Early Americans Arrived Thousands of Years Earlier Than Previously Believed

The team's findings are outlined in a review article in the journal Science entitled "The Late Pleistocene Dispersal of Modern Humans in the Americas," which synthesizes new data suggesting the migration from Alaska started about 15,000 years ago.

This theory is supported by not only archaeological evidence, but also from genetic evidence from living and ancient populations, says Ted Goebel, an anthropology professor at Texas A&M and associate director of Texas A&M's Center for the Study of the First Americans. He conducted the research with Michael R. Waters, a fellow anthropology professor at Texas A&M and director of the Center for the Study of the First Americans, and Dennis H. O'Rourke, an anthropology professor at the University of Utah.

Previous theories stated that the first migrants spread from Beringia to Tierra del Fuego over a few centuries about. Goebel says scientists have concluded that the peopling of America was a much more complex process.

The team focused primarily on molecular genetic, archaeological and human skeletal evidence to create a working model that explains the dispersal of modern humans across the New World.

Molecular geneticists have used refined method and an increasing sample of living populations and ancient remains to provide information on the Old World origins of the first Americans, the timing of their initial migration to the New World and the number of major dispersal events.

Archaeologists have found new sites and reinvestigated old ones using new methods to explain how early populations colonized North and South America.