PAUL NICKLEN/NATIONAL GEOGRAPICDNA sequences extracted from the bones and teeth of “Naia”—a girl thought to be 15- or 16-years-old when she died around 12,000 years ago—is helping researchers to better understand when and how humans populated the Americas. This week (May 15) in Science, Washington-based archaeologist and paleontologist James Chatters and his colleagues published their morphological and genetic analyses of the ancient human, found by divers in an underwater cave near Mexico in 2007.
“With this specimen, we have evidence that the physical differences between the ancient and modern Americans came about through evolution that occurred after the Beringia migration,” said Chatters, refuting the notion that humans arrived to North America through multiple migrations from different parts of Asia and Europe.
“This girl’s maternal ancestry traces to the same source population as that of modern Native Americans,” molecular anthropologist Deborah Bolnick from the University of Texas at Austin told The Scientist.
Naia joins “Anzick-1,” a young boy uncovered in Montana who researchers described this February in Nature, among the five oldest North American humans to have been found and genetically analyzed.
WIKIPEDIA, NEPHRONA small clinical trial published in Science Translational Medicine this week (May 14) suggested that the selective serotonin reuptake inhibitor (SSRI) citalopram, which is commonly prescribed to treat depression among other things, could help stave off the formation of Alzheimer’s disease-associated amyloid plaques. Yvette Sheline from the University of Pennsylvania and her colleagues also studied the effects of citalopram in mice.
