NY Times: Most geneticists agree that Native Americans are descended from Siberians who crossed into America 26,000 to 18,000 years ago via a land bridge over the Bering Strait. But while genetic analysis of modern Native Americans lends support to this idea, strong fossil evidence has been lacking.
Now a nearly complete skeleton of a prehistoric teenage girl, newly discovered in an underwater cave in the Yucatán Peninsula, establishes a clear link between the ancient and modern peoples, scientists say.
Writing in the journal Science, the researchers report that they analyzed mitochondrial DNA — genetic material passed down through the mother — that was extracted from the skeleton’s wisdom tooth by divers. The analysis reveals that the girl, who lived at least 12,000 years ago, belonged to an Asian-derived genetic lineage seen only in Native Americans.