Neanderthals interbred with ancient Asians at 2 points in history, studies suggest | Marine animals a lot larger today than ancient counterparts, study finds | Study: Bottlenose dolphins moved to the Mediterranean at end of last ice age
February 20, 2015
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Neanderthals interbred with ancient Asians at 2 points in history, studies suggest
Neanderthals interbred with the ancestors of Asians twice in ancient history, according to a pair of studies published in the American Journal of Human Genetics. The studies approached the same question from different directions, but came to the same conclusion, looking at why Asians have more Neanderthal DNA than Europeans. According to the studies, ancient Asians must have come in contact with Neanderthals a second time after splitting off from Europeans. The New York Times (tiered subscription model) (2/19)
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Science in the News
Marine animals a lot larger today than ancient counterparts, study finds
Marine animals are about 150 times larger on average today than their ancient ancestors of the Cambrian period, a study published in Science suggests. Researchers compared the measurements of animals from more than 17,000 genera over a 542 million-year time span. Today's smallest creatures are a tenth the size of their ancient counterparts, but the largest, whales, are more than 100,000 times bigger than their ancestors. "Classes of animals that were already big ... tended to persist longer and diversify more than classes that were, on average, smaller," said paleontologist Noel Heim, co-author of the study. Science News (2/19)
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Study: Bottlenose dolphins moved to the Mediterranean at end of last ice age
Bottlenose dolphins came to the Mediterranean Sea about 18,000 years ago, at the end of the last ice age, according to a study published in Evolutionary Biology. Before that, the Mediterranean would have been too salty for many sea creatures to live in. But as ice age glaciers melted, it became less salty and fish and other marine life moved in, followed by hungry bottlenose dolphins, researchers say. (2/19)
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Mice brains grow bigger with human DNA infusion, study finds
Brains of mice infused with human DNA grew about 12% larger than those given chimp DNA, according to a study published in Current Biology. Researchers looked at DNA segments, known as enhancers, that control nearby gene activity and found HARE5, which appears to control a gene that is part of a molecular pathway important to brain development, with the human version of the enhancer growing larger mouse brains that the chimp version. Next, the scientists want to determine whether the bigger brains make the mice any smarter. (2/19)
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Toxins cocktail helps bees fight off parasites, study suggests
Bees given a concoction of toxins, including nicotine and caffeine, were better able to ward off infection by intestinal parasites, researchers have found. The toxins, taken from plants that use the substances to discourage predators, helped reduce parasite infection levels by up to 81% in the bees and one day may help farmers and gardeners improve their bees' health. "Having bees consume these protective chemicals could be a natural treatment of the future," said evolutionary ecologist Lynn Adler, lead author of the study published in the Royal Society's Proceedings B journal. United Press International (2/18)
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Scientists measure strength of winds surrounding a black hole
NASA and European Space Agency scientists say they have calculated the size, shape and speed of winds that ring black holes, helping them understand how they affect their galaxies. Researchers looked at winds surrounding black hole PDS-456 in a galaxy 2 billion light-years from Earth, and found that the gusts contain more energy per second than a trillion suns, blowing strongly enough to stop star formation. "Now we know quasar winds significantly contribute to mass loss in a galaxy, driving out its supply of gas, which is fuel for star formation," said Emanuele Nardini, lead author of the study published in Science. The Washington Post (tiered subscription model) (2/20)
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Skin damage continues long after sun exposure, study suggests
Damage to skin from sun exposure may continue long after coming inside, and melanin, long thought to help protect skin from the damaging effects, may play a role, according to research. The study, published in Science, found that melanin is broken apart by a reaction to two enzymes forming a high energy molecule that damages cells long after sun exposure. While melanin can protect people from short-term damage, "it also causes some of it. It was an interesting finding, but it felt kind of heretical," said Douglas Brash, author of the study. The Washington Post (tiered subscription model) (2/19)
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Some airborne virus transmission possible with Ebola, study suggests
Limited airborne transmission of the Ebola virus is possible, a team of researchers write in the American Society of Microbiology's journal mBio. "It is very likely that at least some degree of Ebola virus transmission currently occurs via infectious aerosols generated from the gastrointestinal tract, the respiratory tract, or medical procedures," the scientists wrote. The paper stresses that airborne transmission of Ebola has yet to be proved and that the most common method of transmission is contact with infected body fluids. The Washington Post (tiered subscription model) (2/19)
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Fasting benefits reproduced with infusion of ketone, study finds
An immune system benefit of fasting has been reproduced by upping the dose of the ketone BHB in human cells, suppressing unwanted types of inflammation while leaving useful types alone, according to a study published in Nature Medicine. Yale School of Medicine researchers tested BHB in mice genetically engineered to have autoimmune diseases and found that it reduced their symptoms. "The goal is to get other scientists interested so that they can also study BHB in specific diseases," said study leader Vishwa Deep Dixit. New Scientist (2/19)
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Funding Watch
NIH awards $1.56M grant to Mass. scientist's Salmonella cancer treatment
The National Institutes of Health has awarded a University of Massachusetts Amherst chemical engineer a $1.56 million grant to develop a nontoxic Salmonella bacteria that can put cancer-killing agents into tumors. Neil Forbes has been working on special Salmonella bacteria attracted to tumors and can treat them without causing serious side effects. (2/19)
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