First Americans came from Siberia 15,000 years ago
Adam Rifkin stashed this in Anthropology!
A DNA Search for the First Americans Links Amazon Groups to Indigenous Australians:
15,000 years ago, humans began crossing a land bridge called Beringia that connected their native home in Eurasia to modern-day Alaska. Who knows what the journey entailed or what motivated them to leave, but once they arrived, they spread southward across the Americas.
The prevailing theory is that the first Americans arrived in a single wave, and all Native American populations today descend from this one group of adventurous founders. But now there’s a kink in that theory. The latest genetic analyses back up skeletal studies suggesting that some groups in the Amazon share a common ancestor with indigenous Australians and New Guineans. The find hints at the possibility that not one but two groups migrated across these continents to give rise to the first Americans.
“Our results suggest this working model that we had is not correct. There’s another early population that founded modern Native American populations,” says study coauthor David Reich, a geneticist at Harvard University.