MI weekly selection #117
Neanderthals interbred with ancient Asians at 2 points in history
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.
Marine animals a lot larger today than ancient counterparts
Marine animals are about 150 times larger on average today than their ancient ancestors of the Cambrian period. 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.
Mice brains grow bigger with human DNA infusion
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.
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.
Fasting benefits reproduced with infusion of ketone
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. Researchers tested BHB in mice genetically engineered to have autoimmune diseases and found that it reduced their symptoms.