Captive tigers in the U.S. now outnumber those living in the wild. According to estimates from the World Wildlife Federation, about 5,000 of these big cats reside in the U.S., mostly owned by private citizens.&nbsp;



Despite their large numbers, the health and genetic diversity of this captive population remain a mystery, posing significant questions for conservationists.&nbsp;



Could these privately owned tigers help stabilize or restore wild tiger populations, or are they too genetically compromised to be of value? Are they purebred or inbred, or do they exhibit characteristics favored in the illegal trade?



<h2 class="wp-block-heading" id="h-protecting-captive-tigers-nbsp">Protecting captive tigers&nbsp;</h2>



In a recent study, experts at <a href="https://www.stanford.edu/" target="_blank" rel="noreferrer noopener">Stanford University</a> set out to address these questions. The findings provide a new tool that both conservationists and law enforcement can use to protect captive tigers and prosecute those responsible for their mistreatment.



“We're trying to leverage genomic technology to be useful in a conservation context - there are so few tigers. We won't get a second chance if they go extinct,” said lead author Ellie Armstrong, a PhD student at Stanford.



Armstrong conducted this research as part of her doctoral studies in biology at Stanford, working with co-advisors and co-authors Elizabeth Hadly and Dmitri Petrov. 



The team initially became interested in captive tigers after studying the genetic impact of isolation on wild tiger populations.



“We were conducting a large study on wild tiger populations and leveraged these data to address the issue of captive tigers in the United States,” Armstrong said. “It was a bit unbelievable, at first, that you could have a tiger living right next door and not know it.”



<h2 class="wp-block-heading" id="h-enormous-number-of-captive-tigers-nbsp">Enormous number of captive tigers&nbsp;</h2>



Through a partnership with <a href="https://tigersinamerica.org/" target="_blank" rel="noreferrer noopener">Tigers in America</a>, Armstrong and her team discovered that an enormous number of tigers live outside accredited facilities.&nbsp;



Many of these tigers were bred for animal encounters, performed in circuses, or were trafficked as <a href="https://www.earth.com/news/exotic-pets-threaten-ecosystems/" target="_blank" rel="noreferrer noopener">exotic pets</a>. However, the team had no idea of their genetic makeup or origin.



The lack of official data on these so-called “generic” tigers (due to their unknown origin) presented a major hurdle. Although documentaries like Tiger King and The Tiger Next Door increased public awareness, accessing these animals for scientific study remained a challenge.



“There was so much hearsay associated with this captive population, and a lot of it contradicts itself,” noted Armstrong. 



“People said, 'All of the cats are really inbred,' or 'All of the cats are genetically diverse.' We had no idea what to expect and thought that genomic technology could help us answer some of these questions.”



<h2 class="wp-block-heading" id="h-genetics-of-generic-tigers-nbsp">Genetics of generic tigers&nbsp;</h2>



Through relationships with sanctuaries that had rescued generic tigers, Armstrong and her team were able to gather samples and collect data on the animals, including their rescue locations.&nbsp;



The researchers collected samples from 154 generic tigers and compared them with 100 wild tiger samples from the <a href="https://www.ncbi.nlm.nih.gov/" target="_blank" rel="noreferrer noopener">National Center for Biotechnology Information</a> (NCBI) database.



With this data, they developed a reference panel to distinguish individual tigers and identify their genetic ancestry, similar to popular genetic ancestry tests for humans.&nbsp;



“When we do 23andMe, we're not sequencing the whole genome - we're sequencing a portion of it that informs us about your health and ancestry,” Armstrong explained. “That's what we want to be able to do, but for tigers.”



The genetic database developed by the researchers has uses beyond conservation efforts. It can also assist law enforcement in prosecuting crimes related to <a href="https://www.earth.com/news/experts-are-using-forensic-science-to-fight-wildlife-trafficking/" target="_blank" rel="noreferrer noopener">wildlife trafficking</a>.



<h2 class="wp-block-heading" id="h-prosecuting-wildlife-crimes">Prosecuting wildlife crimes</h2>



The <a href="https://www.fws.gov/what-you-need-know-about-big-cat-public-safety-act" target="_blank" rel="noreferrer noopener">Big Cat Public Safety Act</a>, which went into effect on December 20, 2022, ended private ownership of <a href="https://www.earth.com/news/big-cat-brain-research/" target="_blank" rel="noreferrer noopener">big cats</a> as pets and placed restrictions on breeding, commerce, and possession of certain species, including tigers.&nbsp;



However, the <a href="https://www.fws.gov/" target="_blank" rel="noreferrer noopener">U.S. Fish and Wildlife Service</a> still has storerooms full of confiscated tiger pelts, bones, teeth, and other materials that are difficult to identify without a clear way to trace their origins.



Armstrong’s team has already received requests from the agency to apply their research in identifying confiscated materials.&nbsp;



“We'll be working with law enforcement to try to apply this in a forensic context to prosecute wildlife crimes like those seen in Tiger King, monitor the populations in the U.S., and track the illegal trade,” Armstrong said.



<h2 class="wp-block-heading" id="h-urgent-applications-of-the-research-nbsp">Urgent applications of the research&nbsp;</h2>



Using only a small portion of a genome, this reference panel can allow wildlife agencies to determine the ancestry of confiscated samples with limited DNA.&nbsp;



“That's been the most rewarding part of this research - we know that this work mattered and has immediate future applications.”



The research also sheds light on the genetic makeup of captive tigers in the U.S. Contrary to widespread rumors, these tigers do not show signs of extensive <a href="https://www.earth.com/news/inbreeding-can-actually-be-beneficial-for-some-species-in-the-long-run/" target="_blank" rel="noreferrer noopener">inbreeding</a> relative to wild tiger populations.&nbsp;



However, they also do not maintain pure subspecies ancestry, as is the case with zoo-bred tigers or wild tigers. Instead, these generic tigers are a mix of different tiger subspecies.&nbsp;



<h2 class="wp-block-heading" id="h-genetic-diversity-in-captive-tigers-nbsp">Genetic diversity in captive tigers&nbsp;</h2>



Armstrong and her team also found that the non-zoo captive tiger population does not possess more genetic diversity than their wild counterparts.



“This absence of unique genetic diversity in captive tigers means that there will be no 'genetic rescue' of wild tigers with individuals now in captivity,” said Elizabeth Hadly, one of the study’s co-authors. 



“In other words, the genetic diversity of wild tigers is all that evolution has to work with going into the future.”



Since DNA is the only way to distinguish between tiger subspecies, Armstrong believes the reference panel could be used to identify individual tigers with pure subspecies ancestry if tiger management and conservation efforts ever included releasing captive animals into the wild.



“This technology is usually a 'for fun' thing for humans, to find out more about your genetic ancestry, but we can use genomics in a very serious way to help our wildlife populations thrive in the wild and keep them from being exploited,” Armstrong concluded.



The research is published in the journal <a href="https://dx.doi.org/10.1073/pnas.2402924121" target="_blank" rel="noreferrer noopener">Proceedings of the National Academy of Sciences</a>.



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Could captive tigers help restore wild populations?

Captive tigers in the U.S. now outnumber those living in the wild. According to estimates from the World Wildlife Federation, about 5,000 of these big cats reside in the U.S., mostly owned by private citizens.&nbsp; Despite their large numbers, the health and genetic diversity of this captive population remain a mystery, posing significant questions for conservationists.&nbsp; Could these privately owned tigers help stabilize or restore wild tiger populations, or are they too genetically compromised to be of value? Are they purebred or inbred, or do they exhibit...

For a long time, scientists have used to associate <a href="https://www.earth.com/news/dogs-are-more-aware-of-actions-than-objects/">dogs</a>’ aggressiveness solely with breed. However, a paradigm shift has occurred over the past decade, due to research linking behavioral profiles to factors such as dogs’ sex, age, metabolism, and hormonal patterns.&nbsp;



Now, based on a survey of 665 dog owners detailing the physical and behavioral features of their pet dogs, a team of researchers led by the <a href="https://www5.usp.br/">University of São Paulo</a> (USP) in Brazil has investigated how morphological, environmental, and social factors modulate canine aggressiveness.



The scientists found that aggressiveness was influenced both by physical traits such as weight and skull morphology, and by social and environmental factors like the type of household the dogs lived in, the animals’ life histories, and the owner’s gender and age. These findings confirmed the hypothesis that behavior is not only learned or influenced by genetics but also the outcome of interactions with the environment.



“The results highlight something we’ve been studying for some time: behavior emerges from interaction between the animal and its context. The environment and the owner-pet relationship, as well as morphology, are all factors that influence how pets interact with us and how we interact with them,” said study senior author Briseida de Resende, a professor of Psychology at USP.



“The owner’s gender was found to be a good predictor of behavior toward strangers, in that absence of aggressiveness was 73 percent more frequent among women’s dogs,” reported lead author Flávio Ayrosa, a psychologist at the same university.&nbsp;



Moreover, the dogs’ sex and snout characteristics also appeared to influence their aggressiveness. “The likelihood of aggressive behavior toward the owner was 40 percent lower among female dogs than among males,” Ayrosa said.&nbsp;



“Snout length was even more significant: aggressiveness toward the owner was 79 percent more likely among brachycephalic [dogs with short snouts] than mesocephalic dogs [characterized by a longer snout].”&nbsp;



In addition, the researchers also discovered that the heavier the dog, the less likely it was to display aggressiveness toward its owner, with aggressive behavior decreasing by three percent per extra kilogram of body mass.



However, the scientists stressed that the owner-related findings are not necessarily cause-and-effect correlations.&nbsp;



“We found relationships, but it’s impossible to say which comes first. In the case of the factor ‘walking the dog,’ for example, it may be that people walked their dog less because the animal was aggressive, or the dog may have become aggressive because the owner didn’t take it out enough,” Ayrosa explained.&nbsp;



“Traits such as weight, height, cranial morphology, sex, and age influence the interaction between dogs and their environment. They may spend more time inside the home because of them, for example.”&nbsp;



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.applanim.2022.105766">Applied Animal Behavior Science</a>.



—



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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What factors predict aggressiveness in dogs?

For a long time, scientists have used to associate dogs’...

According to a new study led by <a href="https://www.psu.edu/">Pennsylvania State University</a>, when it comes to preserving coral reefs, what is going on above the water surface is as important as what is going on below it. By analyzing the productivity and biodiversity of the world’s symbiotic coral communities, the experts found that the maintenance of water optical quality in <a href="https://www.earth.com/news/coral-reefs-can-survive-if-given-the-chance-to-evolve/">coral reefs</a> is crucial to protect them and prevent reef degradation.



“Coral reefs are one of the most biodiverse ecosystems on Earth,” said study lead author Tomás López-Londoño, a postdoctoral fellow in Marine Sciences at Penn State. “To better understand that diversity, we looked at the role sunlight plays in the symbiotic relationship between coral and the algae that provide the oxygen for its survival. We found that underwater light intensity plays a critical role in the energy expended by the coral’s symbiotic algae to maintain its photosynthetic activity.”



Scientists have long known that sunlight is a major source of energy for basically all biochemical reactions that sustain life on our planet. Yet, sunlight’s impact on corals has often been overlooked. “What’s new here is we developed a model that provides a mechanistic explanation for the biodiversity patterns in coral,” López-Londoño explained.&nbsp;



“Central to that explanation is water clarity, meaning that preserving the underwater light climate should be a priority for coral reef conservation. It’s as vital as pollution mitigation, limiting ocean acidification, and reducing thermal stress.”



By studying coral grown in an aquarium at different depths and gradations of sunlight, the researchers developed a mathematical model describing the connection between the depth-dependent variation in photosynthetic energy to corals and gradients of species diversity. Then, they tested this model on existent data about reefs in contrasting water clarity, and discovered that much of the variation in species richness with depth is driven by changes in exposure to sunlight.



“The model is very elegant in that it takes into consideration only two things,” said study senior author Roberto Iglesias-Prieto, a professor of Biology at Penn State. “It looks at productivity, the potential that an alga has to extract energy from the sun, and the cost of living, the cost of the repair of the photosynthetic machinery. It’s a very simple notion and we found it explains the existing empirical data.”



The results suggest that highly productive underwater environments with plentiful access to sunlight may be a vital safeguard against the risk of species extinction. Moreover, the findings offer a new strategy for reef conservation: preserving the clarity of water. Local communities could be actively involved in this by reducing the sedimentation and pollution associated with human development.&nbsp;



“Unlike so much of the environmental threats that corals face, this is something that can and should be managed locally,” Iglesias-Prieto concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1038/s41598-022-25094-5">Nature Scientific Reports</a>.



—



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Access to sunlight is critical for the survival of coral reefs

According to a new study led by Pennsylvania State University,...

Dolphins are highly intelligent, social mammals that tend to form alliances that rely on <a href="https://www.earth.com/news/dogs-use-their-tails-more-for-communication-than-movement/">communication</a> between group members. Their underwater calls consist of a series of whistles, that are used to communicate with conspecifics, and clicks that are used in echolocation to identify prey items and objects in their surroundings. The animals are able to carry out cooperative tasks, such as rounding up a school of fish, that depend on successful underwater communication with others in the group.



Given the importance of underwater sound communication to dolphins and other cetaceans, it is natural to be concerned that the increasing noise levels in oceans worldwide could have significant negative impacts on the successful functioning of these animal. Ocean bed drilling, the establishment of offshore wind turbines, and increasing shipping traffic all produce underwater noise that is potentially disruptive.&nbsp;



Previous studies have found that animals from several different taxa, including mammals, birds, fish and invertebrates, respond to increased noise levels in their environments and may adopt mitigation strategies such as modifying the frequency, amplitude and duration of their calls, orientating themselves to minimize the interference from the noise source, or even moving to an entirely different area.&nbsp;



However, little is known about how successful these compensatory mechanisms are at overcoming the impacts of noise disturbance when individuals are actively working together.&nbsp;



A new experimental study by scientists from the University of Bristol, U.K., Syracuse University in New York, The Dolphin Research Center in Florida, and the Woods Hole Oceanographic Institution in Massachusetts has now tested whether the ability of two dolphins (living in human care) to solve a cooperative task is impacted by the presence of anthropogenic noise at different intensities. The results are published in the journal <a href="http://dx.doi.org/10.1016/j.cub.2022.12.063">Current Biology</a>.



The two bottlenose dolphins (Tursiop struncatus.), known as Delta and Reece, had previously been trained to carry out a cooperative task that required them to understand the role their partner must play in the task, and use the sound of whistles to coordinate their behavior with extreme precision. The task required both dolphins to swim to their own stations at opposite ends of a pool. There, they had to press their own underwater button simultaneously with the other dolphin, or within a one-second time window.&nbsp;



The two dolphins were equipped with suction-cup sound recorders to document their vocalizations as they carried out the task. During each of the 200 trials, the dolphins were released from a starting point but, for certain trials, one of the dolphins was held back for five to ten seconds while the other was released immediately to swim to its underwater button. In the delayed-release trials, the dolphins had to rely solely on vocal communication to coordinate the button press with precision.



At the same time, the researchers chose five different noise-level categories. These were ambient noise level, and low, medium, high and very high noise treatments.&nbsp; A total of 20 trials was carried out at each noise level. The noise levels corresponded to 115 dB, 119 dB, 126 dB, 135 dB and 150 dB respectively, as recorded adjacent to each dolphin’s underwater button.



The researchers found that Delta and Reece were able to coordinate their button-pushing to within one second of each other in 85 percent of trials at the ambient (lowest) noise level. As the levels of noise played from an underwater speaker increased, both dolphins compensated by increasing the volume and duration of their whistles. Reese’s whistles were on average 1.85 times longer in the highest noise exposure trials than in the ambient noise trials, and Delta’s whistles were on average 1.66 times longer in the very high noise trials than in the ambient noise trials.



In addition to “shouting” louder and longer, the dolphins also changed their body positions to face each other more often, and swam to the other side of the pool to be closer to one another. Despite these strategies to help them cope with the loud noise, they were only able to achieve a success rate of 62.5 percent in trials at the highest noise level.&nbsp;



“This shows us that, despite them using these compensatory mechanisms, their communication was impaired by noise,” explained study first author Pernille Sørensen of the University of Bristol. “Our work shows that, despite their attempts to compensate, despite being highly motivated and the fact that they know this cooperative task so well, the noise still impaired their ability to successfully coordinate.”



“Those same reasons that make sound so advantageous for animals to use also make them susceptible to disturbance from noise in the environment,” said Sørensen. “Within the last couple of decades, we’ve seen a dramatic increase in human-made noise, and noise pollution in the oceans is no exception.”



While this research was conducted with dolphins living in human care, human-generated noise can potentially have detrimental effects on wild dolphins, too. “If groups of animals in the wild are, for example, less efficient at foraging cooperatively, then this will negatively impact individual health, which ultimately impacts population health,” said study co-author Stephanie King, associate professor at the University of Bristol.



“Our work shows that these adjustments are not necessarily enough to overcome the negative effects of noise on communication between individuals,” said Professor King. Since dolphins rely on their communication skills to successfully hunt and reproduce, noise levels can affect their behaviors, which in turn affect population health.



“This collaboration with international colleagues at the Dolphin Research Center provided us with a unique opportunity to investigate the impact of noise on animals working together in a controlled setting, something that is almost impossible to do in the wild,” said Sørensen. To study this in the wild, the researchers would need further understanding of when animals are actively working together and how cooperative behavior is coordinated. “Our results clearly show the need to account for how noise affects group tasks in wild animals."



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Dolphins must "shout" over underwater noise to communicate

Dolphins are highly intelligent, social mammals that tend to form...

A team of researchers led by the <a href="https://illinois.edu/">University of Illinois Urbana-Champaign</a> has developed a new <a href="https://www.earth.com/news/dna-can-help-predict-ecosystem-changes-when-animals-are-reintroduced/">DNA</a>-collection method that allows scientists to capture genetic information from wildlife without disturbing the animals or putting their own lives into jeopardy. The experts tested this protocol on elephant dung and managed to collect enough DNA to sequence the whole genomes not only of the elephants, but also of the microbes, plants, and other organisms associated to them.



“We combined existing methodologies in such a way that we are now able to use noninvasive samples to generate genome-scale data,” said&nbsp;study lead author Alida de Flamingh, a postdoctoral researcher in Genetics and Ecology at Illinois. “This allows us to assess wildlife populations without having to dart, capture, or immobilize animals.”



According to study co-author Alfred Roca, a professor of Animal Sciences at the same university, collecting DNA from animal dung is not something new. “Elephant fecal samples have been used for decades to study the genetics of elephants,” he said. “But this relies on very cumbersome methods, often involving chemicals that in some cases may be dangerous. The collections are bulky, they’re hard to ship and they have to be refrigerated, making the whole process very costly.”



Now, the researchers tested a less expensive alternative: using small data-collection cards that have previously been treated to prevent the samples from degrading, allowing to store them for months without refrigeration.



First, the scientists collected and analyzed samples from zoo elephants to determine how long after defecation the fecal samples would still yield viable genomic data. The analysis revealed that even after 72 hours, the samples could be reliably used for genomic sequencing. In a next step, the team tested this procedure on samples collected from wild African savanna elephants. The sequencing led to treasure trove of information.



“I was surprised. I thought we might get some elephant DNA from the cards, but I was thinking on the order of two percent. However, on average, more than 12 percent of the DNA was attributed to the elephant,” Roca reported.&nbsp;



Since this was achieved without using costly and time-consuming laboratory methods that target only elephant DNA, each sample yielded a vast amount of information not only about the elephants, but also the microbial composition of their guts, their habitat, and diet.



“It’s really beneficial to get an idea of everything that’s in there because now you can start asking questions, not only about elephant genomes but also about things like their health, their diet and whether there are pathogens or parasites present,” de Flamingh explained.



According to the researchers, when it comes to elephant genomes, the results are comparable with – or even better than - those obtained from blood samples. “You can explore the connectivity of different elephant populations, the level of genetic diversity, the level of inbreeding and relatedness among elephants. And I would say there are lots of reasons you don’t want to have to collect blood samples from wild elephants,” Roca said.



“It’s possible to do what you could do with blood, but it goes beyond that. You now can do analyses that you couldn’t do before with blood DNA, which only provides information about the elephant’s genome,” de Flamingh concluded.



The study is published in the journal <a href="http://dx.doi.org/10.3389/fgene.2022.1021004">Frontiers in Genetics</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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New DNA-collection method is harmless to wildlife

A team of researchers led by the University of Illinois...

As humans, we share many characteristics with other primates, such as <a href="https://www.earth.com/news/bonobos-early-human-evolution/">bonobos</a>, who – together with chimpanzees – are the ape species most closely related to us. While there are many similarities in the social behavior of bonobos and humans, a team of researchers led by <a href="https://www.universiteitleiden.nl/en">Leiden University</a> and the <a href="https://www.uva.nl/">University of Amsterdam</a> has recently found that there are also remarkable differences.&nbsp;



The experts discovered that, although both species are more interested in photos of conspecifics that show emotion than in neutral photos, human attention is more easily drawn to photos of family members or friends, whereas the attention of bonobos is drawn to the emotion of individuals they don’t know.



In a first experiment, the scientists trained bonobos from the <a href="https://apenheul.nl/">Apenheul</a> zoo to press a dot on a screen. After pressing it, two images appeared briefly that showed bonobos from the same group as well as unfamiliar conspecifics. While some images were neutral, others expressed emotions related to fear, play, or sex. Then, a dot appeared again behind one of the two images, and the bonobos had to touch it as quickly as possible in order to receive a food reward. 



The researchers kept track of how fast the bonobos pressed the dot that appeared after seeing the different pictures, with the presupposition that the apes would be faster at touching the dot behind the photo that immediately grabs their attention.



A second experiment presented people visiting the zoo with the same task, with photos of strangers or a person with whom they visited the zoo that day, and with varying facial expressions, such as neutral, happy, angry, or scared.&nbsp;



“In these studies, we saw that both humans and bonobos react more quickly to photos of conspecifics with an emotional charge than neutral photos,” said study lead author Evy Van Berlo, a postdoctoral researcher in Cognitive Behavioral Ecology at the University of Amsterdam. “That is what we expected: it makes sense given that we are both social animals. Yet there was also a remarkable difference. We humans are mainly focused on emotionally charged photos of people we know, while the attention of bonobos is focused on studying emotionally charged photos of unfamiliar others.”



According to the researchers, this evolutionary difference has probably emerged due to differences in the living environment of the two species. “Bonobos live in a relatively stable ecological environment in Congo, where there is enough food available. Under those circumstances, there is less need for competition with other groups and peaceful interaction with strangers might even be beneficial for the conservation of the species. Early humans, on the other hand, lived in nomadic groups that had to compete with other groups of humans for food. Under such circumstances, it is probably evolutionarily more beneficial to favor individuals from your own group over strangers,” Van Berlo explained.



In future research, the scientists plan to repeat this study with other species of great apes with different social organizations, such as chimpanzees, which are more competitive, male-dominated, and socially stratified. “With chimpanzees, for example, I would expect them to be more interested in the emotions of individuals they know than the emotions of strangers,” Van Berlo concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1037/emo0000882">Emotion</a>.



—



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Bonobos are more interested in the emotions of strangers

As humans, we share many characteristics with other primates, such...

From a biological perspective, islands are special places. Their isolation from mainlands leads to more rapid <a href="https://www.earth.com/news/new-study-changes-our-understanding-of-mammal-evolution/">evolution</a> and results in the formation of unique forms of plants and animals that are found nowhere else on Earth. Madagascar is one such island. It is the fifth largest island in the world, and is known for its diversity of endemic and unique species. Sadly, many of these species are now threatened with extinction as they struggle to adapt to habitat loss, exploitation and climate change.



Approximately 90 percent of all Malagasy plants and animals occur on this island and nowhere else. Among the mammals there are more than 100 endemic species of lemurs, which are adapted to the many different habitats found on the island. There is also the cat-like fossa, which is a formidable predator, and in excess of 20 species of tenrecs. The remarkable diversity of unique animals and plants reflects the fact that the island has been isolated for about 88 million years after it split from the Indian landmass.



A team of biologists and paleontologists from Madagascar, Europe and the United States set out to understand the extent to which Madagasy mammals have been perturbed by human disturbance. They were concerned that so many of the mammal species are facing threats to their existence and set out to ascertain exactly what is at stake if environmental change and human pressures on the island wildlife continue.



The team, led by biologists from the University of Groningen (Netherlands), Naturalis Biodiversity Center (Netherlands) and the Association Vahatra (Madagascar), first established a new dataset describing the evolutionary relationships of all 249 species of mammals that were present on Madagascar at the time that humans settled permanently on the island, around 2,500 years ago. They established that of the 249 mammal species, 30 are now extinct, and a further 120 are listed in the IUCN’s Red List as threatened with extinction.



The experts estimated how long it took all these species to evolve from their common ancestors, and could then extrapolate how long it took this level of biodiversity to evolve. In this way the researchers predicted the length of time it would take for evolutionary processes to “replace” all the endangered mammals, if they were to go extinct.&nbsp;



Using a computer simulation model based on island biogeography theory, the team found that it would take approximately 3 million years to regain the number of mammal species already lost from Madagascar in the time since humans arrived. However, if currently threatened species go extinct, it would take much longer: about 23 million years of evolution would be needed to recover the same number of species.&nbsp;



Put simply, this is really bad news. “It's abundantly clear that there are whole lineages of unique mammals that only occur on Madagascar and that have either gone extinct or are on the verge of extinction, and if immediate action isn't taken, Madagascar is going to lose 23 million years of evolutionary history of mammals, which means whole lineages unique to the face of the Earth will never exist again,” said study co-author Steve Goodman, MacArthur Field Biologist at Chicago’s <a href="https://www.fieldmuseum.org/">Field Museum</a> and Scientific Officer at Association Vahatra in Antananarivo.



The staggering time it would take to recover this diversity surprised the scientists: “It is much longer than what previous studies have found on other islands, such as New Zealand or the Caribbean,” said lead researcher Luis Valente.&nbsp;



The results of this new research, published in the scientific journal&nbsp;<a href="http://dx.doi.org/10.1038/s41467-022-35215-3">Nature Communications</a>, suggest Madagascar has reached a biodiversity tipping point and that an extinction wave with deep evolutionary impact is imminent unless immediate conservation actions are taken. However, the study finds that, with adequate conservation action, we may still preserve over 20 million years of unique evolutionary history on the island.&nbsp;



“It was already known that Madagascar was a hotspot of biodiversity, but this new research puts into context just how valuable this diversity is. These findings underline the potential gains of the conservation of nature on Madagascar from a novel evolutionary perspective," said Valente.



That doesn’t mean that, if we let all of the lemur, tenrecs, fossas and other unique Malagasy mammals go extinct, evolution will recreate them if we just wait around for 23 million more years. “It would be simply impossible to recover them,” said Goodman. Instead, the model means that to achieve a similar level of evolutionary complexity, whatever those new species might look like, would take 23 million years.



This urgent conservation work is made difficult by inequality and political corruption that keeps land-use decisions out of the hands of most Malagasy people, noted Goodman. “Madagascar’s biological crisis has nothing to do with biology. It has to do with socio-economics.” But while the situation is dire, “we can't throw in the towel. We’re obliged to advance this cause as much as we can and try to make the world understand that it’s now or never.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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It's "now or never" for Madagascar’s endangered mammals

From a biological perspective, islands are special places. Their isolation...

As more and more of the world’s population moves to cities, the extent of the land occupied by urbanization increases. Currently, approximately 56 percent of people (4.4 billion) on Earth live in cities, and this is set to increase to over six billion by 2050. Urbanization brings radical changes to landscapes and ecosystems, and results in significant losses in biodiversity. However, some species can adapt to life in these areas, and may even thrive.&nbsp;



A study of Puerto Rican crested <a href="https://www.earth.com/news/anole-lizards-have-lungs-that-develop-in-less-than-two-days/">anoles</a> in three cities and three adjacent forested regions has now shown that these lizards have adapted morphologically to life in urban environments, and that their adaptations are reflected in their genomes.



“Urbanization impacts roughly two-thirds of the Earth and is expected to continue to intensify, so it’s important to understand how organisms might be adapting to changing environments,” said study first author Professor Kristin Winchell of <a href="https://www.nyu.edu/">New York University</a>. “In many ways, cities provide us with natural laboratories for studying adaptive change, as we can compare urban populations with their non-urban counterparts to see how they respond to similar stressors and pressures over short periods of time.”



Crested anoles (Anolis cristatellus) are small-bodied lizards&nbsp;that are commonly found in both urban and forested areas in Puerto Rico. Prior studies by Winchell and her colleagues found that urban&nbsp;Anolis cristatellus&nbsp;have evolved certain traits that are beneficial to them in cities. They have larger toe pads with more specialized scales that allow them to cling to smooth surfaces, like walls and glass, and have longer limbs that help them sprint across open areas.&nbsp;



In the current study, published in the journal&nbsp;<a href="http://dx.doi.org/10.1073/pnas.2216789120">PNAS</a>, the researchers looked at 96&nbsp;Anolis cristatellus&nbsp;lizards from three regions of Puerto Rico – San Juan, Arecibo, and Mayagüez – and compared lizards living in urban centers with those living in forests surrounding each city.&nbsp;They investigated whether the physical adaptations were similar in lizards from all three cities, and analyzed their genomes to establish genetic differences between urban-dwelling and forest-dwelling lizards in each region.



After confirming that the lizard populations in the three regions were genetically distinct from each other, they measured the toe pads and leg lengths of all 96 lizards that they collected. They found that the urban lizards did indeed show similar morphological changes in all three cities, including having significantly longer limbs and larger toe pads, with more specialized scales on the toes, than did the forest lizards.&nbsp;



The researchers were able to conclude that these similarities could be attributed to similar environmental pressures on lizards that lived in the cities, and that the evolution of these traits helped urban lizards to survive and thrive.&nbsp;



Furthermore, analysis of exome DNA (the regions of the genome that code for production of proteins) revealed that there was a genetic basis for the physical changes observed in the urban-living lizards. The researchers identified a set of 33 genes, found in three regions of the lizard genome, that were repeatedly associated with urbanization across populations, including genes related to immune function and metabolism.



“While we need further analysis of these genes to really know what this finding means, we do have evidence that urban lizards get injured more and have more parasites, so changes to immune function and wound healing would make sense. Similarly, urban anoles eat human food, so it is possible that they could be experiencing changes to their metabolism,” said Professor Winchell.



In additional analysis, the researchers found 93 genes in the urban lizards that are important for limb and skin development, offering a possible genetic explanation for the increases in their leg lengths and toe morphology.&nbsp;



“The physical differences we see in the urban lizards appear to be mirrored at the genomic level,” said Professor Winchell. “If urban populations are evolving with parallel physical and genomic changes, we may even be able to predict how populations will respond to urbanization just by looking at genetic markers.”



Animals that adapt to living in urban environments typically experience a change in diet and probably an increased ambient temperature, since urban areas are often “heat islands” when compared to surrounding rural areas. Urban animals would thus be expected to show changes in behavior and metabolism, as well as increased tolerance of heat.&nbsp;



“Understanding how animals adapt to urban environments can help us focus our conservation efforts on the species that need it the most, and even build urban environments in ways that maintain all species."



Do the differences in urban lizards apply to people living in cities? Not necessarily, according to Professor Winchell, as humans aren’t at the whim of predators like lizards are. But humans are subject to some of the same urban factors, including pollution and higher temperatures, which seem to be contributing to adaptation in other species.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Urban lizards show physical and genetic adaptations

As more and more of the world’s population moves to...

Parasites may fill us with revulsion and disgust, but they are integral components of ecosystems and play important ecological roles. They regulate host populations, and influence food webs, competition and <a href="https://www.earth.com/news/biodiversity-at-risk-from-palm-oil-expansion/">biodiversity</a>, even shaping community and ecosystem structure. In fact, there are way more parasitic species than there are predators, indicating how widespread this life-history strategy is in nature.&nbsp;



However, while we are deeply concerned about the impacts of global warming on the species we value (think birds and mammals), we don’t often imagine how the world’s parasites will be affected. In a new study, researchers from the <a href="https://www.washington.edu/">University of Washington</a> and colleagues have made use of fish specimens preserved in museum collections over the past 140 years to assess long-term trends in parasite populations.&nbsp;



“People generally think that climate change will cause parasites to thrive, that we will see an increase in parasite outbreaks as the world warms,” said lead author&nbsp;<a href="https://environment.uw.edu/faculty/chelsea-wood/">Chelsea Wood</a>, a UW associate professor of aquatic and fishery sciences. “For some parasite species that may be true, but parasites depend on hosts, and that makes them particularly vulnerable in a changing world where the fate of hosts is being reshuffled.”



The current study focused on eight species of fish caught in Puget Sound, the second largest estuary on mainland U.S. These species are common in the collections of natural history museums and most of the specimens came from the UW Fish Collection at the Burke Museum of Natural History and Culture. While mammals and birds are preserved with taxidermy, which retains parasites only on skin, feathers or fur, fish are preserved in fluid, which enters their tissues and thus also preserves any parasites living inside them at the time of their death.&nbsp;



The researchers had to dissect and open up the preserved fish specimens and identify any parasites they found inside the body. They counted the parasites before returning the specimens to the preserving fluid. In total, the scientists found 17,259 parasites, of 85 types, in the 699 fish specimens.



“It took a long time. It’s certainly not for the faint of heart,” said Professor Wood. “I’d love to stick these fish in a blender and use a genomic technique to detect their parasites’ DNA, but the fish were first preserved with a fluid that shreds DNA. So what we did was just regular old shoe-leather parasitology.”



The results of the study show that, for some parasite species, numbers decreased dramatically between 1880 and 2019, in fish from Puget Sound. These parasites included multicellular species of arthropods (animals with an exoskeleton), such as crustaceans, as well as what Wood describes as “unbelievably gorgeous tapeworms:” the&nbsp;Trypanorhyncha, whose heads are armed with hook-covered tentacles.&nbsp;



Those parasite species that suffered the largest population declines were the ones that are dependent on three or more host species during their lifecycle. Some parasites have a single host species, but most require more than one and will travel between host species. For example, the eggs of some parasites are carried in one host species, the larvae emerge and infect another host and the adult may reach maturity in a third host before laying its own eggs.



For parasites that rely on three or more host species during their lifecycle – including more than half the parasite species identified in the study’s Puget Sound fish – analysis of historic fish specimens showed an average decline in abundance of 11 percent per decade. Of 10 parasite species that had disappeared completely by 1980, nine relied on three or more hosts.&nbsp;



“Our results show that parasites with one or two host species stayed pretty steady, but parasites with three or more hosts crashed,” said Professor Wood. “The degree of decline was severe. It would trigger conservation action if it occurred in the types of species that people care about, like mammals or birds.”



“Parasite ecology is really in its infancy, but what we do know is that these complex-lifecycle parasites probably play an important role in pushing energy through food webs and in supporting top apex predators,” added Wood, who is one of the authors of a 2020 report laying out&nbsp;<a href="https://www.washington.edu/news/2020/08/03/new-studies-show-how-to-save-parasites-and-why-its-important/">a conservation plan for parasites</a>.



To understand the possible causes of these declines, the researchers investigated three factors over the 140 year time span; the abundance of the fish species in Puget Sound, pollution levels in the estuary, and water temperature at the ocean surface. The variable that best explained the decline in parasites was sea surface temperature, which rose by 1 degree Celsius (1.8 degrees Fahrenheit) in Puget Sound between 1950 and 2019.



For the parasite species that require multiple hosts to complete their lifecycle, warming temperatures just need to affect one of the hosts and this will prevent the parasite from reproducing successfully. These parasites are thus vulnerable to disruption at any point along the way.&nbsp;



“This study demonstrates that major parasite declines have happened in Puget Sound. If this can happen unnoticed in an ecosystem as well studied as this one, where else might it be happening?” Wood said. “I hope our work inspires other ecologists to think about their own focal ecosystems, identify the right museum specimens, and see whether these trends are unique to Puget Sound, or something that is occurring in other places as well.”



“Our result draws attention to the fact that parasitic species might be in real danger. And that could mean bad stuff for us – not just fewer worms, but less of the parasite-driven ecosystem services that we’ve come to depend on.”



The research is published in the journal&nbsp;<a href="http://dx.doi.org/10.1073/pnas.2211903120">Proceedings of the National Academy of Sciences</a>.&nbsp;



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Marine parasites are vulnerable to warming oceans

Parasites may fill us with revulsion and disgust, but they...

According to recent reports from organizations such as BirdLife International, more than half of all shorebird populations are currently in a state of decline. Despite being a global phenomenon, the driving factors behind the dwindling numbers of sandpipers, plovers, avocets, oystercatchers, and other shorebirds remain unidentified.



In a new study, researchers at the <a href="https://www.ulisboa.pt/en">University of Lisbon</a> have pinpointed environmental changes that may help to explain why shorebirds are vanishing.



"Shorebird declines are occurring worldwide but the causes are not fully understood," wrote the study authors. "Recent literature suggests that the deterioration of habitat quality at their non-breeding areas, mostly located in temperate and tropical coastal wetlands, might be a major contributing factor. However, most studies carried out so far tend to be restricted to a few regions."



"Remote sensing can help correct such geographical bias on knowledge by providing a standardized approach on how shorebird habitats have been changing over the last few decades at a global scale."



The team used remote sensing data to analyze <a href="https://www.earth.com/news/wooden-shipwrecks-have-become-diverse-microbial-habitats/">habitat</a> changes in 907 sites - known as Important Bird and Biodiversity Areas (IBAs) - over the last two decades. The researchers were especially focused on changes in low tide feeding areas and high tide roosting areas.&nbsp;



"Globally, supratidal areas (used as roosting habitat) have changed more significantly than tidal flats (used as feeding habitat). Yet, we found striking losses of tidal flats in IBAs distributed in several regions of the East Asian - Australasian Flyway," wrote the researchers.



"At supratidal areas, there was a general expansion of marshland, grassland and urban areas, contrasting with a decline of barren land, woodland and cropland. The expansion of marshland occurred in IBAs of most regions of the world. Urban areas also expanded consistently in supratidal areas within the most populated regions of the world."



The experts noted that the loss of barren land is particularly concerning as it may translate into a loss of high-quality roosts. According to the study, changes may be urgently needed to save some species of the East Asian - Australasian Flyway that are facing population collapses due to habitat loss.



“This global approach is a step forward to understand the causes of shorebird declines, a group of birds that is already threatened," said study lead author Carlos David Santos. “Many species of this group are long-distance migrants, some moving more than 20.000 km annually, thus they can be affected by environmental changes occurring at different regions of the world - this is why a global analysis of such changes was so important."



The research was a collaboration between experts from the Centre for Environmental and Marine Studies (CESAM) and the Centre for Ecology, Evolution and Environmental Changes (cE3c) at Ciências ULisboa.



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.scitotenv.2022.159707">Science of The Total Environment</a>.



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New clues about the mysterious decline of shorebirds

According to recent reports from organizations such as BirdLife International,...

The end-Permian <a href="https://www.earth.com/news/the-sixth-mass-extinction-is-currently-in-progress/">mass extinction</a> from 250 million years ago is the most severe of the five mass extinctions our planet faced, decimating over 80 percent of marine and terrestrial plant and animal species. This catastrophic loss of biodiversity was triggered by the emplacement of a continental-scale volcanic eruption covering much of modern-day Siberia, which released massive amounts of carbon from the Earth’s interior into the atmosphere, generating a devastating global warming event that led to the collapse of the ozone layer.



Now, an international team of scientists has discovered that pollen preserved in rocks dating from that period contained compounds that function like sunscreen and were produced by plants to protect them from harmful ultraviolet radiation (UV-B). These findings suggest that a pulse of UV-B may have played an important role in the end-Permian mass extinction.



“Plants require sunlight for photosynthesis but need to protect themselves and particularly their pollen against the harmful effects of UV-B radiation. To do so, plants load the outer walls of pollen grains with compounds that function like sunscreen to protect the vulnerable cells to ensure successful reproduction,” explained Barry Lomax, a professor of Plant Paleobiology at the <a href="https://www.nottingham.ac.uk/">University of Nottingham</a>. &nbsp;



“We have developed a method to detect these phenolic compounds in fossil pollen grains (Alisporites-type) recovered from southern Tibet and detected much higher concentrations in those grains that were produced during the end-Permian mass extinction and peak phase of volcanic activity,” added Liu Feng, a paleontologist at the <a href="http://english.nigpas.cas.cn/">Nanjing Institute of Geology and Palaeontology</a>.



The researchers discovered an increase in UV-B-absorbing compounds (UACs)&nbsp;which coincided with a massive rise in mercury concentration and a decrease in carbon isotopes in the latest Permian deposits, suggesting a close temporal link between large-scale volcanic eruptions, worldwide carbon- and mercury-cycle perturbations, and disruptions of the ozone layer. Thus, elevated UV-B levels most likely exerted far-reaching and long-lasting impacts on the entire planet, reducing plant biomass and terrestrial carbon storage and exacerbating global warming. Moreover, increased concentrations of phenolic compounds made plant tissue harder to digest, making an already hostile environment even more challenging for herbivores.



“Volcanism on such a cataclysmic scale influences all aspects of the Earth system, from direct chemical changes in the atmosphere, through changes in carbon sequestration rates, to reducing the volume of nutritious food sources available for animals,” concluded Wes Fraser, an expert in Organic Geochemistry at <a href="https://www.brookes.ac.uk/">Oxford Brookes University</a>.



The study is published in the journal <a href="http://dx.doi.org/10.1126/sciadv.abo6102">Science Advances</a>.&nbsp;&nbsp;&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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UV radiation played a role in Earth's largest mass extinction

The end-Permian mass extinction from 250 million years ago is...

The Madidi National Park and Natural Integrated Management Area (PNANMI), in Bolivia, is among the most biodiverse areas in the world. Formed in 1995 in the upper Amazon River basin, the area has an extent of 18,958 km² and ranges in altitude from less than 200 m on the Amazonian floodplain to more than 6 000 m in the high Andes. It is home to an astonishing array of living creatures, including 5,535 species of plants, 1,633 species and subspecies of butterflies, and 1,830 species of vertebrates.&nbsp;



In 2015, the Wildlife Conservation Society of Bolivia commenced an initiative, known as Identidad Madidi, to survey and record the plants and wildlife present in the National Park and Natural Integrated Management Area. They wished to ascertain whether the region was indeed the most biodiverse protected area in the world, as they suspected. In addition, they aimed to inform the people of Bolivia about their natural heritage by means of an educational campaign, as well as traditional and social media.&nbsp;&nbsp;



With specialists from the <a href="https://www.wcs.org/">Wildlife Conservation Society</a> of Bolivia, the Institut de Recherche pour le Développement de Montpellier (France) and the National Museum of Natural History and the Ecology Institute of the Universidad Mayor de San Andrés, the Identidad Madidi team conducted fieldwork between 2015 and 2018. They visited 13 different sites and collected fish specimens by means of electrofishing, gillnets, trawls, line and hook, and ichthyoplankton nets (for fish larvae and eggs).&nbsp;



The researchers have now published the results of their fish survey in the journal <a href="https://editorial-inia.com/wp-content/uploads/2022/12/NHAC023_Miranda_2022.pdf">Neotropical Hydrobiology and Aquatic Conservation</a>, where they report that the fish species list for Madidi now totals 333, more than double the number previously known from the region. In addition, the researchers suspect that as many as 35 of these species are brand new to science.&nbsp;



Before the start of the Identidad Madidi expedition, the researchers went through literature pertaining to earlier fish surveys in Madidi and found that 161 species had been recorded for the area. They added a further 172 species during the Identidad Madidi fieldwork, with 21 of them being identified from eggs or larvae alone. They say that this total of 333 species makes the PNANMI Madidi the richest Bolivian protected area for fish.&nbsp;



Species range in size from the invasive arapaima (Arapaima gigas), a mouth-breathing giant weighing more than 200 kg and measuring over 3 m, to the seasonally abundant killifish (Anablepsoides beniensis) that are found in pools in natural savannas and are just 1.5 cm long. The list also includes the most attractive gamefish from the Amazon, the golden dorado (Salminus brasiliensis), as well as migratory catfish, from the Amazonian goliath catfish (Brachyplatystoma filamentosum) to the tiny chipi chipi pencil catfish (Trichomycterus barbouri) whose massive collective migration is a&nbsp;<a href="https://www.youtube.com/watch?v=pNvCOl_zjho">local phenomenon</a>.&nbsp;



Another killifish (Orestias&nbsp;sp.) is found in some of the highest Andean lakes at 4,300 m in Madidi, while in the stagnant ponds of the wonderful Amazon, electric knife fish (Gymnotus carapo) and swamp eels (Synbranchus madeirae) occur. In the fast-flowing streams of the Amazon headwaters, several different species of naked catfish (Astroblepus&nbsp;spp.) are found, including some that are likely to be new species for science.



The 35 possible new species include candidates from the genera Knodus, Microgenys, Moenkhausia, Characidium, Apareiodon, Brachyhypopomus, Ernstichthys&nbsp;(genus reported for the first time in Bolivia), Astroblepus and Trichomycterus&nbsp;(including one species recently described and named in honor of a pioneer French ichthyologist in Bolivia). In addition, a three-barbled catfish (Cetopsorhamdia), a striking pike cichlid (Crenicichla) and a charming bumblebee catfish (Microglanis) are also among the brand new species.&nbsp;



The researchers recorded four alien species (1.2 percent) as being present in the PNANMI Madidi, and report that they also identified fish species from four genera that have never been listed in Bolivia before. The largest number of species are found in the order Characiformes (139 species; 41.7 percent), followed by Siluriformes (137 species; 41.1 percent), and Cichliformes (19 species; 5.7 percent), which together represent 88.6 percent of species richness.&nbsp;



“With an extension of 18,957.5 square kilometers (7,319 square miles), Madidi covers 1.3 percent of the Madeira River basin, but conserves 25 percent of the known species in the basin. Madidi also represents only 1.8 percent of the Bolivian territory, but it conserves almost 40 percent of the ichthyofauna recorded in Bolivia," said lead author Guido Miranda. "This study has more than doubled our knowledge about fish diversity in this incredible protected area, but with several sub-basins yet to sample in the park, this is only the beginning.”



Madidi is one of the most important protected areas in Bolivia and the world because of its extraordinary biological richness, which is expressed in its diversity of ecosystems and flora and fauna species. It contains 13 major vegetation types, including the best example of pristine savannas and the largest and best-preserved montane forests in Bolivia.



“Due to its great diversity of habitats, mostly as a result of the altitudinal gradient from 184 meters (Heath River) to 6,044 meters (Chaupi Orko Peak), Madidi is considered the most biodiverse protected area on the planet. The Identidad Madidi initiative aimed to firmly establish this record-breaking status for the park, whilst communicating the importance of Madidi to the Bolivian people," said study co-author Dr. Rob Wallace. "This is the first of several biodiversity summary articles that the Bolivian scientists on the expedition are systematizing to share the results of our efforts with Bolivia and the world.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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More than 300 fish species found in Madidi National Park

The Madidi National Park and Natural Integrated Management Area (PNANMI),...

It is accepted that birds evolved from <a href="https://www.earth.com/news/past-climate-change-drove-the-rapid-evolution-of-reptiles/">reptiles</a>, and particularly from small, carnivorous theropod dinosaurs, and that this process did not take place in one burst of evolution. Rather, the huge morphological changes happened in steps, over tens of millions of years, with the typical bird features evolving at different rates, for distinct purposes, and ending up giving the characteristic modern bird body plan. However, paleontologists still wonder how it was that all these dramatic transformations took place.&nbsp;



A new bird fossil, found in the Jiufotang Formation of Liaoning Province in China, has now been analyzed by paleontologists from the <a href="https://english.cas.cn/">Chinese Academy of Sciences</a> in Beijing, and has shown to be a bizarre mixture of dinosaur and bird features. It is dated at around 120 million years and combines a typical bird body with a reptilian skull that is similar in morphology to the skull of Tyranosaurus rex. This finding supports the idea that evolutionary changes in morphology did not take place at the same rate in all body structures during early bird diversification.&nbsp;



“The Cretaceous period is a critical time interval that encompasses explosive diversifications of terrestrial vertebrates, particularly the period when the earliest-branching birds, after divergence from their theropod ancestors, evolved the characteristic avian bauplan that led eventually to their global radiation,” said Dr. WANG Min, a researcher with the Institute of Vertebrate Paleontology and Paleoanthropology and the Center for Excellence in Life and Paleoenvironment at the Chinese Academy of Sciences.



Named Cratonavis zhui, this new species is positioned on the avian evolutionary tree, somewhere between the more reptile-like, long-tailed&nbsp;Archaeopteryx&nbsp;and the Ornithothoraces (which include modern birds and their closest ancestors). Its features include wings, feathers, claws on the wings, conical teeth, and the absence of a long, bony tail. In addition, the fossil bird has unusually elongated scapulae and first metatarsal bones, features that are, so far, unique to this species alone.



The researchers used high-resolution computed tomography (CT)-scanning to analyze the fossilized bones, and then they “removed” these, digitally, from their rocky tomb, repositioned them and reconstructed the original shape of the post-cranial skeleton and skull. They found that, while the skeleton was typically bird-like, the skull retained small, conical teeth, along with the feature known as akinesis, which is characteristic of dinosaurs and other reptiles, but not of modern birds.&nbsp;



“The primitive cranial features speak to the fact that most Cretaceous birds, such as&nbsp;Cratonavis,&nbsp;could not move their upper bill independently with respect to the braincase and lower jaw, a functional innovation widely distributed among living birds that contributes to their enormous ecological diversity,” said Dr. LI Zhiheng, a lead author of the study.



As for the bizarre scapula and first metatarsal bone in Cratonavis, Dr. WANG Min, a lead and corresponding author of this study, said: “The scapula is functionally vital to avian flight, and it conveys stability and flexibility. We trace changes of the scapula across the theropod-bird transition, and posit that the elongate scapula could augment the mechanical advantage of muscle for humerus retraction/rotation, which compensates for the overall underdeveloped flight apparatus in this early bird, and these differences represent morphological experimentation in volant behaviour, early in bird diversification.”



In their report, published in&nbsp;<a href="http://dx.doi.org/10.1038/s41559-022-01921-w">Nature Ecology &amp; Evolution</a>, the paleontologists conclude that the elongated first metatarsals in the fossil bird’s feet were subjected to selection pressure during the dinosaur-bird transition, and ended up becoming shorter. They then lost their evolutionary lability (changeability) once they reached their optimal size, less than a quarter of the length of the second metatarsal.&nbsp;



“However, increased evolutionary lability was present among Mesozoic birds and their dinosaur kins, which may have resulted from conflicting demands associated with its direct employment of the hallux [innermost digit of the hind foot] in locomotion and feeding,” said co-author Dr. Thomas Stidham. For&nbsp;Cratonavis, such an elongated hallux may have been advantageous while hunting for prey.



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Puzzling fossil has the body of a bird, skull of a dinosaur

It is accepted that birds evolved from reptiles, and particularly...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

[sendtonews key="0ynNMYkMKa-2340414-12187" type="single"] Today’s Video of the Day from the...

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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

Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



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Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Two distant planets may be "water worlds"

[sendtonews key="QIoVYJqRBi-2434608-12187" type="single"] Today's Video of the Day from NASA...

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Satellites capture the world's biggest and fastest waves

[sendtonews key="MHyhtebibJ-2200368-12187" type="single"] Today’s Video of the Day from NASA...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...