[From an interview with  Douglas Owsley, a physical anthropologist with the Smithsonian Institution, and co-author of the book, Kennewick Man: The Scientific Investigation of an Ancient American Skeleton.]

How has Kennewick Man changed our understanding of the way the Americas were peopled? 

I think we're coming to realize that people got into the New World thousands of years earlier than what we'd anticipated and by different means of locomotion than we'd expected. I don't doubt people were going back and forth across the Bering land bridge.

But people of this time period also knew about boats, probably made of skin. If you were following the coastline in this time period, there would have been places where glaciers would have projected out into the ocean. So you'd have to either walk over them, which would've been difficult, or skirt around them using boats.

I think there were no boundaries. You have people following along the coastline. There is also good evidence there are not just people coming in at this time period from the Pacific side, of which Kennewick Man is a representative. My colleague Dennis Stanford has been finding more and more evidence that indicates that people got into the New World on the Atlantic side across the pack ice from Spain and France 17,000 to 20,000 years ago.