The implication is that there was an early divergence between North American indigenous peoples and those of Central and South America.Ruled out were hypotheses which posit that invasions subsequent to the Clovis culture overwhelmed or assimilated previous migrants into the Americas.
While technically referring to the era before Christopher Columbus' voyages of 1492 to 1504, in practice the term usually includes the history of American indigenous cultures until Europeans either conquered or significantly influenced them.
The indigenous peoples of the Americas are the pre-Columbian peoples of the Americas and their descendants.
Although some indigenous peoples of the Americas were traditionally hunter-gatherers—and many, especially in the Amazon basin, still are—many groups practiced aquaculture and agriculture.
The Portuguese and Spanish equivalents to Indian, nevertheless, could be used to mean any hunter-gatherer or full-blooded Indigenous person, particularly to continents other than Europe or Africa—for example, Alaska was a glacial refugium because it had low snowfall, allowing a small population to exist.
The Laurentide Ice Sheet covered most of North America, blocking nomadic inhabitants and confining them to Alaska (East Beringia) for thousands of years.