Pharella olivacea

<p>Researchers at the <a href="https://www.york.ac.uk/" target="_blank" rel="noreferrer noopener">University of York</a> have made a breakthrough discovery in the field of evolutionary biology by mapping the family tree of crocodiles, including their extinct relatives known as Pseudosuchia. </p>



<p>The comprehensive study offers new insights into the evolutionary history of crocodiles, particularly focusing on the question of why today's world has such a limited variety of croc species compared to their avian relatives, <a href="https://www.earth.com/news/do-birds-dream-of-flying-scientists-say-they-now-know-the-answer/">birds</a>.</p>



<h2 class="wp-block-heading" id="h-how-the-research-was-conducted-nbsp">How the research was conducted&nbsp;</h2>



<p>The team, led by Dr. Katie Davis from the Department of Biology, meticulously combined data from the fossil record with their detailed mapping of the crocodile lineage.&nbsp;</p>



<p>This approach revealed significant insights into the factors influencing the survival and extinction of these species over millions of years.&nbsp;</p>



<h2 class="wp-block-heading" id="h-key-insights">Key insights</h2>



<p>A key finding of the research is the crucial role that ecology played in the survival of different crocodile species. The team discovered that changes in global temperatures affected sea-dwelling and land-based crocodilians differently than freshwater species.&nbsp;</p>



<p>Interestingly, while the diversity of sea-dwelling and land-based crocodiles increased with rising temperatures, they were more susceptible to extinction due to increased competition for resources, possibly with marine predators like sharks or dinosaurs.&nbsp;</p>



<p>Bt contrast, freshwater species were less impacted by temperature changes but faced greater extinction risks due to rising sea levels.</p>



<h2 class="wp-block-heading" id="h-conservation-efforts-nbsp">Conservation efforts&nbsp;</h2>



<p>This study is not just a deep dive into the past, but holds significant implications for contemporary conservation efforts.&nbsp;</p>



<p>With several crocodile species today classified as critically endangered or vulnerable, understanding the historical factors that influenced their survival becomes crucial in a world grappling with climate change.&nbsp;</p>



<h2 class="wp-block-heading" id="h-valuable-fossil-record">Valuable fossil record</h2>



<p>“The fossil record is a rich source of valuable information allowing us to look back through time at how and why species originate, and crucially, what drives their extinction," said Dr. Davis.&nbsp;</p>



<p>"By examining this record and mapping it against the crocodile family tree, our research reveals how important it is to think about ecology when we're trying to predict how species might respond to today's climate change."</p>



<p>“With a million plant and animal species perilously close to extinction, understanding the key factors behind why species disappear has never been more important."&nbsp;&nbsp;</p>



<p>"In the case of crocodiles, many species reside in low-lying areas, meaning that rising sea levels associated with global warming may irreversibly alter the habitats on which they depend.”</p>



<h2 class="wp-block-heading" id="h-study-significance-nbsp">Study significance&nbsp;</h2>



<p>The research highlights the interconnectedness of abiotic factors like climate and biotic interactions such as competition in shaping the evolutionary journey of species.&nbsp;</p>



<p>By constructing a large phylogeny for all crocodiles and their extinct relatives, the researchers could analyze speciation and extinction patterns in relation to historical climate changes.&nbsp;</p>



<p>The team employed a type of mathematics called the Information Theory to estimate the impact of these environmental and interactive factors on species emergence and extinction rates.</p>



<p>“Crocodiles and their extinct relatives offer unique insights into climate change and its impact on biodiversity in the past, present and future," said Dr. Davis. "Our findings advance our understanding of what factors have shaped, and continue to shape, life on Earth.”</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1038/s41559-023-02244-0" target="_blank" rel="noreferrer noopener"><em>Nature Ecology &amp; Evolution</em></a><em>.</em></p>



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Climate and ecology shaped 250 million years of crocodile evolution

Researchers at the University of York have made a breakthrough...

<p>The results of a study led by <a href="https://www.ucl.ac.uk/" target="_blank" rel="noreferrer noopener">University College London</a> (UCL) are challenging long-standing beliefs about the development of human brains in <a href="https://www.earth.com/news/babies-are-born-with-the-ability-to-recognize-the-beat-in-music/">newborns</a> compared to other primates.&nbsp;</p>



<p>According to the research, the idea that human newborns have underdeveloped brains is a misconception. The experts found that the brains of newborns are at a development level typical for primates.</p>



<h2 class="wp-block-heading" id="h-false-impression">False impression</h2>



<p>Human brains grow so much larger and more complex than other species after birth. This creates a false impression that newborns are underdeveloped, or “altricial.”</p>



<p>“This new work changes the overall understanding around the evolution of human brain development," said study lead author Dr. Aida Gomez-Robles.</p>



<p>"Humans seem so much more helpless when they’re young compared to other primates not because their brains are comparatively underdeveloped but because they still have much further to go.”</p>



<h2 class="wp-block-heading" id="h-human-brain-development-nbsp">Human brain development&nbsp;</h2>



<p>The research modifies the conventional view that human brains are less developed at birth due to evolutionary compromises, such as the need for babies’ heads to fit through the birth canal.</p>



<p>Traditionally, scientists have assessed brain development across species by comparing brain sizes at birth with adult brain sizes. This suggested that humans are born with a smaller percentage of their adult brain size compared to other primates, leading to the belief in their relative underdevelopment.&nbsp;</p>



<p>However, the UCL study indicates that other measures of human brain development align closely with other primates like chimpanzees, bonobos, gorillas, and orangutans.</p>



<h2 class="wp-block-heading" id="h-study-implications-nbsp">Study implications&nbsp;</h2>



<p>The study also addresses the implications of these findings for the concept of brain plasticity in human evolution. It has been suggested that the perceived underdevelopment at birth results in greater brain malleability and sensitivity to environmental stimuli during early life, contributing to human intelligence.&nbsp;</p>



<p>The researchers clarify that while human brains do take longer to reach full capacity, this does not stem from significant underdevelopment at birth. Thus, while brain plasticity remains critical in human evolution, it is unlikely to be a result of being less developed at birth than other primates.</p>



<h2 class="wp-block-heading" id="h-how-the-research-was-conducted">How the research was conducted</h2>



<p>To conduct this analysis, the team examined the brain development of 140 different mammal species, including modern primates, rodents, carnivores, and the fossils of early humans and ancestral hominins.&nbsp;</p>



<p>The researchers compared fetal gestation lengths, the relative size of newborn brains and bodies to adult sizes, and overall brain size at birth and adulthood across these species.&nbsp;</p>



<p>The findings revealed that while there are considerable variations in brain development at birth among different mammal species, primates, including humans, show a consistent pattern of development.</p>



<p>This research, supported by the <a href="https://www.nsf.gov/" target="_blank" rel="noreferrer noopener">National Science Foundation</a> and the National Institutes of Health in the US, marks a significant shift in the understanding of human brain development and its evolutionary trajectory, challenging long-held assumptions in the field of anthropology and neurology.</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1038/s41559-023-02253-z" target="_blank" rel="noreferrer noopener"><em>Nature Ecology &amp; Evolution</em></a>.</p>



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Human brain development aligns closely with other primates

The results of a study led by University College London...

<p>A staggering event on October 4-5 in Chicago led to the demise of nearly 1,000 <a href="https://www.earth.com/news/window-collisions-are-a-leading-cause-of-bird-mortality/">birds</a>, as they crashed into a brightly lit glass structure. While such extensive bird fatalities are uncommon, artificial light remains a significant and escalating hazard to migratory birds.</p>



<p>In a comprehensive study published in <a href="http://dx.doi.org/10.1038/s41467-023-43046-z" target="_blank" rel="noreferrer noopener"><em>Nature Communications</em></a>, researchers employed weather radar data to chart bird stopover densities across the U.S. The study revealed that artificial light is a prime factor influencing where birds land during migration.&nbsp;</p>



<h2 class="wp-block-heading" id="h-birds-face-multiple-challenges-nbsp">Birds face multiple challenges&nbsp;</h2>



<p>Kyle Horton, an assistant professor at <a href="https://www.colostate.edu/" target="_blank" rel="noreferrer noopener">Colorado State University</a>’s Department of Fish, Wildlife and Conservation Biology and the study’s lead author, explained that city lights can entice birds into hazardous urban environments.</p>



<p>The challenges for migrating birds in urban areas are manifold, including dangerous building collisions, habitat loss, limited food availability, and threats from humans and predators like cats. Urban parks offer some respite, but they come with their own set of challenges, such as competition for scarce resources.</p>



<h2 class="wp-block-heading" id="h-migration-stopover-hotspots">Migration stopover hotspots</h2>



<p>Migration is fraught with peril for birds, involving extensive travel that can deplete up to half of their body mass. “These stopover locations are the fueling stations,” Horton said. “If they don’t have a good spot to rebuild energy supplies, migration can’t happen."</p>



<p>This study marks the first time migration stopover hotspots across the contiguous United States have been mapped on such a large scale. Understanding these patterns can aid in developing conservation strategies.</p>



<p>“Cities pose multiple risks to migrating birds,” explained co-author and <a href="https://msu.edu/">Michigan State University</a> Professor Geoff Henebry. “They also offer resources for the tired birds to rest and refuel."&nbsp;</p>



<p>"Our study is notable in that it combines big data – and a lot of processing – from the weather surveillance radar network with big data from multiple spaceborne sensors to address key questions regarding the influence of urban areas on bird migration.”</p>



<h2 class="wp-block-heading" id="h-helping-birds-survive-artificial-light">Helping birds survive artificial light</h2>



<p>However, the attraction of birds to cities raises a conservation dilemma: should urban areas be preserved as vital stopover sites, or should efforts be concentrated on reducing urban lighting? Horton is collaborating with various organizations to tackle both issues, but the multifaceted nature of urban lighting presents complexities.</p>



<p>Light pollution not only affects birds but also disrupts human circadian rhythms, contributing to several health issues. “We don’t often think about light as a pollutant, but it checks all the boxes of what pollution is,” Horton said.</p>



<h2 class="wp-block-heading" id="h-migration-forecasts-nbsp">Migration forecasts&nbsp;</h2>



<p>Initiatives like <a href="https://birdcast.info/">BirdCast</a> offer migration forecasts and real-time maps, enabling individuals and cities to minimize artificial light on critical migration nights. Simple measures, such as retrofitting windows with decals and adjusting light brightness and color, can significantly reduce bird collisions.</p>



<p>The tragic incident at Chicago’s McCormick Place Convention Center is a stark reminder of the dangers of light pollution. Public awareness and simple actions, like turning off unnecessary lights, can have an immediate and beneficial impact on bird safety.&nbsp;</p>



<p>“If we turned off all lights tonight, there would be no birds colliding because of lights tonight,” Horton concluded.</p>



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Artificial light is luring birds to their deaths around the world by the millions

A staggering event on October 4-5 in Chicago led to...

Polar,Bear,On,The,Ice,Sniffing,In,The,Air

<p>Polar bears, the majestic icons of the Arctic, are elusive and vulnerable, making their conservation a challenging task. However, a breakthrough in DNA analysis using skin cells shed in their footprints offers new hope for monitoring these endangered species.</p>



<p>This innovative method, developed by a team of international scientists, promises a less invasive and more efficient way to gather essential data on <a href="https://www.earth.com/news/study-confirms-direct-link-between-polar-bear-survival-and-harmful-emissions/" target="_blank" rel="noreferrer noopener">polar bear populations</a>.</p>



<h2 class="wp-block-heading" id="h-monitoring-polar-bears-with-footprint-dna">Monitoring polar bears with footprint DNA</h2>



<p>Dr. Melanie Lancaster of the World Wide Fund for Nature <a href="https://www.arcticwwf.org/" target="_blank" rel="noreferrer noopener">Global Arctic Programme</a> is the senior author of the study. “It is particularly challenging, expensive, and time-consuming to find polar bears in the Arctic, let alone count them and understand how they are coping with climate change,” said Lancaster.</p>



<p>The difficulties in locating and counting these bears, combined with the need to understand their response to climate change, has left a gap in critical data regarding their population size and connectivity.</p>



<p>Inspired by forensic techniques suited for tiny, degraded DNA samples, the scientists developed a method that avoids the physical capture of bears. This method avoids an often stressful and dangerous situation for both the animals and humans. Elisabeth Kruger of the <a href="https://www.worldwildlife.org/" target="_blank" rel="noreferrer noopener">World Wildlife Fund</a>, another author of the article, highlights the significance of this method. </p>



<p>“Many Inuit express concern about invasive research methods,” said Kruger. “People are concerned about the welfare of the individual <a href="https://www.earth.com/news/scientists-unravel-the-secrets-of-polar-bear-fur/" target="_blank" rel="noreferrer noopener">polar bear</a> and the health and safety of people who may harvest the bear later. This is one of the reasons we are so excited about new methods like this - the person collecting the sample never needs to even see or be seen by the polar bear.”</p>



<h2 class="wp-block-heading" id="h-edna-from-animal-tracks">eDNA from animal tracks</h2>



<p>A unique aspect of this research involves the use of <a href="https://www.earth.com/news/environmental-dna-can-help-monitor-pollinators/" target="_blank" rel="noreferrer noopener">environmental DNA</a> (eDNA) found in the snow track footprints of polar bears. Dr. Micaela Hellström of <a href="https://www.mixresearch.se/" target="_blank" rel="noreferrer noopener">MIX Research Sweden AB</a>, the lead author of the study, explains that the tracks contain fresh cells with intact DNA.</p>



<p>“The tracks usually contain fresh cells, and the DNA is intact because of the cold ‘storage’ temperature. DNA that has passed the gut is much more degraded and therefore more challenging to work on,” said Hellström.</p>



<p>The team collected snow from individual tracks of Alaskan <a href="https://www.earth.com/news/radar-imaging-will-help-protect-polar-bears-from-human-disturbances/" target="_blank" rel="noreferrer noopener">polar bears</a> and Swedish Eurasian lynxes, both in the wild and captivity, as well as from a captive snow leopard. Confirming the accuracy of the genotypes derived from this snow track DNA, additional materials like hair, saliva, and mucus were also sampled. </p>



<h2 class="wp-block-heading" id="h-footprint-dna-analysis-results">Footprint DNA analysis results</h2>



<p>The researchers sampled 24 wild polar bear tracks and 44 wild <a href="https://www.earth.com/news/lynx-habitat-selection-is-heavily-influenced-by-human-disturbance/" target="_blank" rel="noreferrer noopener">lynx</a> tracks. They melted and filtered the snow from these tracks to collect environmental DNA, which they then analyzed using microsatellite analysis. </p>



<p>Despite the low concentrations of DNA in the tracks collected from the wild, they successfully retrieved nuclear DNA from 87.5% of the wild <a href="https://www.earth.com/news/how-do-polar-bears-get-traction-on-ice/" target="_blank" rel="noreferrer noopener">polar bear</a> tracks and 59.1% of the wild <a href="https://www.earth.com/news/lynx-population-in-france-is-on-the-brink-of-extinction/" target="_blank" rel="noreferrer noopener">lynx</a> tracks. They managed to genotype 13 of the wild polar bear samples, identifying 12 different individuals.</p>



<p>When focusing on the lynx tracks sampled by trained personnel, the genotyping success rate improved significantly. The scientists retrieved nuclear DNA from 76% of the samples collected by these trained individuals, and they successfully genotyped 24% of these samples.</p>



<p>This non-invasive sampling technique, despite a lower success rate compared to traditional methods, offers considerable advantages. It not only reduces the stress and danger associated with physical capture but also allows for larger sample sizes due to its ease of collection. </p>



<h2 class="wp-block-heading" id="h-implications-for-conservation">Implications for conservation</h2>



<p>The potential of this technique to inform conservation strategies, understand animal populations and behaviors, and manage human-animal conflicts is immense.</p>



<p>Dr. Lancaster expresses hope that this method will be adopted widely by the polar bear research community, involving hunters, volunteers, and Indigenous communities. She says, “We hope this method will be taken up by the <a href="https://www.earth.com/news/polar-bears-threatened-by-toxic-chemicals-in-melting-sea-ice/" target="_blank" rel="noreferrer noopener">polar bear</a> research community, with the involvement of hunters, volunteers, and Indigenous communities, as a new way to collect information on polar bears.”</p>



<p>The team also anticipates the expansion of this technique to other animals living in snowy environments, having already demonstrated its effectiveness with lynx and snow leopards.</p>



<p>In summary, this groundbreaking research in DNA analysis using <a href="https://www.earth.com/news/scientists-vacuumed-animal-dna-from-a-forest-and-the-results-are-amazing/" target="_blank" rel="noreferrer noopener">environmental DNA</a> from snow tracks and footprints opens a new chapter in wildlife conservation. It promises a more humane, efficient, and inclusive approach to studying and protecting one of the Arctic's most iconic inhabitants, the polar bear, and potentially other species in similar environments.</p>



<p>The full study was published in the journal <em><a href="https://www.frontiersin.org/articles/10.3389/fcosc.2023.1250996/full" target="_blank" rel="noreferrer noopener">Frontiers in Conservation Science</a></em>.</p>



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Footprint DNA helps scientists monitor elusive animals like polar bears

Polar bears, the majestic icons of the Arctic, are elusive...

Chinstrap,Penguin,,Antarctica,,January,2019

<p>In a new study, researchers have discovered that nesting chinstrap penguins in the wild manage to accumulate over 11 hours of sleep daily, not through extended rest periods, but via thousands of brief microsleeps. </p>



<p>This fascinating sleep behavior underscores the adaptability and resilience of these birds in maintaining continuous vigilance over their nests.</p>



<h2 class="wp-block-heading" id="h-importance-of-sleep-to-animals">Importance of sleep to animals</h2>



<p>Sleep, a state typically marked by immobility and a decreased sensory response to the environment, is a common trait across various species. Sleeping, while restorative, can make animals vulnerable to predators. </p>



<p>In humans, lack of adequate sleep often leads to microsleeps -- brief, seconds-long lapses in wakefulness characterized by eye closure and sleep-like brain activity. These involuntary pauses can be hazardous, especially in activities like driving. </p>



<p>However, the true restorative value of such microsleeps in comparison to longer sleep periods remains a subject of scientific inquiry.</p>



<h2 class="wp-block-heading" id="h-studying-how-chinstrap-penguins-sleep">Studying how chinstrap penguins sleep</h2>



<p>Paul-Antoine Libourel and his team spearheaded a comprehensive study on a colony of chinstrap penguins (<em>Pygoscelis antarcticus</em>) in Antarctica. </p>



<p>These penguins, while nesting, face the constant need to protect their nests from predators and other intruding penguins, especially when their partners are away. This situation demands that one parent remains vigilant, making extended sleep periods impractical and potentially dangerous.</p>



<p>The team employed remote electroencephalogram (EEG) monitoring, along with other noninvasive sensors, to record the sleep patterns of these freely roaming and nesting birds. Continuous video surveillance and direct observations complemented this study.</p>



<p>Contrary to typical sleep patterns observed in many animals, chinstrap penguins did not engage in long sleep sessions. Instead, they were found to frequently fall into microsleeps, each lasting about 4 seconds on average. Remarkably, they accumulated over 11 hours of sleep per day through more than 10,000 of these microsleep episodes.</p>



<h2 class="wp-block-heading" id="h-implications-and-perspectives">Implications and perspectives</h2>



<p>The study's findings suggest that these brief sleep bouts, or microsleeps, can collectively fulfill some of the restorative functions traditionally associated with longer sleep periods. This adaptation appears to be a successful strategy for species like chinstrap penguins that require constant vigilance.</p>



<p>Christian Harding and Vladyslav Vyazovskiy, in a related perspective, highlighted the significance of these findings. They noted that the chinstrap penguins' microsleeps might represent one of the most extreme examples of how the benefits of sleep can accumulate incrementally. This observation opens new avenues for understanding sleep patterns and their variations across different species.</p>



<p>The research conducted by Libourel and colleagues sheds light on the remarkable adaptability of chinstrap penguins in fulfilling their sleep needs through microsleeps. This study adds to our understanding of sleep in wild animals. It also raises intriguing questions about the flexibility and functionality of sleep across different species. </p>



<p>The chinstrap penguins' unique sleep pattern is a testament to the diverse strategies employed by animals to balance the demands of survival and rest.</p>



<h2 class="wp-block-heading" id="h-more-about-chinstrap-penguins">More about chinstrap penguins</h2>



<p>As touched on above, chinstrap penguins are easily recognizable by their distinctive facial markings. They are a fascinating species of penguins that reside primarily in the islands and shores of the Southern Pacific and the Antarctic Ocean. Let's dive deeper into their life, habitat, behavior, and the challenges they face.</p>



<h3 class="wp-block-heading" id="h-physical-characteristics">Physical characteristics</h3>



<p>Chinstrap penguins stand out with their thin black band under the head, resembling a helmet strap, which gives them their name. They are medium-sized penguins, typically weighing between 3 to 6 kilograms. Their bodies are adapted to the aquatic environment. Chinstraps have streamlined shapes, flippers for swimming, and a layer of insulating feathers to protect against the cold.</p>



<h3 class="wp-block-heading" id="h-chinstrap-penguins-habitat">Chinstrap penguins habitat</h3>



<p>Primarily found on the Antarctic Peninsula and surrounding islands, chinstrap penguins thrive in large colonies on ice-free coastal areas. Their choice of habitat is largely influenced by the availability of their primary food source, the krill, which is abundant in these cold waters.</p>



<h3 class="wp-block-heading" id="h-diet-and-feeding-habits">Diet and feeding habits</h3>



<p>Krill constitutes the major part of a chinstrap penguin's diet, although they also consume fish and squid. They are excellent swimmers and can dive to depths of up to 70 meters in pursuit of prey. Their feeding expeditions can last several hours, during which they skillfully navigate through the water.</p>



<h3 class="wp-block-heading" id="h-breeding-and-lifecycle">Breeding and lifecycle</h3>



<p>Chinstrap penguins are monogamous and often return to the same mate each breeding season. The breeding season starts in November when they gather in vast colonies to nest. Females typically lay two eggs, and both parents share the responsibility of incubating the eggs and feeding the chicks. The chicks fledge after about two months and are ready to go to sea.</p>



<h3 class="wp-block-heading" id="h-chinstrap-penguins-social-behavior">Chinstrap penguins social behavior</h3>



<p>These penguins are highly social birds. Their colonies, sometimes consisting of hundreds of thousands of individuals, are a hub of activity. The colonies help provide protection against predators and are also crucial for the birds' social interactions. This includes finding mates and caring for their young.</p>



<h3 class="wp-block-heading" id="h-threats-and-conservation">Threats and conservation</h3>



<p>Chinstrap penguins face several threats. Most notably, climate change, which affects their food supply, and human activities such as fishing and pollution. While they are not currently endangered, their populations are under observation for potential decline due to these environmental pressures.</p>



<p>In summary, chinstrap penguins are a remarkable species, adept at surviving and thriving in some of the harshest conditions on Earth. Their unique physical features, social behaviors, and breeding habits make them an important subject of study for understanding the dynamics of marine life in the Antarctic ecosystem. </p>



<p>As they navigate the challenges posed by a changing environment, the continued study and conservation of chinstrap penguins remain crucial for ensuring their survival.</p>



<p>The full study was published in the journal <em><a href="https://www.science.org/doi/10.1126/science.adh0771" target="_blank" rel="noreferrer noopener">Science</a></em>.</p>



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Chinstrap penguins take over 10,000 micro-sleeps per day

In a new study, researchers have discovered that nesting chinstrap...

<p>A recent study from Japan has revealed that owning a <a href="https://www.earth.com/news/mischievous-dogs-experts-reveal-the-top-ten-naughtiest-breeds/">dog</a> can significantly reduce the risk of developing dementia in old age. The experts found that dog owners over the age of 65 were 40 percent less likely to develop dementia.</p>



<p>The study marks the first scientific establishment of a clear link between dog ownership and a lowered risk of dementia.</p>



<h2 class="wp-block-heading" id="h-studying-dog-owners">Studying dog owners</h2>



<p>The research wad focused on nearly 12,000 residents in Tokyo aged 65 and older. It was conducted over four years by the <a href="https://www.tmig.or.jp/" target="_blank" rel="noreferrer noopener">Tokyo Metropolitan Institute for Geriatrics and Gerontology</a>.&nbsp;</p>



<p>The experts compared the mental health of older adults who were current dog owners, previous owners, and those who never owned a dog.</p>



<p>The researchers meticulously accounted for various factors including gender, marital status, education, income, health history, and exercise habits, regardless of pet ownership. The average age of the participants was 74.2 years, with 51.5% being female.&nbsp;</p>



<h2 class="wp-block-heading" id="h-regular-exercise-and-social-interaction-nbsp">Regular exercise and social interaction&nbsp;</h2>



<p>Dr Yu Taniguchi, the lead author of the study, noted that individuals who owned a dog had therefore exercised, making new connections with people as they walked their pets.</p>



<p>“Having a dog enabled owners to habitually take exercise and avoid social isolation and these were the two key factors in people having a much lower risk of developing dementia,” explained Dr. Taniguchi.</p>



<p>Interestingly, the researchers found that the protective effects against dementia were still present in dog owners who did not regularly exercise or engage socially, though to a lesser extent than those who did.&nbsp;</p>



<p>“Having a dog effectively requires people to get into the habit of physical activity and that makes it much more likely that they will then have interactions and socialize with other people,” said Dr. Taniguchi.</p>



<h2 class="wp-block-heading" id="h-cats-and-dementia-nbsp">Cats and dementia&nbsp;</h2>



<p>The researchers also investigated the relationship between owning cats and dementia. They determined that cat ownership was not effective for preventing dementia</p>



<p>This is due to the fact that owners do not walk their cats and they do not bring people together socially in the way that dogs do, said Dr. Taniguchi, who has a Jack Russell terrier.</p>



<p>He added that he was not surprised by the group’s findings, as earlier research had identified the potential health benefits of pets.</p>



<h2 class="wp-block-heading" id="h-frailty-and-disability-nbsp">Frailty and disability&nbsp;</h2>



<p>Prior research has already hinted at the health benefits of dog ownership, including reduced frailty in old age and delayed onset of disabilities and death</p>



<p>"Although some previous study reported no-significant association of pet ownership with mortality, systematic review and meta-analysis concluded that dog ownership is associated with lower risk of death over the long term," wrote Dr. Taniguchi and his co-authors.</p>



<p>"Our previous study revealed that older adults who had owned a dog and/or cat had lower risk of incident frailty, with dog owners at baseline showing 0.81 times the likelihood of developing incident frailty than never dog owners during 2-year follow-up period."</p>



<h2 class="wp-block-heading" id="h-improved-well-being-of-dog-owners">Improved well-being of dog owners</h2>



<p>During the coronavirus pandemic, dog owners also reported better well-being than those without pets, likely due to increased exercise and social opportunities.</p>



<p>"Dog care might contribute to the maintenance of physical activity, including having an exercise habit, and social participation even in the face of restrictions to interactions such as those experienced during the COVID-19 pandemic," wrote the researchers.&nbsp;</p>



<p>The study is published in the December edition of <a href="https://www.sciencedirect.com/science/article/pii/S221133552300356X" target="_blank" rel="noreferrer noopener"><em>Preventive Medicine Reports</em></a>.</p>



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Dog owners are much less likely to develop dementia

A recent study from Japan has revealed that owning a...

Brittle,Stars,Or,Ophiuroids,Are,Echinoderms,In,The,Class,Ophiuroidea

<p>In the quest to understand intelligence and learning, humans have often focused on brain size as a key factor. However, a fascinating study on brainless brittle stars challenges this notion, revealing that these creatures are capable of learning through experience, despite lacking a centralized brain.</p>



<h2 class="wp-block-heading" id="h-enigmatic-brittle-stars">Enigmatic brittle stars</h2>



<p>Brittle stars, related to <a href="https://www.earth.com/news/crown-of-thorns-starfish-are-natures-ultimate-coral-predators-and-they-are-winning/" target="_blank" rel="noreferrer noopener">starfish</a>, are fascinating marine creatures known for their secretive nature. They spend most of their time hidden under rocks or buried in sand, with their bodies consisting of five wiggly arms connected to a nerve ring near their mouth, instead of a traditional brain.</p>



<p><a href="https://jnotar.github.io/" target="_blank" rel="noreferrer noopener">Julia Notar</a>, the lead author of the study conducted at Duke University under <a href="https://scholars.duke.edu/person/sjohnsen" target="_blank" rel="noreferrer noopener">Professor Sönke Johnsen</a>, emphasizes the uniqueness of the brittle star's nervous system. "There's no processing center," explains Notar. "Each of the nerve cords can act independently, functioning more like a committee than under a central boss."</p>



<h2 class="wp-block-heading" id="h-learning-by-association">Learning by association</h2>



<p>Notar's research posits that brittle stars can learn through classical conditioning, a learning process where an organism learns to associate different stimuli.</p>



<p>One example of classical conditioning is demonstrated by Pavlov's famous experiments with dogs. When repeatedly fed at the ringing of a bell, they eventually start drooling at just the sound of the bell, even without food present.</p>



<p>Similarly, humans experience this often. When you repeatedly hear the “ding” of a smartphone alert, the sound eventually takes on a special meaning. The mere ping or buzz of someone's phone, if it matches your phone's chime, can prompt you to reflexively reach for your phone, expecting the next text, email, or Instagram post.</p>



<p>Researchers have demonstrated classical conditioning in starfish in a few previous studies. However, most <a href="https://www.earth.com/news/sea-stars-may-actually-be-walking-heads-with-no-bodies/" target="_blank" rel="noreferrer noopener">echinoderms</a>, a diverse group encompassing around <a href="https://link.springer.com/article/10.3758/s13420-021-00492-3" target="_blank" rel="noreferrer noopener">7,000 species</a> including brittle stars, brainless starfish, <a href="https://www.earth.com/news/sea-urchins-are-struggling-to-survive-because-they-cant-get-a-grip/" target="_blank" rel="noreferrer noopener">sea urchins</a>, and <a href="https://www.earth.com/news/discovery-eating-sea-cucumbers-can-prevent-diabetes/" target="_blank" rel="noreferrer noopener">sea cucumbers</a>, remain untested in this area.</p>



<h2 class="wp-block-heading" id="h-how-the-study-was-conducted">How the study was conducted</h2>



<p>To determine if brittle stars can learn, researchers placed 16 black brittle stars (<em>Ophiocoma echinata</em>) in individual water tanks and recorded their behavior with a video camera.</p>



<p>They trained half of the brittle stars by dimming the lights for 30 minutes at each feeding time. Whenever the lights went out, the researchers placed a morsel of shrimp -- a favorite of the brittle stars -- just out of reach in the tanks.</p>



<p>The researchers fed the other half the same amount of shrimp but did so under lit conditions, never coinciding with the 30-minute dark periods.</p>



<h2 class="wp-block-heading" id="h-watching-brittle-stars-learn">Watching brittle stars learn</h2>



<p>Regardless of light conditions, the animals mostly hid behind the filters in their tanks, emerging only for meals. However, only the brittle stars that received training learned to associate darkness with food.</p>



<p>In the early stages of the 10-month experiment, all the animals remained hidden when the lights dimmed. Over time, the trained brittle stars formed a connection between darkness and feeding time. They began to anticipate food and emerged from hiding whenever the lights went out, even before shrimp was introduced to the tanks.</p>



<p>These brittle stars had learned to associate the dimming lights with the likelihood of food. They responded without needing to smell or taste the shrimp. The mere dimming of the lights was sufficient to prompt them to emerge for dinner.</p>



<p>Even after a 13-day break without training, which involved repeatedly dimming the lights without feeding, the brittle stars still remembered this association.</p>



<h2 class="wp-block-heading" id="h-implications-and-future-research">Implications and future research</h2>



<p>Notar finds these <a href="https://rdcu.be/drHJO" target="_blank" rel="noreferrer noopener">results</a> exciting, as they demonstrate classical conditioning in a group of animals previously not known for such learning capabilities. </p>



<p>“Knowing that brittle stars can learn means they’re not just robotic scavengers like little Roombas cleaning up the ocean floor,” Notar said. “They're potentially able to expect and avoid predators or anticipate food because they’re learning about their environment.”</p>



<p>The study opens doors to further explore how creatures with non-standard nervous systems learn and remember. Notar plans to delve deeper into the mechanisms behind the brittle stars' learning abilities, aiming to answer the intriguing question: "How do they do it?"</p>



<p>This research fundamentally challenges our understanding of learning and intelligence in the animal kingdom. It suggests that brain size or structure may not be the sole determinants of an organism's ability to learn and adapt to its environment, paving the way for a broader and more inclusive study of intelligence in nature.</p>



<h2 class="wp-block-heading" id="h-more-about-brittle-stars">More about brittle stars</h2>



<p>As discussed above, brittle stars, fascinating and unique echinoderms, exhibit remarkable features and behaviors in marine ecosystems. Belonging to the class Ophiuroidea, these creatures are close relatives of sea stars, but they stand out due to their distinct physical characteristics and ecological roles.</p>



<h3 class="wp-block-heading" id="h-physical-description-and-diversity">Physical description and diversity</h3>



<p>Brittle stars typically possess a central disc and five slender, highly flexible arms. Unlike sea stars, their arms do not contain vital organs and are sharply demarcated from the central disc. This structure enables them to move swiftly through the water and across the seabed. They exhibit a wide array of colors and patterns, enhancing their appeal.</p>



<p>There are over 2,000 known species of brittle stars, varying greatly in size and form. Some species have smooth arms, while others have spiny or adorned ones. Their size can range from a few centimeters to nearly a meter in arm span, with the central disc usually being relatively small.</p>



<h3 class="wp-block-heading" id="h-habitat-and-distribution">Habitat and distribution</h3>



<p>Brittle stars inhabit diverse marine environments, from shallow coral reefs to the deep sea. They often hide under rocks, in coral crevices, or within seagrass beds during the day. Some species even live in symbiotic relationships with other marine organisms, such as corals.</p>



<p>Their global distribution is impressive, with species found in every ocean and at various depths, some reaching as deep as 6,000 meters. This wide distribution highlights their adaptability to different environmental conditions.</p>



<h3 class="wp-block-heading" id="h-feeding-and-nutrition">Feeding and nutrition</h3>



<p>Brittle stars are mostly scavengers and detritivores, feeding on dead organic material and small organisms. They use their flexible arms to capture food particles, which they then transport to their mouths. Some species are also known to be suspension feeders, using their arms to catch plankton and other small particles from the water column.</p>



<h3 class="wp-block-heading" id="h-reproduction-and-lifecycle">Reproduction and lifecycle</h3>



<p>Brittle stars reproduce both sexually and asexually. In sexual reproduction, they release eggs and sperm into the water, where fertilization occurs. The larvae then go through several planktonic stages before settling on the seafloor and metamorphosing into juveniles.</p>



<p>Asexual reproduction occurs through fragmentation, where a part of an arm breaks off and regenerates into a new individual. This ability also aids in their survival, as they can readily regenerate lost limbs.</p>



<h3 class="wp-block-heading" id="h-ecological-role-and-importance">Ecological role and importance</h3>



<p>Brittle stars play a crucial role in marine ecosystems. As scavengers, they aid in the decomposition process and nutrient cycling. They also serve as prey for various marine animals, including fish and crabs.</p>



<p>Their presence in various habitats makes them good indicators of environmental health. Some species are particularly sensitive to changes in water quality, making them useful in monitoring the impact of pollution and climate change on marine ecosystems.</p>



<h3 class="wp-block-heading" id="h-conservation-status">Conservation status</h3>



<p>While many brittle star species are abundant, some face threats from habitat destruction, pollution, and climate change. Their conservation is essential for maintaining the health and diversity of marine ecosystems.</p>



<p>In summary, brittle stars are not just captivating creatures but also vital components of the ocean's biodiversity. Their unique adaptations and ecological roles make them an important subject of study in marine biology and conservation efforts.</p>



<p>The full study was published in the journal <a href="https://link.springer.com/article/10.1007/s00265-023-03402-x">Behavioral </a><a href="https://link.springer.com/article/10.1007/s00265-023-03402-x" target="_blank" rel="noreferrer noopener">Ecology and Sociobiology</a>.</p>



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Brittle stars have no brain but still manage to learn

In the quest to understand intelligence and learning, humans have...

Pharella olivacea

Taxonomic tree: