Origins & Settlement Patterns INFORMATION

Land Bridge Theory Page 2

Archaeologists long thought the first Americans were the Clovis people, who were said to have reached the New World some 13,000 years ago from northern Asia.

But new archaeological finds prove that humans reached the Americas thousands of years before that.

These discoveries, along with insights from genetics and geology, have prompted reconsideration of where these pioneers came from, when they arrived, and what route they took into the New World.

In more than a dozen studies geneticists examined modern and ancient DNA samples from Native Americans, looking for telltale genetic mutations or markers that define major human lineages known as haplogroups.  They found that native peoples in the Americas stemmed from four major founding maternal haplogroups -- A, B, C and D -- and two major founding paternal haplogroups -- C and Q.  To find the probably source of these haplogroups, the teams then searched for human populations in the Old World whose genetic diversity included all the lineages.  Only the modern inhabitants of southern Siberia, from the Altai Mountains in the west to the Amur River in the east, matched this genetic profiles, causing them to believe that the ancestors of the first Americans came from an East Asian homeland.