Migration into the continents Anthropological and genetic evidence indicates that most Amerindian people descended from migrant people from North Asia (Siberia) who entered the Americas across the Bering Strait or along the western coast of North America in at least three separate waves. In Brazil, particularly, most native tribes who were living in the land by 1500 are thought to be descended from the first Siberian wave of migrants, who are believed to have crossed the Bering Land Bridge at the end of the last Ice Age, between 13,000 and 17,000 years before the present. A migrant wave would have taken some time after initial entry to reach present-day Brazil, probably entering the Amazon River basin from the Northwest. (The second and third migratory waves from Siberia, which are thought to have generated the Athabaskan, Aleut, Inuit, and Yupik people, apparently did not reach farther than the southern United States and Canada, respectively).[5] An analysis of Amerindian Y-chromosome DNA indicates specific clustering of much of the South American population. The micro-satellite diversity and distributions of the Y lineage specific to South America indicates that certain Amerindian populations have been isolated since the initial colonization of the region.[6]
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