People arrived in North and South A

People arrived in North and South America in three distinct waves instead of one, with most modern Native Americans descending from a single batch of migrants who slipped into Alaska before traveling south into the rest of the hemisphere, according to a new analysis of more than 364,000 DNA sequences from 69 Native American and Siberian groups."This is the most comprehensive survey of genetic diversity in Native Americans so far," the authors wrote. "Our analyses show that the great majority of Native American populations — from Canada to the southern tip of Chile — derive their ancestry from a homogeneous 'First American' ancestral population, presumably the one that crossed the Bering Strait more than 15,000 years ago."Following that first group of settlers were two populations intimately familiar to Alaskans — the ancestors of modern Athabascans, Tlingits, Eyaks and Haidas who speak Na-Dene languages (the study focused on the Chipewyan people of the Northwest Territories rather than any modern Alaskan group) and the ancestors of those who speak Aleut and Eskimo languages, the authors said.But even these Arctic peoples — still carrying evidence of their East Asian ancestry in their genes — inherited most of their genetic heritage from the very first arrivals.