//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Step-by-step – Not much can mess with a lion. They’re four-hundred-pound top predators, bringing down large prey like wildebeests, zebras, and even giraffes. But they’re not invincible — a new study delves into the interactions between lions and porcupines, and shows how these spiky, cocker spaniel-sized critters can come out on top. “By examining records of lions that have been injured by porcupines, we were able to develop a better picture of the conditions that lead lions to try to hunt porcupines and what happens to the lions who get stuck,” says Julian Kerbis Peterhans, a researcher at the Field Museum, professor at Roosevelt University, and lead author of the new study in the Journal of East African Natural History. “It’s David and Goliath on the African savanna. The powerful king of the savanna tries to eat a juicy, fat porcupine, but he gets hurt by the quills,” says co-author Gastone Celesia, a volunteer at the Field and professor emeritus of neurology at Loyola University Chicago. “Even though lions are at the top of the food chain, they get injured if they don’t watch what they’re doing.” African porcupines are large rodents, weighing about about forty pounds, and predators (including humans) seek them out for their tasty meat. But their backs are covered in sharp quills made of keratin, the same material as hair and fingernails. These quills, which can be a foot long or more, can detach and get stuck in the flesh of predators careless or desperate enough to attack the porcupines. There are stories and records of lions getting injured by porcupines going back hundreds of years — in June, July, and August of 1656,an official from the Dutch East Company in Cape Town wrote in his diary about three different lions that had been stuck with porcupine quills. In many of these cases, the lions’ injuries made it harder for them to hunt or eat. They sometimes turned to easier prey, like cattle or even humans. However, prior to this study, no one had carefully compiled all the records of lions injured by porcupines to better understand the two species’ relationship. The team scoured scientific literature, stories in the popular press, and even YouTube videos looking for evidence of lion-porcupine interactions. “I think that digging deeply into the historic literature, especially very early sources, has largely fallen out of fashion in the modern era,” says Tom Gnoske, a co-author of the paper and an assistant collections manager at the Field Museum. “There are treasures still to be found, but going back in the written record four centuries, well, that takes some patience and time.” The team found evidence of about fifty lions that had been injured or killed by porcupines. Several trends appeared to emerge from the data. Lions that lived on harsher, drier terrain seemed to rely more on porcupines for food, at least periodically, perhaps because other prey weren’t available. Young lions were more likely to try to hunt porcupines than older lions. And most of the lions injured by porcupines were male. “There was a tendency for males to be more often wounded or killed by porcupines — sort of a ‘young foolish male syndrome,’” says Kerbis Peterhans. To compound matters, young males aren’t just taking part in risky behavior, but when they so alone, without other lions to help them if they do get hurt, they are more vulnerable. “In social contexts, a lion can remove porcupine quills with the help of a friend, but this is not possible if they are solitary,” he explains. In addition to piecing together clues about what drives lions to hunt porcupines despite the risk the rodents pose, the researchers were able to use CT scans to more closely examine the effects that porcupine quills have had on lion specimens. The team scanned the skulls of two man-eating lions from 1965. One had been stuck through the nose with a nine-inch quill, and the other had an inch-long segment of a quill embedded in the nerve pulp of its broken canine tooth. “We were like detectives,” says Celesia of the forensic work the team did to better understand the injuries that the lions sustained and figure out what the effects on the lions’ hunting abilities would be. “CT scans let us reconstruct what happened in the past.” The scans showed evidence of bone infections that would have impaired both of these lions’ ability to eat (or, in the case of the lion with a quill through its nose, to smell its prey) — factors that could have contributed to man-eating. Generally speaking, lions attack humans if something’s wrong, like if they’re not physically able to take down their usual prey or if they don’t have enough space or resources to hunt normally. Kerbis Peterhans notes the importance of the study in better understanding a condition that leads lions to harm people. “Porcupine injuries are an anticipator of attacks on humans, there’s a potential impact on human beings,” he says. And the study has broader ecological significance, too. “We know from forty-plus years of continuous behavioral research on lions since the 1960s that lions prefer large hooved animals as prey, including antelope, zebra, and buffalo,” says Gnoske. “And our data suggest that by the time the lions are relegated to eating porcupines, there’s already a problem with the local food supply. Historic records tell us that when environmental conditions deteriorate, particularly in areas where lions and their preferred prey are already living on the edge, they find themselves in serious trouble with nearby humans or their livestock.” “One moral of the story is that there no free lunch,” says Celesia. “Even the king of beasts doesn’t eat what he wants without paying a price.” //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Get Closer To Your Pet via Secret Of Pet Secret Of Pet All Goods For Our Friends
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Work quickly: A genomic tour-de-force reveals the last 5000 years of horse history ScienceDaily5/27/2019 //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Work quickly – Each year on the first Saturday in May, Thoroughbred horses reach speeds of over 40 miles per hour as they compete to win the Kentucky Derby. But the domestic horse wasn’t always bred for speed. In fact, an international team now has evidence to suggest that the modern horse is genetically quite different from the horses of even just a few hundred years ago. Their work, appearing May 2 in the journal Cell, constructs the genetic history of the domestic horse across the world over the last 5,000 years by using the largest genome collection ever generated for a non-human organism. The findings identify two new horse lineages that are now extinct and suggest that familiar traits such as speed were only selected for more recently in their history. “The horse has impacted human history like no other animal,” says Ludovic Orlando, a research director with CNRS and the University of Toulouse and a Professor of Molecular Archaeology at the University of Copenhagen. “If you look at the historical record from the Bronze Age onward, horses are always part of the equation up until very recent times, connecting civilizations and impacting transportation, warfare, and agriculture. Our goal was to understand how humans and their activities transformed the horse throughout history to fit their purposes — and how these changes in biology influenced human history.” The team responsible for this project consisted of 121 collaborators, including geneticists, archaeologists, and evolutionary biologists from 85 institutions around the world, and examined genome-scale data from 278 horse specimens from across Eurasia over the last 42,000 years. “Such a large collection of data means that we can build a much more precise understanding of horse domestication and management through space and time,” Orlando says. “But it was truly an interdisciplinary effort because of course it takes a lot more than just DNA to understand such a story. We had to integrate all these social, historical, and geographical aspects.” Overall, the team’s findings suggest that equine history was much more complex than was previously realized. Today, there are only two known lineages of horses, the domestic horse and the Przewalski’s horse. But the researchers here identified two additional now-extinct lineages of horses, one from the Iberian Peninsula and one from Siberia, both of which still existed 4,000-4,500 years ago. “We found two lineages of horses at the far ends of Eurasia that are not related to what we call the domestic horse today, nor to the Przewalski’s horse. They are a sort of horse equivalent of what Neanderthals are to modern humans,” Orlando says. The researchers also found a major shift in the genetic makeup of horses in Europe and Central Asia in the 7th to 9th centuries and say this shift probably corresponds to Islamic expansions. The horses common in Europe before that time are now only found in regions such as Iceland; the new European horses after that time were much more similar to horses found in Persia during the Sassanid Empire. When the team performed a scan to identify genes that had been selected for in these Persian horses, they found evidence of selection in genes associated with body shape. “It was a moment in history that reshaped the landscape of horses in Europe. If you look at what we today call Arabian horses, you know that they have a different shape — and we know how popular this anatomy has been throughout history, including in racing horses. Based on the genomic evidence, we propose that this horse was so successful and influential because it brought a new anatomy and perhaps other favorable traits,” he says. The researchers found that there have been additional significant and recent changes in the domestic horse. Similar selection scans indicate that only in the last 1,500 years did traits such as ambling and speed over short distances become more actively sought. And when they looked at the overall genetic diversity of the domestic horse, the researchers found a sharp decline in the last 200 to 300 years. They believe this decline corresponds with new breeding practices that were introduced with the rise of the concept of “pure” breeds. “What we picture as a horse today and what we picture as a horse from a thousand years ago or two thousand years ago was likely actually very different. Some of those traits that we are most familiar with are only a modern invention, and in the last few hundred years, we have actually impacted the horse genome a lot more than in the previous 4,000 years of domestication,” says Orlando. He believes that this research can tell us a lot about both the past and the present. “Our findings show that the past is a lot more diverse than we thought it was and that it cannot be imagined or inferred through modern-day variation. But ancient DNA tells us a lot about today as well, because it teaches us about the consequences of some shifts in breeding practices,” he says. And that, he believes, can also affect the way we think about conservation and modern agricultural practices. Of course, our understanding of the domestic horse’s history is far from complete. Orlando acknowledges that there are geographic and temporal gaps in his story. Perhaps mostly glaringly, we still don’t know when and or where the horse was domesticated. “Horse domestication is central to human history, and in 2019, we still don’t understand where it started. That’s mind-blowing,” he says. He looks forward to filling in those blanks. “Whenever I’m asked about what finding I’m most excited about, I always say, the next one. Because this research opens the door for so many possibilities to be studied now.” Story Source: Materials provided by Cell Press. 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via Secret Of Pet Secret Of Pet All Goods For Our Friends Step-by-step: First comprehensive study in Mexicali Mexico looks at disease spread ScienceDaily5/27/2019 //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Work quickly – In Mexicali, Mexico, an uncontrolled epidemic of Rocky Mountain spotted fever, one of the deadliest tickborne diseases in the Americas, has affected more than 1,000 people since 2008. A binational team of researchers led by the University of California, Davis, has conducted the first comprehensive study to examine risk factors for the disease in Mexicali. Researchers examined dogs, ticks, and surveyed households in 200 neighborhoods. Half of the neighborhoods in the study had diagnosed human cases of the disease. They discovered that, even though citywide only one in 1,000 ticks was infected, there were neighborhoods at very high risk, where almost one in 10 ticks were infected. “If you live in one of these high-risk neighborhoods and you get five brown dog tick bites, that means you have a pretty good chance of being exposed to Rocky Mountain spotted fever,” said lead author Janet Foley, with the Department of Medicine and Epidemiology at the UC Davis School of Veterinary Medicine. Rocky Mountain spotted fever is spread by the brown dog tick, which feeds on dogs and people, and thrives in hot, arid climates. Previous studies have shown that poverty, numerous stray dogs and brown dog ticks increased the risk of getting Rocky Mountain spotted fever. In Mexicali, risks were higher along the edges of poorer neighborhoods or outside of the city in rural areas. Half of the 284 dogs the researchers examined were infested with ticks. Some dogs carried thousands of ticks. “Almost three-quarters of the dogs we tested had been infected with the agent of Rocky Mountain spotted fever at some point in their life,” said Foley. “That’s astronomical.” A Deadly Disease People with Rocky Mountain spotted fever typically develop symptoms one to two weeks after being bitten by an infected tick. They can develop fever, nausea, headache and muscle pain. As the bacteria infect blood vessel linings, blood begins to pool under the skin, resulting in a rash that can look like red splotches or spots. The longer people wait before seeing a doctor and starting treatment with antibiotics, the greater chance they may die. The study, published in the American Journal of Tropical Medicine and Hygiene, also gauged people’s knowledge about Rocky Mountain spotted fever. It found 80 percent of residents had heard of the disease, but fewer than half used pesticides to prevent bites. Ticks Could Spread North with Climate Change Foley said a Rocky Mountain spotted fever epidemic on the scale of that in Mexicali is not as likely in the United States as long as dog ticks are well managed. But as temperatures warm with climate change, there are concerns that the particular human-feeding brown dog tick strain will continue to move north, resulting in more human cases. Some studies have suggested the hotter it gets, the more active and aggressive the ticks become. Other authors include Emily Pascoe of UC Davis. The binational team included academic researchers, health workers, epidemiologists, veterinarians, agency officials, medical doctors and students, which aided in the need to communicate in Spanish and English, address canine and human disease, understand fundamental epidemiological patterns, and protect public health. The study was funded by the U.S. Centers for Disease Control and Prevention, the UC Davis School of Veterinary Medicine and by the Autonomous University of Baja California. Story Source: Materials provided by University of California – Davis. Original written by Amy Quinton. Note: Content may be edited for style and length. //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Subscribe
via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); best – Understanding how people use and experience important places for living nature is essential for effectively managing and monitoring human activities and conserving biodiversity. In a new article published in the journal Science of the Total Environment, a team of researchers assessed global patterns of visitation rates, attractiveness and pressure to more than 12,000 Important Bird and Biodiversity Areas (IBAs), which are sites of international significance for nature conservation, by using geolocated data mined from social media (Twitter and Flickr). The study found that Important Bird and Biodiversity Areas located in Europe and Asia, and in temperate biomes, had the highest density of social media users. Results also showed that sites of importance for congregatory species, which were also more accessible, more densely populated and provided more tourism facilities, received higher visitation than did sites richer in bird species. “Resources in biodiversity conservation are woefully inadequate and novel data sources from social media provide openly available user-generated information about human-nature interactions, at an unprecedented spatio-temporal scale,” says Dr Anna Hausmann from the University of Helsinki, a conservation scientist leading the study. “Our group has been exploring and validating data retrieved from social media to understand people´s preferences for experiencing nature in national parks at a local, national and continental scale,” she continues, “in this study, we expand our analyses at a global level.” Tourism is one of the fastest growing industries worldwide, and conservation areas are becoming popular destinations for people seeking nature-based experiences. “Important Bird and Biodiversity Areas represent some of the most important places for nature across the planet. Our results now allow us to pinpoint which of these sites face potentially the greatest threats or greatest opportunities resulting from high numbers of visitors.” says Dr Stuart Butchart, Chief Scientist at BirdLife International, who co-authored the study. “Social media content and metadata contain useful information for understanding human-nature interactions in space and time,” says Prof. Tuuli Toivonen, another co-author in the paper and the leader of the Digital Geography Lab at the University of Helsinki. “Social media data can also be used to cross-validate and enrich data collected by conservation organizations,” she continues. The study found that the 17 percent of all Important Bird and Biodiversity Areas (IBA) that were assessed by experts to be under greater human disturbance also had higher density of social media users. Therefore, these sites should be priority for management actions aimed at minimizing pressure at sites. “However, data on threats do not yet exist for many highly visited Important Bird and Biodiversity Areas, even in North America and Europe. Mobilizing such data worldwide should be priority,” says Dr Thomas Brooks, Chief Scientist of IUCN, who also co-authored the paper. “With the increasing use of social media worldwide, automatic content analysis of digital data sources will help us understand present or emerging human-related threats at sites where threats are currently unknown or difficult to assess,” says Adjunct professor Enrico Di Minin, senior co-author who leads the Helsinki Lab of Interdisciplinary Conservation Science at the University of Helsinki. “We are currently applying and developing machine learning and natural language processing methods to analyze large amount of online information, in order to understand human-nature interactions and inform conservation science and practice,” he concludes. Story Source: Materials provided by University of Helsinki. Original written by Riitta-Leena Inki. Note: Content may be edited for style and length. //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Subscribe via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Right now – Can the environment affect how the spinal cord develops specialized circuitry, or is that process hardwired, following prescribed genetic instructions turned on early in the embryo? A UC Davis study that compared the effects of cold and warm temperatures on the development of frog eggs into larvae found that environmental temperature significantly changes how the nervous system develops. The study, which appears online May 23 in the journal Current Biology, found environmental temperature activated temperature-sensitive channels, influencing gene expression and altering neurodevelopment. The research, while conducted in frogs, has parallels across species, including humans. “We found that the temperature-sensitive channel TRPM8 drives changes in the developing nervous system, allowing frogs to adapt to the environment,” said Laura Borodinsky, professor of physiology and membrane biology at UC Davis School of Medicine and study senior author. “Larvae grown in cold temperatures had more neurons responsible for movement — a crucial function that better equips young frogs to escape predators and other potential dangers,” she said. “They also had larger muscle mass and a stronger swim response than those reared in warmer temperatures when tested at cold temperatures.” Temperature important for neurodevelopment in humans Temperature is an important factor in the development of the nervous system in humans. Newborns, especially premature babies, do not develop the ability to regulate body temperature until a few months after birth or even longer. Studies also suggest that fever during pregnancy may affect the developing brain and nervous system, increasing the risk of autism spectrum disorder and schizophrenia. Borodinsky believes when temperature changes are sudden and occur during critical periods of development — or when molecular mechanisms to adapt to these changes are not working — disruptions in nervous system development can affect health. Temperature channels as a way the environment changes gene expression Temperature-sensitive channels belong to a diverse family of ion channels, TRP channels, that respond to a range of conditions. While some TRP channels are temperature sensors, others are sensitive to pain, pH, touch, light and sound. These cellular pathways that allow organisms to sense temperature are well-conserved through evolution and present across species. For the study, Kira A. Spencer, first author of the paper and a former graduate student in the Neuroscience Graduate program at UC Davis, raised fertilized frog eggs at cold or warm temperatures in Petri dishes. At the larval stage, they measured responses to light touch and swimming responses, and number of spinal motor neurons. They assessed the dependence of spontaneous electrical activity, which drives many aspects of neuronal differentiation, on temperature, as well as the genetic factors that regulate developing spinal cord cells and the role of the cold-temperature channel TRPM8. “We found that the cold-temperature sensitive channel TRPM8 mediates the developmental changes that give frog larvae an advantage and allow them to function optimally in cold temperatures,” Spencer said. “Our results provide insight into how the environment influences gene expression during development, and point to a promising avenue for exploring how genes and the environment interact, including the role that other TRP channels play in nervous system development and disease.” Other study authors include Yesser Hadj Belgacem, Olesya Visina, Sangwoo Shim and Henry Genus. The research was supported with from the National Science Foundation (1120796), National Institute of Neurological Disorders and Stroke (RO1NS073055) and Shriners Hospital for Children (86500-NCA, 85220-NCA, 85300-NCA). //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Subscribe To Our Newslatter In The Link Below. via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Simple – When Stephen Pruett-Jones, PhD, an ecologist at the University of Chicago, first came to Chicago in 1988, he stumbled on a unique piece of the city’s history: the monk parakeets of Hyde Park. The squat, bright-green birds aren’t native to Illinois, or the United States at all. The U.S. originally had two native parrot species: the Carolina parakeet and the thick-billed parrot. The Carolina parakeet is now extinct; the thick-billed parrot, a Mexican species that ranged into the southwestern states, was driven out of the U.S. In the 1950s and 60s, tens of thousands of monk parakeets were imported from South America as pets. Inevitably, many of them escaped or were released. By 1968, they were found breeding in the wild across 10 states, including a colony in the Hyde Park neighborhood of Chicago, home of the University of Chicago campus. Pruett-Jones, who usually studies wrens and other wild birds in Australia, noticed a large group of the parakeets on his daily commute. He started sending students out to study the birds and eventually organized an annual lab project to count them. “I have never actually held a wild parrot in the United States,” he said. “But indirectly I’ve become the spokesperson for parrot research here because when I saw the monk parakeets in Chicago, I realized nobody else was working on them.” Those monk parakeets aren’t the only parrot species thriving in the U.S. as a result of the pet trade. In a recent study, Pruett-Jones teamed up with Jennifer Uehling, a former UChicago undergraduate student now working on a PhD at Cornell University, and Jason Tallant of the University of Michigan to research data on bird sightings from 2002 to 2016. They found that there were 56 different parrot species spotted in the wild in 43 states. Of these, 25 species are now breeding in 23 different states. “Many of them were escaped pets, or their owners released them because they couldn’t train them or they made too much noise — all the reasons people let pets go,” Pruett-Jones said. “But many of these species are perfectly happy living here and they’ve established populations. Wild parrots are here to stay.” A diverse new landscape for parrots The study, published in the Journal of Ornithology, uses two different databases of bird sightings to track this diverse new landscape of naturalized parrot species. The first, the Christmas Bird Count, is an annual survey organized by the National Audubon Society that captures a snapshot of birds in the U.S. during a two-week period from December 14 to January 15 each year. The second resource, eBird, is an online database for bird watching enthusiasts to log all the birds they have seen. Once Uehling, Tallant, and Pruett-Jones compiled the data, the most common species were monk parakeets, the Red-crowned Amazon, and the Nanday Parakeet. Most of these birds are concentrated in the warmer climates of Florida, Texas and California, but there are other large populations concentrated around cities like New York and Chicago. Pruett-Jones says there are now more Red-crowned Amazons living in California than there are in their original habitats in Mexico. “The entire conservation focus for this species is now on a non-native, introduced, naturalized population,” he said. “The survival of the species is most likely going to come from efforts to save it someplace where it never existed before.” Monk parakeets are reported to be agricultural pests in South America, but other than a few isolated examples, there is no evidence that any of the feral parrots in the U.S. are invasive or competing with native birds. Monk parakeets are the only species of parrot that build their own nests, however, and the bulky structures are known to damage utility lines. Good luck talisman The story of Chicago’s parakeets is one with the city, that of tenacious survival in spite of the elements. Most of the year they feed by foraging in parks and open grassy areas. They don’t migrate, but one of Pruett-Jones’ students discovered that they survive Chicago’s harsh winters by switching almost exclusively to backyard bird feeders from December to February. Harold Washington, Chicago’s first African American mayor, lived across the street from one of the city’s best-known parakeet colonies and called them a “good luck talisman.” After he died in 1987, the USDA tried to remove the birds, but local residents threatened a lawsuit. The parakeets stayed but their numbers have dwindled from a peak of about 400 birds to just 30 today. Some of the them have dispersed to greener areas in the suburbs, although the largest colony is now under the Skyway bridge connecting Illinois to Indiana. There are also signs of a nationwide decline in all birds, perhaps due to a disease or parasite. Pruett-Jones may have become a national expert on parrots by accident, but he says this work is crucial to understand conservation of endangered species and how non-native or invasive species can spread. “Because of human activity transporting these birds for our own pleasure, we have inadvertently created populations elsewhere,” he said. “Now for some of these parrots, they may become critical to the survival of the species.” //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Subscribe
via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); best – Tiger sharks have a reputation for being the “garbage cans of the sea” — they’ll eat just about anything, from dolphins and sea turtles to rubber tires. But before these top predators grow to their adult size of 15 feet, young tiger sharks have an even more unusual diet. Scientists have just announced in a new paper in Ecology that baby tiger sharks eat birds. And not seabirds like gulls or pelicans — familiar backyard birds like sparrows, woodpeckers, and doves. “Tiger sharks will see an easy meal and snatch it up, but I was surprised to learn that the sharks were eating songbirds — I assumed that they’d be seabirds,” says Kevin Feldheim, a researcher at Chicago’s Field Museum and a co-author of the study who led the DNA analysis that told the researchers what kinds of birds the sharks were eating. “It was one of the coolest projects I’ve been associated with using DNA to tell a story.” The paper’s lead author, Marcus Drymon of Mississippi State University, and his team investigated juvenile tiger sharks’ diets by wrassling the three-foot-long sharks onto a boat, pumping the sharks’ stomachs, and analyzing a sample of their stomach contents. (The sharks were then released unharmed.) Drymon and the team were surprised to see that of the 105 sharks they studied, 41 had bird remains in their stomachs. But since the birds were partially digested, it was hard for the scientists to tell exactly what kinds of birds they were. To figure it out, they sent the bird remains to the Field Museum’s Pritzker Laboratory for Molecular Systematics and Evolution for DNA analysis. The scientists took tiny pieces of the bird remains and used chemicals to break them down into their basic molecular components. From there, they were able to examine the DNA sequences present in the bird tissues and compared them to databases of bird DNA to see what species they were from. “None of them were seagulls, pelicans, cormorants, or any kind of marine bird,” Drymon says. “They were all terrestrial birds” — the kinds that might live in your backyard. This isn’t the first time that tiger sharks have been known to eat birds. “There’s a site off Hawaii where baby albatrosses learn to fly, and adult tiger sharks pick them off,” explains Feldheim. But this is the first time scientists have evidence that tiger sharks eat songbirds that primarily live on land. That’s because these sharks were in the Gulf of Mexico, during migration season. “In every instance, the timing of the tiger shark eating the bird coincided with the peak sighting for that species of bird off our coast,” says Drymon. “The tiger sharks scavenge on songbirds that have trouble flying over the ocean. During migration, they’re already worn out, and then they get tired or fall into the ocean during a storm,” adds Feldheim. He notes that the terrestrial birds might make more attractive prey than seabirds because the seabirds can handle themselves better in and around the water than the songbirds can. The study gives scientists a better understanding of tiger sharks, which could ultimately help us to protect them. “All sharks are in trouble,” says Feldheim. “We don’t know the extent of how industrialized fishing has taken a toll, but the vast majority of top predator populations have declined in recent years.” Beyond the conservation implications, though, Feldheim argues that the study shows the importance of having DNA databases available to scientists: “It shows us how much more we can still learn about sharks in general and what DNA can tell us that observation can’t.” This study was contributed to by scientists from Mississippi State University Extension Service, Mississippi-Alabama Sea Grant, Field Museum, Forbes Biological Station-Bellrose Waterfowl Research Center, the National Oceanic and Atmospheric Administration National Marine Fisheries Service, and the University of South Alabama. Story Source: Materials provided by Field Museum. Note: Content may be edited for style and length. //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Get Our Newslatter Straight To Your Inbox via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Step-by-step – Bedbugs — some of the most unwanted human bed-mates — have been parasitic companions with other species aside from humans for more than 100 million years, walking the earth at the same time as dinosaurs. Work by an international team of scientists, including the University of Sheffield, compared the DNA of dozens of bedbug species in order to understand the evolutionary relationships within the group as well as their relationship with humans. The team discovered that bedbugs are older than bats — a mammal that people had previously believed to be their first host 50-60 million years ago. Bedbugs in fact evolved around 50 million years earlier. Bedbugs rank high among the list of most unwanted human bedfellows but until now, little was known about when they first originated. Experts have now discovered that the evolutionary history of bed bugs is far more complex than previously thought and the critters were actually in existence during the time of dinosaurs. More research is needed to find out what their host was at that time, although current understanding suggests it’s unlikely they fed on the blood of dinosaurs. This is because bed bugs and all their relatives feed on animals that have a “home” — such as a bird’s nest, an owl’s burrow, a bat’s roost or a human’s bed — a mode of life that dinosaurs don’t seem to have adopted. The team spent 15 years collecting samples from wild sites and museums around the world, dodging bats and buffaloes in African caves infected with Ebola and climbing cliffs to collect from bird nests in South East Asia. Professor Mike Siva-Jothy from the University of Sheffield’s Department of Animal and Plant Sciences, who was part of the team, said: “To think that the pests that live in our beds today evolved more than 100 million years ago and were walking the earth side by side with dinosaurs, was a revelation. It shows that the evolutionary history of bed bugs is far more complex than we previously thought.” Dr Steffen Roth from the University Museum Bergen in Norway, who led the study, added: “The first big surprise we found was that bedbugs are much older than bats, which everyone assumed to be their first host. It was also unexpected to see that evolutionary older bedbugs were already specialised on a single host type, even though we don’t know what the host was at the time when T. rex walked the earth.” The study also reveals that a new species of bedbug conquers humans about every half a million years: moreover that when bedbugs changed hosts, they didn’t always become specialised on that new host and maintained the ability to jump back to their original host. This demonstrates that while some bedbugs become specialised, some remain generalists, jumping from host to host. Professor Klaus Reinhardt, a bedbug researcher from Dresden University in Germany, who co-led the study, said: “These species are the ones we can reasonably expect to be the next ones drinking our blood, and it may not even take half a million years, given that many more humans, livestock and pets that live on earth now provide lots more opportunities.” The team also found that the two major bedbug pests of humans — the common and the tropical bedbug — are much older than humans. This contrasts with other evidence that the evolution of ancient humans caused the split of other human parasites into new species. Professor Mike Siva-Jothy from the University of Sheffield, added: “These findings will help us better understand how bedbugs evolved the traits that make them effective pests — that will also help us find new ways of controlling them.” The researchers hope the findings will help create an evolutionary history of an important group of insects, allowing us to understand how other insects become carriers of disease, how they evolve to use different hosts and how they develop novel traits. The aim is to help control insects effectively and prevent the transmission of insect-vectored disease. The research has been published in Current Biology. //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Are You Doing Your Pets Wrong?
via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Simple – Scientists know that age and weight are risk factors in the development of cancer. That should mean that whales, which include some of the largest and longest-lived animals on Earth, have an outsized risk of developing cancer. But they don’t. Instead, they are less likely to develop or die of this enigmatic disease. The same is true of elephants and dinosaurs’ living relatives, birds. Marc Tollis, an assistant professor in the School of Informatics, Computing, and Cyber Systems at Northern Arizona University, wants to know why. Tollis led a team of scientists from Arizona State University, the University of Groningen in the Netherlands, the Center for Coastal Studies in Massachusetts and nine other institutions worldwide to study potential cancer suppression mechanisms in cetaceans, the mammalian group that includes whales, dolphins and porpoises. Their findings, which picked apart the genome of the humpback whale, as well as the genomes of nine other cetaceans, in order to determine how their cancer defenses are so effective, were published today in Molecular Biology and Evolution. The study is the first major contribution from the newly formed Arizona Cancer and Evolution Center or ACE, directed by Carlo Maley under an $8.5 million award from the National Cancer Institute. Maley, an evolutionary biologist, is a researcher at ASU’s Biodesign Virginia G. Piper Center for Personalized Diagnostics and professor in the School of Life Sciences. He is a senior co-author of the new study. The study found that nature has beaten cancer in countless ways across the tree of life, Tollis said, and researchers can use that information to help find potential new targets for preventing cancer in humans, like using the whale version of a protein that can stop cell proliferation to develop drugs that shrink tumors in humans. “Our goal is not only to get nature to inform us about better cancer therapies, but to give the public a new perspective of cancer,” Tollis said. “The fact that whales and elephants evolved to beat cancer, and that dinosaurs suffered from it as well, suggests that cancer has been a selective pressure across many millions of years of evolution, and it has always been with us. Our hope is that this may change people’s relationship with the disease, which can be painful and personal. It also helps provide even better appreciation for biodiversity. In our current sixth mass extinction, we need all the reasons for conservation that we can get.” Why whales? At its most basic, cancer occurs when body cells divide and mutate. Cell division is normal in living creatures, as are body cell, or somatic, mutations. Most of the time, somatic mutations are either harmless or the body is able to fix those mutations. When it doesn’t, that can lead to cancer. Beyond that foundation, cancer gets much more complicated. For all of the research being done on all types of cancer and all types of organisms, there are still more questions than answers. However, age and body size are well-known risk factors in people. Tollis said one explanation for this is that cancer risk overall is a function of the number of cell divisions that occur over the lifetime of an organism. “This is driven by somatic evolution — genetic changes that occur when body cells copy their genomes, divide and produce daughter cells,” he said. “The longer you live, the more cell divisions you have and the higher chance that a cancer-causing mutation will occur in the genome of the descendent cells. Similarly, larger individuals are made of more cells, which also increases the chance of cancer-causing mutations.” Knowing this, it’s worth looking at whether whales, which live longer than most mammals on the planet and have a much higher percentage of body fat, are more likely to develop cancer. They aren’t. This phenomenon, known as Peto’s Paradox, is what Tollis and his team studied. How do whales defy these well-known risk factors? In earlier research, ASU’s Carlo Maley investigated alternate mechanisms responsible for cancer suppression in elephants. Methods and conclusions The team worked under a federal research permit to obtain skin samples from an adult female humpback whale off the coast of Massachusetts. This whale, named Salt, is well-known to researchers and whale watchers alike. She was cataloged by the Center for Coastal Studies in the mid-1970s and selected for this study because her life history is among the most well-documented of any individual humpback whale. The team sequenced and assembled Salt’s genome, which requires extracting DNA from skin tissue, fractioning it into smaller bits and put through a DNA sequencer that produces almost 2 billion short sequences. Then they put those sequences back together into a genome assembly that spans about 2.7 billion base pairs. (By contrast, the human genome is about 3.1 billion base pairs long.) They also sequenced RNA, which helps in the process of finding the precise coordinates where genes lie in the genome. The team then compared the humpback whale genome to those of other mammals including other ocean giants like the blue whale, fin whale, bowhead whale and sperm whale. They expected to see a lot of differences, but also a few similarities, particularly with the parts of the genome that perform important functions. They also looked for parts of the genome that had evolved to help whales adapt to their environment. What they found was that some parts of the whale genome have evolved faster than in other mammals. These parts of the whale genome contain genes that control the cell cycle, cell proliferation and DNA repair, which are essential for normal cell function. In human cancers, many of these genes are mutated. The whale genome also evolved many duplications in tumor suppressor genes. “Nature is showing us that these changes to cancer genes are compatible with life. The next questions are, which of these changes is preventing cancer, and can we translate those discoveries into preventing cancer in humans?” said Carlo Maley, a cancer evolutionary biologist from ASU’s Biodesign Institute and one of the two senior authors, who started this project in 2011 with Per Palsbøll, a marine mammal conservation geneticist from the Groningen Institute for Evolutionary Life Sciences at University of Groningen, in collaboration with Jooke Robbins from the Center for Coastal Studies. “This suggests that whales are unique among mammals in that in order to evolve their gigantic sizes, these important ‘housekeeping’ genes, that are evolutionarily conserved and normally prevent cancer, had to keep up in order to maintain the species’ fitness,” Tollis said. “We also found that despite these cancer-related parts of whale genomes evolving faster than other mammals, on average whales have accumulated far fewer DNA mutations in their genomes over time compared to other mammals, which suggests they have slower mutation rates.” This slow rate of change may also limit whales’ exposure to cancer-causing somatic mutations. This study builds on research that the ASU team has done finding lower rates of cancer in elephants, another mammal that is large and can live a long time but doesn’t have much in common genetically with whales. Both species arrived at the same result — cancer suppression — through different mechanisms. The same is likely true of extinct giant dinosaurs; although scientists have found evidence of cancer in dinosaur fossils, this group of organisms includes the largest animals ever to walk the earth and thus they probably had efficient cancer suppression as well. Next steps for Tollis and his team will be to better understand the cancer suppression phenotype using experiments with whale cell lines, which will provide important functional validation of the team’s genomic results. That will be the first step in generating whale-derived human cancer drugs. They also are looking at other animals, such as bats, tortoises and crocodilians, to see how these varied long-lived species suppress cancer. The humpback whale genome also will serve as the basis for studies by other team members on whale mutation rates and other adaptations taking advantage of a collection of the 9,000-plus DNA samples collected from free-ranging humpback whales curated by Palsbøll’s team. This research is supported by the Arizona Cancer Evolution Center, which is funded through a five-year grant from the National Institutes of Health, with additional funding by the University of Groningen. //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Are You Doing Your Pets Wrong?
via Secret Of Pet Secret Of Pet All Goods For Our Friends //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Work quickly – Preventing the introduction of the mosquitofish and removing its population are the most effective actions to control the dispersal of this exotic fish in ponds and lakes, according to a study published in the journal Science of the Total Environment. Neither the presence of predators nor the degradation of the quality of water and natural habitat are a threat to this invasive species — from the Atlantic coast in North America — which competes against and moves local species away. The new study, carried out in water ecosystems close to urban environments of the Barcelona provincial area, is signed by the experts Oriol Cano Rocabayera, Adolfo de Sostoa, Lluís Coll and Alberto Maceda, from the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio). An exotic species threatening local fish The mosquitofish (Gambusia holbrooki) is an edacious exotic fish regarded as one of the most dangerous invasive species at a global scale according to the International Union for the Conservation of Nature (UICN). It was brought to Spain in 1921 for the biological control of mosquitoes — carrying diseases such as malaria — and is now included in the catalogues of exotic invasive species of the Ministry of Agriculture, Fisheries and Food and the autonomous communities. This species is especially present in the southern-western areas of the peninsula, the Mediterranean coast and the Ebro basin. In general, it is found in habitats with warm waters, with a low or no flow and shallow waters — in general, wetlands and the shallow waters in rivers- and areas with agricultural activity or peri-urban areas affected by pollution. In the peninsular area, it is a competitive predator that has forced local species to move — such as the Spanish toothcarp (Aphanius iberus), the Valencia toothcarp (Valencia hispanica), the Andalusian toothcarp (Aphanius baeticus) and the three-spined stickleback (Gasterosteus aceulatus), apart from other amphibians and invertebrates. Exotic mosquitofish: strategies to survive under adverse conditions Its high fecundity, sexual precocity, tolerance to environmental pollution and competitive superiority are “factors that make its monitoring more difficult if the only strategies to preserve biodiversity in the water ecosystem are based on the improvement of water or the natural habitat,” notes researcher Oriol Cano Rocabayera, first author of the article and member of the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB and IRBio. “If some mosquitofish enter a new habitat -or when there are a few of them after a control action to remove the population- this exotic species is able to increase its fecundity rate to balance the population imbalance. However, if the population of mosquitofish is stable and abundant, the fecundity lowers but new mosquitofish are bigger and have more chances of surviving,” says Cano. Changes in water regime — building of dams, canalizations, etc. — favour the presence of certain exotic species — like the mosquitofish — that prefer water with low flow. In general, the restoration of the hydrological regime has the best strategy to control invasive species. “However, preventing the arrival of these and removing the populations of mosquitofish in the available ecosystems are the most effective actions for their control. Nevertheless, their small size, the wide range of tolerance, their diet and connectivity of water ecosystems makes this control and their removal very expensive and difficult.” The new study reveals that habitats with abundant water plants -for example, naturalized dams- and well-preserved environments improve the physical condition of mosquitofish. Therefore, the complexity of the habitat is a factor that brings more preys and shelter against the attack of the predators. “The mosquitofish’s survival in high salinity waters is difficult, and these waters are now the natural habitat where the Spanish toothcarp is limited to,” comments Cano Rocabayera. The danger of releasing exotic animals in the environment The global distribution of this invasive species — found in all continents but for the Antarctica — is related to the areas where it was introduced a century ago due the biological control of mosquitos that carried malaria. Therefore, the most recent outbreaks of tropical diseases transmitted via mosquitoes — Zika, Chikunguya and Pappataci fever — make it essential to extreme the surveillance on the effects of the introduction of these exotic fish in the local fauna, especially in tropical regions with a high biodiversity. According to the authors of the study, “we need to apply more effective control measures on the small water masses, that is, in habitats where the complete removal of the population can be guaranteed. Also, we need to raise awareness among people on the danger of releasing exotic animals in the natural environment.” //pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (adsbygoogle = window.adsbygoogle || []).push({}); Whats New Get Started Cancel Anytime
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