SCIENCE FILE : Groups From Europe, Asia May Be True Ancestors of Modern Humanity

The ancestors of modern humanity may have arisen in groups scattered across Europe and Asia, rather than originating in Africa, a new genetic analysis suggests.

The research, published this week in Proceedings of the National Academy of Sciences, calls into question the widely held view that modern humans evolved in Africa and then migrated into other continents.

By studying the DNA of living populations, scientists at Rutgers University discovered an unusual genetic mutation on the X chromosome, called PDHA1, that non-Africans share but Africans do not. By estimating the age of the mutation, they determined that the two groups diverged 200,000 years ago, much earlier than previous studies had shown and far earlier than the oldest known fossils of anatomically modern human beings, which date to about 130,000 years ago.

This is the first report of such a fixed DNA sequence difference between two human populations and it suggests that humans had already divided into separate groups when anatomically modern humans arose.