Episiphon filum

Sometimes the common names for <a href="https://www.earth.com/news/grazing-animals-play-a-key-role-in-stabilizing-soil-carbon/">animals</a> can end up being rather confusing. For example, guinea pigs are not related to pigs and neither are they native to Guinea. In the case of American black bears, not all of them are black. In fact, they come in a range of colors, including brown (also known as cinnamon), blond, or bluish-grey, and some even have coats with mixed colors.&nbsp;



Scientists have wondered why there is this diversity in coat color among black bears. Some have hypothesized that the cinnamon coat is a way of mimicking the generally larger grizzly bear (Ursus arctos), which is brown (but can also be black!) This may provide some form of camouflage or defense for the American black bears.&nbsp;



In new research from scientists at <a href="https://www.hudsonalpha.org/">HudsonAlpha</a>, the University of Memphis, and the University of Pennsylvania, the answer to this question has been discovered in the genomes of the black bears, and it involves a mutation in a pigment gene that happened a very long time ago. The research paper is published in the journal <a href="https://www.cell.com/current-biology/home">Current Biology</a>.



Dr. Emily Puckett is an assistant professor of Biological Sciences at the University of Memphis. She has devoted her career to learning more about the evolution and genetics of bears. With help from partners in state, provincial, and federal wildlife agencies, she collected hundreds of DNA and hair samples from North American bears. Dr. Puckett teamed up with Dr. Greg Barsh, an animal pigmentation expert at HudsonAlpha, to figure out why black bears aren’t always black.



Melanin is the pigment that gives mammals their coat colors. It is produced in the skin by cells known as melanocytes. There are two types of melanin: eumelanin is black or brown, and pheomelanin is red or yellow. It is widely accepted that genetic variation in melanin biosynthesis is what gives rise to differences in hair, eye, and skin color.&nbsp;



The researchers studied photos of bears and analyzed their hair samples. They found that the cinnamon-colored black bears produce reduced amounts of eumelanin, just like grizzly bears. They then sequenced the genomes of nearly 200 bears and identified several different missense mutations in the gene&nbsp;called TYRP1&nbsp;that codes for making the enzyme tyrosinase-related protein 1.&nbsp;



Cinnamon-colored black bears have a mutation called&nbsp;TYRP1R153C,&nbsp;while most (but not all) grizzly bears have a mutation called&nbsp;TYRP1R114C. The&nbsp;TYRP1&nbsp;gene produces the enzyme within the melanocytes, and this enzyme helps produce eumelanin, which explains why the cinnamon and grizzly bears have less of this specific pigment.&nbsp;



In addition, studies carried out in the lab of Dr. Mickey Marks at the University of Pennsylvania determined that the TYRP1R153C and TYRP1R114C&nbsp;mutations interfere with melanin synthesis and distribution.



“When we looked at other species, we were surprised to find the&nbsp;TYRP1R153C&nbsp;variant responsible for cinnamon&nbsp;U. americanus&nbsp;is identical to one previously described as a cause of oculocutaneous albinism (OCA3) in humans,” says Dr. Barsh. OCA3 is characterized by reddish skin and hair and frequent visual abnormalities and is most common in people of African or Puerto Rican ancestry. But according to Puckett, bears with&nbsp;TYRP1&nbsp;mutations have normal skin and can see just fine.



The&nbsp;TYRP1R153C&nbsp;variant was primarily found in bears from the southwest United States, and at lower frequencies moving northward to Southeast Alaska and the Yukon Territory.&nbsp;The TYRP1R153C&nbsp;mutation was associated with the cinnamon color in black bears, as well as with the chocolate and light brown colors, meaning it accounts for almost all of the color diversity among&nbsp;U. americanus.



The researchers used their data to learn more about the&nbsp;TYRP1R153C&nbsp;mutation. One hypothesis is that it may first have occurred in grizzly bears and then been&nbsp; transferred to black bears, but demographic analysis indicated that this was not what happened. Instead, the&nbsp;TYRP1R153C&nbsp;mutation arose spontaneously about 9,360 years ago in black bears living in the western United States, then spread as the bears moved and became distributed across their current geographic range.



“Based on its wide range today, the&nbsp;TYRP1R153C&nbsp;mutation that arose in black bears over 9,000 years ago probably gave an advantage to the cinnamon-colored bears,” says Dr. Puckett. “We used genetic modeling and simulations to predict the selective forces acting on the cinnamon morph. But our predictions ruled out the grizzly mimicry hypothesis as well as another hypothesis having to do with thermoregulation.”



The research team proposed a new explanation for the persistence of the coat color variant: crypsis. This refers to the ability of an animal to conceal itself by blending into the surrounding environment, usually by having similar coloration or patterning as the background. The researchers suggest that this is not only important for prey species or ambush predators, but also for large-bodied species that need to blend into their habitat.&nbsp;



“These results illustrate how genetic variation in melanin biosynthesis can underlie iconic phenotypes and inform our understanding of color variation and recent evolution in large carnivores,” says Dr. Barsh.



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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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Why are some black bears actually brown?

Sometimes the common names for animals can end up being...

A new study led by&nbsp;the&nbsp;<a href="https://www.nord.no/en/Pages/default.aspx">Nord University</a> in Norway in collaboration with the&nbsp;<a href="https://www.icm.csic.es/es">Institut de Ciències del Mar</a>&nbsp;(ICM-CSIC) in Spain has found that the rise in <a href="https://www.earth.com/news/arctic-temperatures-rise-when-plants-stop-breathing/">temperature</a> in the Arctic and sub-Arctic regions caused by global warming are promoting the settlement in these areas of species that previously lived in warmer, southern regions. These findings suggest that climate change is leading to a redistribution of species not only in the much more studied warmer areas of our planet, but also in colder regions which are warming at a much faster rate than the rest of the planet.



The scientists collected data from over 20,000 trawl surveys in the Norwegian and Barents Seas between 1994 and 2020. “In 1994, an average of eight fish species were caught in each trawl in the Norwegian and Barents Seas, while in 2020 the number rises to more than 13, which represents an increase of 66 percent. The results of the study also shown increases, albeit less significant, in the richness of adjacent areas,” said study lead author&nbsp;Cesc Gordó-Vilaseca, a doctoral student in Biosciences at the Nord University.&nbsp;



The analysis revealed that, of the 193 species included, 71 relatively warm-water species are now more common in the Arctic and sub-Arctic regions, while 23 species which were previously more common in the north are now occurring there less frequently. However, the study also documented the expansion of some Arctic species that seem to adapt well to rising temperatures, such as the commercially valuable common cod (Gadus morhua).&nbsp;



“The shift in frequency of species, sometimes favored by high temperatures and sometimes not, could lead to a reconfiguration of ecological interactions and, therefore, could cause changes in the structure and functioning of the entire ecosystem,” warned co-author Marta Coll, a researcher at the ICM-CSIC.



These findings could contribute to the design of more effective conservation and management strategies. In future research, the scientists aim to analyze in more detail the changes at the level of the entire ecosystem that may be caused by rising temperatures in the Arctic, as well as the effects on fisheries management and protection measures such changes may cause.



The study is published in the journal <a href="http://dx.doi.org/10.1073/pnas.2120869120">Proceedings of the National Academy of Sciences</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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Arctic biodiversity will get a boost from rising temperatures

A new study led by&nbsp;the&nbsp;Nord University in Norway in collaboration...

<a href="https://www.earth.com/news/oxytocin-promotes-cooperation-among-humans/">Oxytocin</a> – the so-called “love hormone” – has been considered for decades to be essential for the development of social attachments in a variety of animal species. However, according to a new genetic study led by the <a href="https://www.ucsf.edu/">University of California, San Francisco</a> (UCSF) and <a href="https://www.stanford.edu/">Stanford University</a>, prairie voles can still form enduring attachments with their mates and provide parental care even without oxytocin receptor signaling.&nbsp;



Prairie voles are one of the few monogamous mammalian species, forming life-long partnerships called “pair-bonds.” Pair-bonded voles share parental responsibilities, and prefer the company of their partners over other members of the opposite sex, actively rejecting potential new partners. Previous research which used drugs to block oxytocin from binding to its receptor found that voles lacking oxytocin binding were unable to pair-bond.



However, by using a groundbreaking genetic manipulation technique called CRISPR to generate prairie voles lacking oxytocin receptor signaling, the researchers found that these genetically-altered voles could still form pair-bonds just as easily as normal voles.



“We were all shocked that no matter how many different ways we tried to test this, the voles demonstrated a very robust social attachment with their sexual partner, as strong as their normal counterparts,” said study lead author Devanand Manoli, a neuroscientist at UCSF.



Following this surprising discovery, the experts investigated whether oxytocin receptor signaling is similarly dispensable for other functions, such as parturition, parenting, and milk release during lactation. “We found that mutant voles are not only able to give birth, but actually nurse,” reported co-author Nirao Shah, a neuroscientist at Stanford. In fact, both male and female mutants engaged in usual parental behavior, such as huddling, licking, or grooming, and were capable of rearing their offspring to weaning age.



However, the mutant voles had limited milk release compared to the normal ones, which caused fewer of their pups to survive to weaning age. In addition, the pups that managed to survive were smaller compared those of normal voles. The fact that voles could nurse at all is highly different from what has been observed in studies involving oxytocin-deficient mice. According to the researchers, this could be due to the inbred nature of lab mice strains in contrast to the genetically heterogenous voles.&nbsp;



“It could be that inbreeding in mice has selected for a large dependence on oxytocin signaling, or this may represent a species-specific role of oxytocin receptor signaling,”&nbsp;Shah explained.



“For at least the last ten years people have been hoping for the possibility of oxytocin as a powerful therapeutic for helping people with social cognitive impairments due to conditions ranging from autism to schizophrenia. This research shows that there likely isn’t a magic bullet for something as complex and nuanced as social behavior,” Manoli concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.neuron.2022.12.011">Neuron</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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Prairie voles can form close bonds without oxytocin

Oxytocin – the so-called “love hormone” – has been considered...

A new study led by the <a href="https://www.uq.edu.au/">University of Queensland</a> has revealed that some of Asia’s largest animals are thriving near humans. The experts say that <a href="https://www.earth.com/news/tigers-are-threatened-by-road-and-railway-development/">tigers</a>, elephants, and other animals are essentially defying 12,000 years of extinction trends.



Based on paleontological records, the researchers established the historic distribution of Asia’s 14 largest species. The experts compared this data with the present-day distribution of the same species in tropical forests.



According to study lead author and PhD student Zachary Amir, four species showed increased populations in areas with human infrastructure, including tigers, Asian elephants, wild boars, and clouded leopards.



“These results show that, under the right conditions, some large animals can live nearby humans and avoid extinction,” said Amir. “These results challenge the narrative within some conservation circles that humans and megafauna are incompatible."



“Globally there is a trend towards ‘trophic downgrading,' a term referring to the disproportionate loss of the world’s largest animals. Trophic downgrading is usually worst near humans because hunters target larger species."



“But in the case of tigers, elephants, wild boars and clouded leopards, their Asian populations are higher near humans. This may be the outcome of tougher anti-poaching efforts in the national parks that are closer to human settlements and are more frequently visited by tourists.”



On the other hand, the results showed that deforestation is still impacting species - with clouded leopards taking the hardest hit in deforested areas.&nbsp;



Even still, Amir said the research suggests that if the large animal species were not hunted, they could live in relatively small habitats and near humans.



“Previously, there have only been a few examples of large Asian species thriving in small habitats near humans, notably in Mumbai, India where leopards in an urban park prey on stray dogs,” said Amir. “Thankfully, we found that a wider range of animals can coexist with humans.”



At one particular study site in Singapore, poaching has been eliminated and forest restoration efforts are underway. Here, the researchers found that two large animal species are thriving again.



“Singapore has actually experienced the natural re-wilding of sambar deer and wild boars, which are now frequently observed in an urban forest, the Bukit Timah Nature Reserve,” said Amir. “If we replicate those protection efforts in larger forests and other counties, we may see positive impacts right around the world. But before this can happen, humans need to get our act together and limit poaching.”



The study is published in the journal <a href="http://dx.doi.org/10.1126/sciadv.abq2307">Science Advances</a>.



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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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Large Asian animals are successfully coexisting with humans

A new study led by the University of Queensland has...

Scientists have long argued that self-awareness is a rare phenomenon in the animal kingdom, with only a few mammals, some birds, and some fish appearing to have it. However, according to a new study published on the <a href="https://www.biorxiv.org/content/10.1101/2022.11.04.515260v1.full">bioRxiv</a> preprint server, some species of wild penguins, such as the <a href="https://www.earth.com/news/adelie-penguins-antarctica/">Adélie penguins</a> from Antarctica, may also have a certain degree of self-awareness.



While in humans, self-awareness is an easy thing to test, in animals it is much more complicated to reliably assess this capacity. Most studies aiming to test the presence of self-awareness in animals have used the so-called “mirror test,” in which animals are allowed to see themselves in a mirror while scientists observe their reactions. For instance, if animals touch a red mark on their own face that they can only see in the mirror, experts usually assume they have a degree of self-awareness.



In the new study, the researchers traveled to Svenner Island in eastern Antarctica to observe the behavior of Adélie penguins, and conducted four experiments. In the first one, they placed several mirrors on the ground nearby the penguins and observed the animals’ behaviors while looking down at the mirrors. The second experiment involved constructing a cardboard corral around some of the penguins which directed them toward mirrors at the ends of an enclosure, while the third involved placing small stickers on the mirrors that, when viewed, appeared as if they were on the penguins looking at them. In a final experiment, they placed a bib on random penguins in front of a mirror and observed their reactions.



In the first experiments, the scientists detected no response, which was actually an important finding, since many animals fail such a test, believing that the creatures they are seeing in the mirror are actually conspecifics and respond accordingly. While in the second experiment, the penguins moved in ways that suggested they might be examining themselves, in the third one, they became agitated when looking at mirrors with stickers on them and actively tried to remove the stickers. However, they did not respond at all when seeing themselves wearing a bib. Although the results remain rather ambiguous, the researchers argued that they may suggest the presence of at least some degree of self-awareness in penguins.



“Future studies, integrating the socioecology and cognitive ethology of penguins, may provide insights into whether our experimental paradigms could provide evidence to confirm the presence of self-awareness and even of self-recognition in this species and examine whether the observed social awareness may have evolved due to the social needs of individual penguins to engage in cooperative behavior with conspecific individuals, while maintaining their independent decision-making capacities, throughout their communal lives,” the authors concluded. 



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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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Penguins may have a degree of self-awareness

Scientists have long argued that self-awareness is a rare phenomenon...

The Eocene Period (cc. 43 to 66 million years ago) was a time of intense global warming, providing an important case study of how ecosystems react to changing climates. By examining fossils from the Ellesmere Island in Canada, a team of researchers led by the <a href="https://ku.edu/">University of Kansas</a> has found evidence of a warm, swamp-like environment around 52 million years ago, despite half the year experiencing Arctic harsh winter darkness. Based on fossil fragments of jaws and teeth, the experts identified two new species of <a href="https://www.earth.com/news/primates-have-greater-diversity-on-indigenous-lands/">primates</a> - Ignacius dawsonae&nbsp;and&nbsp;Ignacius mckennai - that are our first known relatives from this ancient Arctic ecosystem.



Compared to primate species discovered in more southern regions, both of these species were unusually large (a common trait in northern mammals), and exhibited dental features suggesting a diet of hard food items, which was probably an adaptation for consuming tougher foods during long and dark Arctic winters in which softer meals were hard to find.



Although, during the early Eocene, North America’s lower latitudes were home to many other species of primates, only these two species were discovered in the North, adding to previous evidence that the ancient Arctic ecosystem experienced limited biodiversity compared to southern habitats. According to the researchers, while warmer temperatures allowed several organisms to migrate northward, these movements were most likely limited by factors such as the harsh Arctic winters they had to face once they reached those areas.



These findings could help scientists predict how ecosystems might react to contemporary climate change. “Global warming is transforming Arctic ecosystems in ways that are difficult to predict, but ancient episodes of global warming show how future changes in the Arctic might unfold. The first primate-like fossils ever recovered north of Arctic Circle show that these tropically adapted mammals were able to colonize the Arctic during an ancient episode of global warming approximately 52 million years ago by adopting a new diet of nuts and seeds that enabled them to survive six months of winter darkness,” the authors concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1371/journal.pone.0280114">PLoS ONE</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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Mysterious primates lived in the Arctic 52 million years ago

The Eocene Period (cc. 43 to 66 million years ago)...

Wild <a href="https://www.earth.com/news/most-people-think-insects-will-become-a-sustainable-food-source/">insect</a> pollinators are critical to the formation of seeds and fruit in around 90 percent of flowering plant species, and 75 percent of crop species. Although bees are the best-documented of the insect pollinators, there are many other groups of insects that are also involved. These include flies, beetles, moths, butterflies, wasps and ants. The populations of these crucial organisms are in decline worldwide, mostly due to the activities of humans.&nbsp;



In response to this situation, the Swedish Society for Nature Conservation launched a campaign to encourage the public to create more favorable conditions for pollinators in their private gardens. The project, known as “Operation: Rädda bina” (“Operation: Save the bees”), ran between 2018 and 2021, and around 11,000 Swedes responded initially to the appeal. Researchers from <a href="https://www.lunduniversity.lu.se/">Lund University</a> have now evaluated the success of the measures undertaken by the citizen scientists in their own gardens.



People who responded to the campaign were asked to register pollinator-friendly interventions that they had carried out in their gardens and other green spaces. The campaign encouraged three different interventions: (i) establishing a flowering “garden meadow,” (ii) planting bee-friendly flowers in a garden, and (iii) setting up bee hotels. Those who registered an intervention then completed online questionnaires about their intervention and their perception of any changes in pollinator populations in their garden.&nbsp;



“We wanted to investigate measures that the public themselves chose to implement in their garden, and how these can be the most efficient," said study co-author Anna Persson.



Of the initial respondents, just over 3,200 completed the project. Of these, 809 established flowering meadows, 1,232 planted bee-friendly flowers in their gardens, and 1,210 established a bee hotel. Approximately 19 percent of meadows, 23 percent of plantings, and 20 percent of the bee hotels were situated in the 10 most populated cities/municipalities in Sweden.



When the citizen scientists had to assess the prevalence of pollinators in their gardens, after establishing their intervention, they were asked whether they saw “many,” “few,”,or “no” insects. Because this was rather a simple and subjective metric, the researchers also asked the respondents to count the exact number of pollinators they saw in the garden in a 10-minute period on a sunny day in July. This data was used to confirm the accuracy of the simpler abundance categories, namely many, few or none.&nbsp;&nbsp;



The results, published in the journal <a href="http://dx.doi.org/10.3389/frsc.2022.1099100">Frontiers in Sustainable Cities</a>, indicate that pollinators benefited most where flowering meadows were allowed to grow. This could be where a person decided not to mow a patch of grassland and let it rather grow tall with wild flowers, or where a meadow stood unused and untouched for several years. In both instances, the benefit was greater if the meadow was older and if there was a diversity of flowering species present.



People who planted bee-friendly flowers in their garden found the benefit for pollinators was greatest when the flowering plants were older and covered a large area. This is important, because people who initially record no benefit from their newly-planted flowers should not give up, but should continue with the knowledge that older, more established flower beds will bring the pollinators in time.&nbsp;



Bee hotels, in turn, tended to attract more inhabitants if they were located in flower-rich gardens, if they were older, and if the nest holes were no larger than one centimeter in diameter.



Anna Persson believes the results of the study are helpful when giving guidance to those who want to make their gardens attractive for pollinators.



“For example, we can show that it will pay off to create large and species-rich meadows and flower plantings, and that it is important not to give up after a few years, because the measures improve over time. This should be emphasized in future campaigns."



Persson also hopes that the results can inspire more people to adapt their own green space so that it becomes more favorable for insects. Gardens often cover about 30 percent of the land area in cities and towns, so garden owners, as a group, have the potential to contribute considerably to urban biodiversity.



The accuracy of citizen scientist accounts can sometimes be questioned, because the participants may have certain expectations about the results they will see.&nbsp;



“Our study could be affected by so-called ‘expectation bias,'" said Persson. “This means that people who have taken measures and created more species-rich gardens also expect to see more insects, and thus risk reporting too high a number.”



However, the researchers found that the actual counts of insects correlated well with what participants categorized as “many” or “few” insects. A total of 350 participants counted the insects they saw in their garden in a 10-minute period, and their responses helped to verify the accuracy of the dataset.



This study is particularly relevant since a third of Sweden’s bee species are currently considered to be endangered. The results show that steps taken by individual homeowners to make conditions in the garden more favorable to pollinators really do make a difference. This is encouraging, as pollinators are critical for functioning ecosystems and need all the help they can get at this stage.



“The situation for bees and other pollinators shows that measures to help them are important," said Karin Lexén, Secretary General of the Swedish Society for Nature Conservation. "It’s great that the campaign has attracted so much attention, and that citizen science can continue to contribute to new knowledge."



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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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Gardeners can make small changes to benefit pollinators

Wild insect pollinators are critical to the formation of seeds...

Episiphon filum

Taxonomic tree: