The roughly uniform techno-complex pattern known as Clovis appears in North and Central American sites from at least thirteen thousand five hundred years ago onward, but South American sites of equal antiquity do not share the same consistency and exhibit increasingly diverse cultural patterns.

The "Clovis-first" and Paleo-Indian hypothesis do not adequately explain complex lithic stage tools appearing in South America.

The current most widely accepted view among scientists is that the indigenous South Americans were part of the first wave of migrant hunters who came into the Americas from Asia, either by land, across the Bering Strait, or by coastal sea routes along the Pacific, or both.

The short chronology theory posits the first movement beyond Alaska into the New World occurring no earlier than fifteen thousand to seventeen thousand years ago, followed by successive waves of immigrants.

The long chronology theory proposes that the first group of people entered the hemisphere at a much earlier date, possibly twenty-one thousand to forty thousand years ago, with a much later mass secondary wave of immigrants.