May 4, 2009

American Indians came from single group

U.S.-led researchers say they have determined the ancestors of American Indians migrated to the New World from one ancestral Asian population.

The international group of scientists said their genetic studies support virtually without exception the single ancestral population theory.

The scientists, led by Noah Rosenberg of the University of Michigan, scrutinized DNA samples of people from 31 modern-day Asian populations, 19 Native American, one Greenlandic and two western Beringian populations.

Our work provides strong evidence that, in general, Native Americans are more closely related to each other than to any other existing Asian populations, except those that live at the very edge of the Bering Strait, said Kari Britt Schroeder, a lecturer at the University of California-Davis, and first author of the study.

While earlier studies have already supported this conclusion, what's different about our work is that it provides the first solid data that simply cannot be reconciled with multiple ancestral populations, said Schroeder.

The study that also included scientists from Sweden's Uppsala University; the Universities of Kansas, Chicago, Pennsylvania and Illinois; Johns Hopkins University; the Russian Academy of Sciences; and the University of California-San Francisco appears in the journal Molecular Biology and Evolution.