



The new <a href="https://www.cell.com/cell/fulltext/S0092-8674%2825%2900617-8" target="_blank" rel="noreferrer noopener">dataset</a> spans army ants with millions of workers, species such as Camponotus japonicus whose queens dwarf their tiniest laborers more than 100‑fold, and even parasites that have lost workers altogether.



Researchers sequenced 145 species from 25 countries and folded in 18 earlier genomes to reach chromosome‑level quality for 17 of them. That’s no small feat when many ants are smaller than a comma.



“The publication is a milestone in our understanding of the molecular and genetic foundations of ants and probably also other social <a href="https://www.earth.com/news/how-ants-could-help-stop-the-tree-killing-lanternfly/">insects</a> such as honeybees,” said Schrader.



Across the tree, queen and worker blueprints sit side by side. Yet workers never hatch reproductive organs because development is rerouted by hormones and gene‑regulation circuits embedded in the shared DNA.



<h2 class="wp-block-heading" id="h-ants-keep-critical-survival-genes">Ants keep critical survival genes</h2>



The study tracked <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/synteny" target="_blank" rel="noreferrer noopener">synteny</a>, the order of genes along a chromosome. Whole blocks had flipped, fused, or fractured at a rate up to four times that seen in vertebrates. Ant groups with the fastest breakage spawned the most species.



Even so, 970 tiny gene clusters, street blocks in the genetic city, remained frozen across 80 percent of species. Many code for metabolism and caste traits, suggesting that breaking them would cripple <a href="https://www.earth.com/news/paleontologists-found-the-oldest-ant-species-on-earth-113-million-years-old-with-scythe-like-jaws/">colony</a> function.



One conserved block houses two <a href="https://www.sciencedirect.com/topics/neuroscience/vitellogenin" target="_blank" rel="noreferrer noopener">vitellogenin genes</a> vital for queen egg yolk and sits unchanged in 148 genomes. Another links fatty‑acid enzymes to worker‑biased expression, underlining how diet and labor intertwine.



Holding those modules steady while the surrounding landscape rearranged let ants explore new lifestyles without losing the caste machinery that keeps colonies alive.



<h2 class="wp-block-heading" id="h-hormones-decide-jobs-and-stability">Hormones decide jobs and stability</h2>



A single molecule can tip a larva toward royalty or toil. <a href="https://www.pnas.org/doi/10.1073/pnas.2406999121" target="_blank" rel="noreferrer noopener">Juvenile hormone</a> has long been that switch, and gene copies for the enzyme <a href="https://www.pnas.org/doi/10.1073/pnas.2134232100" target="_blank" rel="noreferrer noopener">JHAMT</a> rise in species with extreme queen‑worker size gaps.&nbsp;



Insulin and <a href="https://www.science.org/doi/10.1126/science.abm8767" target="_blank" rel="noreferrer noopener">MAPK signaling</a> join the act. In the jumping ant Harpegnathos, blocking MAPK with the drug trametinib makes workers grow larger, echoing lab findings that this pathway expands ovaries when workers become egg‑laying gamergates.&nbsp;



The new comparison shows MAPK genes under intensified selection in lineages where workers can still replace a queen, but relaxed selection where caste roles are rock‑solid. 



That fits the idea that plastic colonies need fine hormonal tuning, while rigid ones lock their switches.



Hormone receptors for juvenile hormone and insulin sit inside conserved synteny islands. This hints that the entire endocrine toolkit rode through deep time as a connected package.



<h2 class="wp-block-heading" id="h-ant-genes-shift-with-colony-size">Ant genes shift with colony size</h2>



Bigger colonies and steeper queen‑worker dimorphism marched together in evolution; both correlate with trails, trophallaxis, and worker polymorphism. 



Genes tied to brain development, such as <a href="https://www.genecards.org/cgi-bin/carddisp.pl?gene=GCM1" target="_blank" rel="noreferrer noopener">GCM</a> and the <a href="https://www.ncbi.nlm.nih.gov/gene/37892" target="_blank" rel="noreferrer noopener">muscarinic receptor mAChR‑A</a>, show worker‑type biased activity and signs of adaptive change in species sporting soldiers beside tiny foragers.



Where workers lost ovaries altogether, selection on oogenesis genes like otu relaxed, but those same genes stay under pressure in species whose workers can still lay male eggs.



Social parasites flip the pattern. Workerless inquilines shed odorant‑receptor genes and rack up chromosomal breaks, mirroring their narrow ecological niche and tiny population sizes.



<h2 class="wp-block-heading" id="h-ant-genes-explain-social-evolution">Ant genes explain social evolution</h2>



Many themes, hormonal control, preserved gene neighborhoods, break‑induced innovation, also shape honeybees, wasps, and higher termites. Ants simply had a 150‑million‑year head start, offering a living time machine for social evolution.



Knowing which genes stay linked during caste splits could aid synthetic‑biology efforts that aim to engineer division of labor in microbes or even tissues.



The study also reminds us that nature can be both flexible and conservative: colonies reinvent chromosome layouts yet keep critical circuits intact, a balance worth emulating in adaptive technologies.



Ants may be tiny, but their genomes read like manuals on how cooperation rewires life. Future research will test whether the same genetic choreography repeats whenever individual interests yield to collective success.



The study is published in the journal <a href="https://www.cell.com/cell/fulltext/S0092-8674(25)00617-8" target="_blank" rel="noreferrer noopener">Cell</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.



-----

Ant genes show how evolution created perfect teamwork

Ants, with their unique genes, outnumber people by roughly 2.5...

Tired,Mother,Feeding,Milk,Bottle,To,Newborn,Baby,While,Looking

Nighttime parenting has always been wrapped in cultural beliefs and assumptions. One of the most common claims is that women are biologically wired to wake up faster than men when a baby cries.



This belief often shapes how society views parenting roles. Mothers are expected to respond quickly, while fathers are assumed to sleep through the noise.



But a new study from <a href="https://international.au.dk" target="_blank" rel="noreferrer noopener">Aarhus University</a> challenges this long-held idea. The research reveals surprising findings that question the biological basis of such assumptions.



Rather than relying on stereotypes, the study uncovers more nuanced truths about sleep, caregiving, and gender roles. These insights not only shift how we think about nighttime parenting but also point to broader social patterns.



<h2 class="wp-block-heading" id="h-crying-wakes-both-parents">Crying wakes both parents</h2>



The researchers conducted two separate experiments to test how men and women respond to nighttime sounds.



In the first study, they recruited 142 adults without <a href="https://www.earth.com/news/baby-talk-may-explain-what-sets-humans-apart-from-apes/">children</a>. These participants took part in sleep experiments designed to measure their responses to very quiet sounds.



“Contrary to popular media portrayals, our male participants did not sleep through baby crying," said Professor Christine Parsons from the Department of Clinical Medicine. "We had a lot of variability on how people woke up to the sounds during the experiment, and a lot of overlap between our male and female participants,”



The findings showed that women were only slightly more sensitive to whisper-level noises. Women were about 14 percent more likely to wake up to very soft sounds, whether from a baby’s cry or a regular alarm.



Once the sound volume increased, both men and women reacted almost the same way. This suggests that the difference in how men and women wake up is much smaller than commonly believed.



<h2 class="wp-block-heading" id="h-mother-s-night-duties-still-heavier">Mother’s night duties still heavier</h2>



While <a href="https://www.earth.com/news/sleep-debt-new-parents-lose-two-months-of-sleep-in-a-babys-first-year/">sleep</a> sensitivity may not differ much, parenting responsibilities still show a large gap.



In the second study, researchers focused on real-life parenting situations. They studied 117 first-time parents in Denmark, asking them to track their nighttime caregiving over a week.



“The results showed that mothers were three times more likely to handle nighttime infant care than fathers," said PhD student Arnault Quentin-Vermillet, co-authored of the study. 



"Our mathematical modeling showed that the large difference in nighttime care cannot be explained by the minor differences we observed in sound sensitivity between men and women.” 



These findings show a clear gap between biology and caring for crying babies at night. Women, in practice, bear the larger share of nighttime childcare despite the minor difference in sound sensitivity.



<h2 class="wp-block-heading" id="h-experience-shapes-night-response">Experience shapes night response</h2>



If sound sensitivity does not fully explain this gap, then what does? The researchers suggest that social structures play a stronger role in shaping these patterns.



“We think that there are several factors that explain our results, probably intertwined," said Parsons. 



"First, mothers generally take maternity leave before fathers take paternity leave. Mothers then gain more experience in soothing their <a href="https://www.earth.com/news/singing-to-babies-is-a-powerful-way-to-boost-their-mood/">baby</a> early on than fathers. Second, when mothers are breastfeeding at night, it might make sense for fathers to sleep through.”



Such practices often continue even after the initial postpartum period, reinforcing caregiving habits. Early caregiving experience can shape who responds to the baby at night, often leaving mothers as the primary caregivers.



<h2 class="wp-block-heading" id="h-parenting-shifts-and-crying-babies">Parenting shifts and crying babies</h2>



This study contributes to the broader conversation about parenting equality. It raises important questions about how much of caregiving is driven by biology versus social expectations.



Policies in Denmark have recently changed to offer longer, earmarked <a href="https://www.earth.com/news/how-paternity-leave-changes-parenting-dynamics/">paternity leave</a>. Fathers can now take 11 weeks of paid leave, compared to the earlier two-week allowance.



Such policy shifts could help balance caregiving responsibilities. Fathers may gain more hands-on experience, which could gradually change nighttime caregiving dynamics.



The researchers hope this study encourages further investigations into how parents adapt during the early stages of child-rearing. They also highlight the need to study how sleep patterns, caregiving habits, and hormone changes interact over time.



<h2 class="wp-block-heading" id="h-cultural-myths-break-down">Cultural myths break down</h2>



This research invites a shift away from long-standing stereotypes about motherhood and fatherhood. It shows that minor biological differences cannot fully explain caregiving patterns.



Instead, social practices, work policies, and early parenting experiences seem to shape who wakes up at night.



By questioning popular assumptions, the study encourages a more balanced and realistic view of parenting and the care of crying babies.



As families grow more diverse and parental roles evolve, understanding these dynamics becomes even more crucial. The findings from Aarhus University mark a step toward a fairer, more informed discussion about parenting and sleep.



The study is published in the journal <a href="https://psycnet.apa.org/doiLanding?doi=10.1037%2Femo0001478" target="_blank" rel="noreferrer noopener">Emotion</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.



-----

Despite widespread beliefs, crying babies also wake dads, but moms do get up more often

Nighttime parenting has always been wrapped in cultural beliefs and...

People often feel stressed. Many don’t have time to go outside and relax. Cities keep growing, and virtual access to natural spaces feels more common while real ones feel far away. 



In Japan, people use forest bathing to reduce stress. They call it Shinrin Yoku. It simply means spending quiet time in a forest. No phones, no distractions - just <a href="https://www.earth.com/news/urban-green-spaces-are-urgently-needed-across-the-global-south/">nature</a>.



Researchers wanted to test something different. Can forest bathing work through a screen? Can people feel calmer by using virtual reality instead of going outside? They set up a study to find out.



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



The researchers wanted to create a very realistic virtual forest experience. To do this, they filmed a 360° VR video in Sonnenberg <a href="https://www.earth.com/news/urban-gardens-help-cities-fight-climate-change/">nature</a> reserve. This forest is the largest Douglas fir forest in Europe.



The team didn’t stop at just recording the scenery. They also captured all the natural sounds, like the wind blowing through the trees and birds singing. 



On top of that, the researchers added the scent of Douglas fir essential oils to match what someone would actually smell in the forest. Participants in the study had different experiences based on the setup.



Some people got the full experience. They saw the forest video through VR headsets. At the same time, they heard the forest sounds and smelled the fir scent. This gave them a complete, rich, multisensory experience.



Other participants only experienced one sense at a time. Some only watched the forest video without sound or scent. Others only listened to the forest sounds, while some only smelled the scent without visuals or audio.



When the researchers tested hearing or scent alone, they kept the visuals simple and plain. They wanted to avoid flashy images or colors that could distract people. The goal was to focus only on one sense at a time for clear results.



<h2 class="wp-block-heading" id="h-virtual-forest-improved-mood">Virtual forest improved mood</h2>



The researchers didn’t just let people jump into the virtual <a href="https://www.earth.com/news/living-green-spaces-boosts-bone-density-reduces-osteoporosis/">forest</a>. First, they showed participants stressful images to raise their stress levels.



Once people felt stressed, they put on VR headsets. They then experienced one of four versions of the forest. Some got the full version. Others experienced just one sense.



People who used sight, sound, and scent together felt the biggest mood boost. They also felt more connected to nature.



The single-sense versions helped too but not as much. Some participants even showed slight improvements in working memory. This type of memory helps with short-term thinking and tasks.



Still, the researchers said more studies are needed. They explained that the results may not apply to everyone.



Study lead author Leonie Ascone is a researcher in the Neuronal Plasticity working group at the University Medical Center Hamburg-Eppendorf (<a href="https://www.uke.de/english/index.html" target="_blank" rel="noreferrer noopener">UKE</a>).



"We can already say that digital nature experiences can absolutely produce an emotional effect - even if they don’t replace actual <a href="https://www.earth.com/news/earth-day-2025-innovation-takes-the-lead-in-environmental-action/">nature</a>," noted Ascone.



<h2 class="wp-block-heading" id="h-vr-nature-in-busy-everyday-places">VR nature in busy everyday places</h2>



Virtual nature won’t replace real forests, but it may help in other spaces. Simone Kühn, who led the research, is director of the <a href="https://www.mpib-berlin.mpg.de/research/research-centers/environmental-neuroscience">Center for Environmental Neuroscience</a> at the Max Planck Institute for Human Development



Kühn believes VR nature could help people in stressful environments. "Especially in places with limited access to nature - such as clinics, waiting areas or urban interiors - multisensory VR applications or targeted nature staging could support mental well-being."



"The images, sounds and scents of nature offer previously underestimated potential for improving mood and mental performance in everyday situations."



The research suggests that nature videos can even reduce pain in some cases. Now, Kühn sees more possibilities. Virtual nature could help people in hospitals, offices, and city spaces. It might make everyday life feel less tense.



<h2 class="wp-block-heading" id="h-nature-still-works-even-virtually">Nature still works, even virtually</h2>



This study gives one simple message - nature affects people in a positive way. Even when nature appears on a screen, it still changes how people feel. The researchers saw clear improvements in mood and connection to nature, even though participants never left the room.



But it’s important to be realistic. Virtual forest bathing is not a perfect solution. It cannot fully replace being outdoors. Real forests offer more than just sights, sounds, and smells. There is fresh air, physical movement, and other factors that VR cannot copy.



Still, virtual forest bathing can help people who cannot easily go outside. People in hospitals, city apartments, or busy workplaces often have no access to real forests. For them, even a short virtual nature experience may reduce stress and lift their mood.



The study is published in the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0272494425001203?via%3Dihub" target="_blank" rel="noreferrer noopener">Journal of Environmental Psychology</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.



-----

Virtual forest bathing can reduce stress and improve mood

People often feel stressed. Many don’t have time to go...

Milk, a staple in countless diets worldwide, now faces an uncertain future. As climate change accelerates, its effects are being felt far beyond melting glaciers and rising seas. 



One of the most troubling consequences is unfolding silently in dairy farms - where heat is becoming an ever-present threat.



Heat stress in cows is not new. Dairy farmers have long dealt with summer slumps in <a href="https://www.earth.com/news/new-study-shows-that-dairy-milk-cheese-consumption-improves-gut-biodiversity-health/">milk</a> production. But today's climate shifts are not just occasional hurdles. They are becoming regular, intense, and prolonged. 



Scientists now warn that the future of milk production could face irreversible changes, with major impacts on food supplies and farmer livelihoods.



A recent study offers deep insight into this challenge. It reveals that extreme heat reduces milk yields by up to 10 percent, and cooling systems are only partly effective. The results highlight the limits of technology in fighting nature’s heat waves.



<h2 class="wp-block-heading" id="h-extreme-heat-is-cutting-milk-production">Extreme heat is cutting milk production</h2>



The study examined 320 million daily records from Israeli <a href="https://www.earth.com/news/drinking-raw-milk-health-hazard-pasteurization-important/">dairy</a> farms over 12 years. It shows that extreme humid heat reduces milk yield by up to 10 percent. These effects linger beyond 10 days.



“Climate change will have wide-ranging impacts on what we eat and drink, including that cold glass of milk,” said Eyal Frank, an assistant professor at the <a href="https://harris.uchicago.edu" target="_blank" rel="noreferrer noopener">Harris School of Public Policy</a>.



Even farms with the best technology could only offset less than half of these losses.



<h2 class="wp-block-heading" id="h-israeli-farms-offer-global-insights">Israeli farms offer global insights</h2>



Israel's dairy sector uses advanced technology and operates under government-controlled <a href="https://www.earth.com/news/dairy-farms-can-join-the-climate-fight-by-trapping-methane/">milk</a> prices. 



The researchers gathered data from more than 130,000 cows. They also surveyed 306 farmers on their heat mitigation strategies, including cooling technologies.



“The dairy industry in Israel is a good testbed because farms are scattered throughout the country and experience a wide range of temperatures and humidity that represent conditions for top milk producing countries around the world,” noted Ram Fishman, associate professor of Public Policy at <a href="https://english.tau.ac.il" target="_blank" rel="noreferrer noopener">Tel Aviv University</a>.



<h2 class="wp-block-heading" id="h-humid-heat-causes-sharp-milk-declines">Humid heat causes sharp milk declines</h2>



The study shows milk yields fall sharply when wet-bulb temperatures exceed 26°C (78.8°F). Wet-bulb temperature captures both heat and humidity, making it more accurate for gauging heat stress.



When cows face these <a href="https://www.earth.com/news/raw-milk-could-carry-deadly-flu-viruses-for-days/">conditions</a>, production drops by nearly 10 percent. It also takes more than 10 days for milk output to recover.



Cooling systems, such as fans and sprinklers, help but lose effectiveness as temperatures rise.



<h2 class="wp-block-heading" id="h-cooling-helps-but-only-partially">Cooling helps, but only partially</h2>



Cooling equipment can cut losses by about half on moderately hot days. However, on hotter days, this protection weakens.



Farms typically recoup cooling costs within 1.5 years, making it a profitable, though incomplete, solution.



“Dairy farmers are well aware of the negative impacts that heat stress has on their herds, and they use multiple forms of adaptation,” says Ayal Kimhi, associate professor at the <a href="https://en.huji.ac.il" target="_blank" rel="noreferrer noopener">Hebrew University of Jerusalem</a>.



<h2 class="wp-block-heading" id="h-heat-damage-to-milk">Heat damage to milk </h2>



The researchers discovered that heat’s effects on milk production can last longer than previously believed.



Ten consecutive days of humid heat can reduce yields by up to 26 percent. These prolonged impacts suggest that heat stress accumulates, making recovery slow and difficult.



Some farms also shift calving periods and change feeding schedules to reduce heat impacts. These additional tactics offer slight benefits. Farms using both calving and feed adjustments showed better resilience during extreme heat.



Still, the researchers found that these methods offer limited protection compared to the scale of the problem.



<h2 class="wp-block-heading" id="h-future-heat-will-worsen-milk-shortages">Future heat will worsen milk shortages</h2>



The research models future scenarios for major dairy-producing countries. Without cooling, these nations may lose up to 4 percent of their annual milk production by mid-century.



India, Pakistan, and Brazil face some of the largest losses. Cooling can reduce some of the impact, but not eliminate it.



The study also highlights that even with cooling, losses persist in countries like the United States and China.



<h2 class="wp-block-heading" id="h-rethinking-dairy-adaptation">Rethinking dairy adaptation</h2>



The researchers found a clear trade-off. Higher-producing cows suffer more from heat stress.



Milk losses are highest during early lactation stages and among older cows that produce more milk. This trade-off raises concerns about the long-term sustainability of high-output dairy systems.



The study raises questions about current dairy farming practices. Full indoor housing can reduce heat exposure but introduces new problems, like stress from confinement.



“Our research underscores the value and the limitations of cooling technologies and other efforts taken by dairy farmers to adapt to climate change,” said Claire Palandri, a postdoctoral scholar at the Harris School of Public Policy.



Palandri urges policymakers to explore alternative ways to ease heat stress on cows, such as reducing confinement or allowing more natural behaviors, to protect milk production in a warming world.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/sciadv.adw4780" 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.



-----

Milk prices are rising with the heat around the world due to production issues

Milk, a staple in countless diets worldwide, now faces an...

For years, bacteria dominated gut health research. Now, the gut virome is gaining attention as a major player in health and disease. Bacteriophages, which are viruses that infect <a href="https://www.earth.com/news/scientists-think-they-found-two-key-bacteria-that-cause-multiple-sclerosis/">bacteria</a>, make up around 90% of the gut virome.



Though small in biomass, they outnumber bacteria by up to tenfold. These tiny viruses shape microbial communities, influence immunity, and affect gut health.



A landmark review published recently in Precision Clinical Medicine reveals how the gut virome links to diseases like inflammatory bowel disease (<a href="https://www.cdc.gov/inflammatory-bowel-disease/about/index.html" target="_blank" rel="noreferrer noopener">IBD</a>), <a href="https://www.earth.com/news/colonoscopy-vs-stool-tests-doctors-found-out-which-is-better-at-detecting-cancer/">colorectal cancer</a>, and Clostridium difficile infection (<a href="https://my.clevelandclinic.org/health/diseases/15548-c-diff-infection" target="_blank" rel="noreferrer noopener">CDI</a>).



<h2 class="wp-block-heading" id="h-gut-s-virome-changes-across-life-stages">Gut's virome changes across life stages</h2>



The gut virome changes constantly throughout life. Infants show high <a href="https://www.earth.com/news/bacteria-that-eat-forever-chemicals-discovered-in-contaminated-soil/">diversity</a> in gut bacteriophages (also called phages), which is shaped by birth method, diet, and antibiotic exposure.



As individuals grow, diet and hormones refine the virome. In adults, phages and bacteria form a stable, <a href="https://www.nature.com/articles/s41579-021-00536-5" target="_blank" rel="noreferrer noopener">balanced community</a>.



However, aging shifts this balance. Older adults show more lysogenic phages, which integrate into bacterial genomes and potentially alter metabolism and immune interactions.



<h2 class="wp-block-heading" id="h-diet-and-environment-shape-the-virome">Diet and environment shape the virome</h2>



Diet greatly <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9455721/" target="_blank" rel="noreferrer noopener">influences</a> the virome. High-fiber diets support beneficial phages by encouraging helpful bacteria. Western diets, rich in fat and sugar, promote harmful <a href="https://www.earth.com/news/some-bacteria-breathe-by-creating-electricity/">phages</a>.



Urbanization reduces exposure to natural viruses. Studies show that rural diets which are rich in fiber boost gut virome diversity.



Host genetics and immunity also play roles. Genetic variants can affect viral detection and clearance. Immune defenses, like <a href="https://my.clevelandclinic.org/health/treatments/interferons" target="_blank" rel="noreferrer noopener">interferons</a> and <a href="https://www.immunology.org/public-information/bitesized-immunology/receptors-molecules/immunoglobulin-iga" target="_blank" rel="noreferrer noopener">IgA</a>, keep the virome balanced.



However, immune dysfunction can trigger viral imbalances, worsening conditions like HIV and gut inflammation.



<h2 class="wp-block-heading" id="h-viruses-and-bacteria-interacting">Viruses and bacteria interacting</h2>



Viruses, including phages, along with bacteria and fungi form a complex and dynamic ecosystem in the gut. The components interact in positive and negative ways, thus affecting host metabolism, immune regulation and resistance to disease. 



The gut virome plays a crucial regulatory role in these intricate interactions. Phages interact with bacteria through lytic, lysogenic, and budding cycles, which regulate bacterial populations and gene flow. 



In a form of microbial arms race, the bacteria defend against phages using <a href="https://www.earth.com/news/crispr-used-to-remove-extra-chromosomes-in-down-syndrome-and-restore-cell-function/">CRISPR systems</a> and the phages evolve escape mechanisms.



Some phages even boost bacterial metabolism and biofilm formation, affecting disease risk. For instance, phages can transfer genes that enhance bacterial survival in acidic conditions.



<h2 class="wp-block-heading" id="h-virome-s-influence-on-immunity">Virome’s influence on immunity</h2>



The virome affects gut immunity deeply. <a href="https://www.earth.com/news/when-bacteria-get-hungry-they-turn-on-each-other/">Phages</a> can anchor to gut mucus and form a protective barrier. They also shape our own <a href="https://www.ncbi.nlm.nih.gov/books/NBK459471/" target="_blank" rel="noreferrer noopener">T and B cell</a> activity and regulate macrophages. In addition, viruses that infect eukaryotic cells affect immune pathways and maintain gut balance.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/07/virome_microbiome_human-gut_graphic_credit-PCM_1m.jpg"><img src="https://www.earth.com/wp-content/uploads/2025/07/virome_microbiome_human-gut_graphic_credit-PCM_1s.webp" alt="This infographic illustrates four major therapeutic approaches—fecal microbial transplantation (FMT), phage therapy, dietary interventions, and probiotics/prebiotics—that aim to restore gut health by modulating the microbiome and virome. Each strategy offers unique methods, benefits, and challenges in managing gastrointestinal disorders such as IBD, CRC, and CDI, highlighting the growing potential of virome-informed precision medicine. Credit: Precision Clinical Medicine" class="wp-image-1976450"/></a><figcaption class="wp-element-caption">This infographic illustrates four major therapeutic approaches—fecal microbial transplantation (FMT), phage therapy, dietary interventions, and probiotics/prebiotics—that aim to restore gut health by modulating the microbiome and virome. Each strategy offers unique methods, benefits, and challenges in managing gastrointestinal disorders such as IBD, CRC, and CDI, highlighting the growing potential of virome-informed precision medicine. Click image to enlarge. Credit: Precision Clinical Medicine</figcaption></figure>



However, infections and antibiotics can disrupt this harmony and lead to inflammation. Phages can trigger TLR9 pathways, causing excessive immune responses such as those linked to IBD.



<h2 class="wp-block-heading" id="h-virome-s-role-in-disease">Virome’s role in disease</h2>



Imbalances in the gut virome have been linked to several gut diseases. In IBD, specific phages become abundant and worsen inflammation.



Certain groups of phages (such as Caudovirales) amplify immune responses, while norovirus and rotavirus can damage the gut lining. Viral imbalances are also common in IBS and CDI.



In colorectal cancer, phages and eukaryotic viruses like HPV and JC virus (polyomavirus) appear more often. They may promote tumor growth by altering bacterial communities and gene expression.



Studies suggest that some phages directly influence cancer risk by promoting biofilms and transferring harmful genes.



<h2 class="wp-block-heading" id="h-virus-based-treatments">Virus-based treatments</h2>



Several therapies now explore the virome’s potential to treat certain diseases or conditions. Fecal microbiota transplantation (FMT) restores gut balance and reduces inflammation in IBD and CDI.



FMT works not only by shifting bacteria but also by transferring beneficial phages. Studies show that donor phages often align quickly with recipients and promote recovery.



Phage therapy, which uses viruses to kill specific bacteria, is another approach that is gaining traction. It can reduce harmful microbes while preserving beneficial ones.



Researchers have created phage cocktails that target specific gut pathogens like E. coli and Klebsiella pneumoniae, and this approach has had promising results in animal models.



<h2 class="wp-block-heading" id="h-diet-as-a-tool-to-reshape-the-virome">Diet as a tool to reshape the virome</h2>



Dietary strategies also reshape the virome. High-fiber diets boost beneficial phages and support bacterial diversity.



Whey protein has shown potential in managing Crohn’s disease by improving phage-bacteria interactions.



Other interventions, such as exclusive enteral nutrition and low-FODMAP diets, also show benefits in gut diseases.



<h2 class="wp-block-heading" id="h-probiotics-prebiotics-and-phages">Probiotics, prebiotics, and phages</h2>



Probiotics introduce beneficial bacteria, while prebiotics feed them. Combining them, known as symbiotics, shows promise for restoring and maintaining gut health.



Recent research suggests that adding phages can enhance these effects. Phage-based products, such as PreforPro, have already shown benefits in clinical trials.



These products can reduce populations of harmful bacteria and improve probiotic performance, thereby creating a more stable gut environment.



<h2 class="wp-block-heading" id="h-using-gut-viruses-to-detect-diseases-early">Using gut viruses to detect diseases early</h2>



The gut virome is now being studied as a diagnostic tool. Viral patterns are more stable than bacterial ones, making them reliable biomarkers.



Distinct virome signatures can predict IBD and colorectal cancer. Machine learning models already use virome data to detect these diseases early.



Virome profiling may also track treatment responses, such as FMT success in IBD and CDI.



<h2 class="wp-block-heading" id="h-challenges-and-future-prospects">Challenges and future prospects</h2>



Despite the excitement over potential new treatments, many hurdles remain. Current methods struggle to capture the full virome due to technical limits.



Many phages are still unculturable, and their roles remain unclear. Researchers are working to improve viral databases and develop targeted therapies. Once these gaps close, virome-based therapies could change how we treat gut diseases.



The study is published in the journal <a href="https://academic.oup.com/pcm/article/8/2/pbaf010/8152264" target="_blank" rel="noreferrer noopener">Precision Clinical Medicine</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.



-----

Move over microbiome, it's time for the human gut's 'virome' to shine

For years, bacteria dominated gut health research. Now, the gut...

Phyllium,Is,The,Largest,And,Most,Widespread,Genus,Of,Leaf

In the wild, survival often depends on looks. Some insects evolve disguises that trick their predators into keeping a safe distance. One of the most fascinating examples of this is <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/batesian-mimicry" target="_blank" rel="noreferrer noopener">Batesian mimicry</a>, where harmless species mimic dangerous ones.



Predators that are wary of painful stings, or toxic bites, learn to avoid the warning patterns on the bodies of these potential prey species. 



But some other species evolve to copy these signals, despite being completely harmless themselves. This strange dance of deception shapes the appearance of many species worldwide.



Recently, researchers at the <a href="https://www.nottingham.ac.uk" target="_blank" rel="noreferrer noopener">University of Nottingham</a> pushed this idea further. They explored how advanced 3D printing technologies can unravel mysteries surrounding mimicry. Their results revealed surprising insights about evolution, <a href="https://www.earth.com/news/insects-are-still-disappearing-and-there-are-hundreds-of-reasons-why/">predators</a>, and survival strategies.



This study not only shines a light on insect mimicry but also offers a deeper look at the forces that mold nature’s endless forms.



<h2 class="wp-block-heading" id="h-how-predators-judge-insect-disguises">How predators judge insect disguises</h2>



The Nottingham team, led by Dr. Tom Reader and Dr. Christopher Taylor, decided to take an experimental leap. They created life-size, 3D-printed models of insects to study how predators respond to different levels of mimicry.



By controlling every aspect of these models - such as shape, color, size, and patterns - they crafted accurate representations of real <a href="https://www.earth.com/news/rising-heat-shrinking-habitats-insects-face-hidden-threats/">species</a>. These included wasps that are known for their stings, and hoverflies that are famous mimics of wasps.



This approach allowed the scientists to explore a central question: Why do some mimics look almost identical to their models, while others resemble them only vaguely?



With 3D printing, they could manipulate every trait precisely and test how predators react to slight variations. This marked a significant step beyond previous studies that relied on natural specimens alone.



“In our study, we are asking a question about how evolution works and what determines where evolution reaches at a particular point in time," Dr. Reader said.



"Our experiments looked at the competing influences which might ultimately shape what organisms look like. Insects and mimicry offer a powerful and accessible way to investigate questions that are relevant across the entire tree of life,” he explained.



<h2 class="wp-block-heading" id="h-color-and-shape-matter">Color and shape matter</h2>



The team employed cutting-edge imaging tools to scan real wasps and <a href="https://www.earth.com/news/hoverflies-navigate-by-aligning-their-bodies-with-the-sun/">hoverflies</a>. Then, using advanced morphing software, they modified these images to create insects with varying degrees of accuracy in terms of mimicry.



These experiments allowed the researchers to demonstrate the potential for using modern 3D imaging, along with computer morphing, to design insect models that displayed many different combinations of colors and patterns, shapes and sizes.



“The models enabled us to ask ‘what-if’ questions about these insects. What if they were better mimics because their color was more wasp-like?" said Dr. Taylor.



"It allowed us to play around with the insect’s appearance in a way you can’t with real specimens," he said. "Which meant we could ask a much broader range of questions about what it is that makes a good or bad mimic.”



This experimental flexibility opened new doors for exploring mimicry. The researchers could fine-tune every trait independently and combine them in unexpected ways.



Their key aim was to understand how much precision a mimic needs in order to avoid being eaten. They also wanted to see why poor mimics still manage to survive in nature.



<h2 class="wp-block-heading" id="h-birds-demand-better-insect-disguises">Birds demand better insect disguises</h2>



In their experiments, the scientists presented their models to real predators in controlled settings. Their main subjects were wild birds, particularly great tits, which rely heavily on sight to identify prey.



The results showed that birds responded strongly to variations in mimicry. They focused mainly on color and size, ignoring finer pattern details.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/07/insect-imitation_3d-printed-wasps_credit-UNottingham_1m.jpg"><img src="https://www.earth.com/wp-content/uploads/2025/07/insect-imitation_3d-printed-wasps_credit-UNottingham_1s.webp" alt="3D printed models of a common wasp. The model in front is life-sized. Credit: Dr. Tom Reader (University of Nottingham)" class="wp-image-1976458"/></a><figcaption class="wp-element-caption">3D printed models of a common wasp. The model in front is life-sized. Click image to enlarge. Credit: Dr. Tom Reader (University of Nottingham)</figcaption></figure>



The birds were quick learners. They soon began to avoid models that looked more like wasps, even if those models were still rewarding to eat.



Interestingly, the team discovered that intermediate mimics, those blending traits of two different wasp models, gained no extra protection. Birds seemed to prefer clear signals over mixed ones, demanding accurate mimicry.



<h2 class="wp-block-heading" id="h-sloppy-mimics-still-survive">Sloppy mimics still survive</h2>



While birds proved strict judges, invertebrate predators reacted differently. The team tested crab spiders, jumping spiders, and mantises alongside birds to compare predator responses.



Invertebrates showed less concern about precise mimicry. They tolerated models with poor resemblance and attacked more broadly.



This revealed an important insight: <a href="https://www.earth.com/news/ocean-noise-can-be-fatal-to-marine-invertebrates/">invertebrates</a> impose weaker pressure on mimics to evolve perfect disguises. Some insects can survive despite their sloppy mimicry if their main threats come from these predators.



This creates a fascinating evolutionary tension. Birds push for more accurate mimics, but invertebrates allow greater variation to persist.



<h2 class="wp-block-heading" id="h-how-evolution-shapes-insect-disguises">How evolution shapes insect disguises</h2>



A major breakthrough in this study was the creation of an adaptive <a href="https://www.earth.com/news/modern-farming-is-causing-many-insect-species-to-collapse/">landscape</a> for mimicry. By using their 3D printed models, the team could systematically map how changes in traits affected predator decisions.



They designed smooth transitions between models, allowing them to visualize shifts in predator responses as traits varied. The experiments showed that the landscape was steep for color and size, traits that birds select strongly for, but flatter for other features like pattern.



This landscape explained why some mimics evolve to look highly accurate, while others remain imperfect. It all depends on the types of predators in their environment.



In bird-heavy areas, precise mimicry becomes essential. In areas dominated by invertebrates, imperfect mimics can survive without major risks.



<h2 class="wp-block-heading" id="h-simulating-future-disguises">Simulating future disguises</h2>



3D modeling and visualization tools allow researchers to create life-size, full-color models of potential past or future hoverflies and then test them with real predators like birds and <a href="https://www.earth.com/news/spiders-adapt-their-webs-to-filter-out-human-made-noise/">spiders</a> to see how they respond to those traits.



“As an evolutionary biologist, you are constantly trying to understand something that happened in the past, and without a time machine you can’t know how a hoverfly ended up like it did, " Dr. Reader said.



This study not only revealed the subtle pressures shaping insect disguises today but also hinted at how those forces may have operated throughout history.



By bridging technology and biology, the team has crafted a remarkable tool for studying evolution. Their work helps explain how nature fine-tunes survival strategies and keeps evolving in unexpected ways.



Their experiments brought new clarity to questions that have puzzled scientists for decades, showing how insect mimicry remains one of nature’s most astonishing tricks.



The study is published in the journal <a href="https://www.nature.com/articles/s41586-025-09216-3" 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.



-----

Mimicry among insects: 3D models reveal how nature's disguises trick predators

In the wild, survival often depends on looks. Some insects...

What is Cadmium?

News coming your way