[note 1] Traditional theories suggest that big-animal hunters crossed the Bering Strait from North Asia into the Americas over a land bridge (Beringia).

[5] Scientific evidence links Indigenous Americans to eastern Siberian populations by the distribution of blood types, and genetic composition as indicated by molecular data, such as DNA.

From 8000 to 7000 BCE (10,000–9,000 BP) the climate stabilized, leading to a rise in population and lithic technology advances, resulting in a more sedentary lifestyle during the following Archaic Period.

Researchers continue to study and discuss the specifics of Paleo-Indian migration to and throughout the Americas, including the dates and routes traveled.

[9] The traditional theory holds that these early migrants moved into Beringia between eastern Siberia and present-day Alaska 17,000 years ago,[10] at a time when the Quaternary glaciation significantly lowered sea levels.

[11] These people are believed to have followed herds of now-extinct pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets.

[24] This early Paleo-Indian period's lithic reduction tool adaptations have been found across the Americas, utilized by highly mobile bands consisting of approximately 20 to 60 members of an extended family.

[26] Small bands utilized hunting and gathering during the spring and summer months, then broke into smaller direct family groups for the fall and winter.

[33] During much of the early and middle Paleo-Indian periods, inland bands are thought to have subsisted primarily through hunting now-extinct megafauna.

[35] It has been disputed whether the Clovis culture were specialist big-game hunters or employed a mixed foraging strategy that included smaller terrestrial game, aquatic animals, and a variety of flora.

[40] The glaciers that covered the northern half of the continent began to gradually melt, exposing new land for occupation around 17,500–14,500 years ago.

In North America, camelids and equids eventually died off, the latter not to reappear on the continent until the Spanish reintroduced the horse near the end of the 15th century CE.

[44] There they would camp for a few days, perhaps erecting a temporary shelter, making and/or repairing some stone tools, or processing some meat, then moving on.

[54] Recent data from a series of archaeological sites throughout the Americas suggest that Clovis (thus the "Paleo-Indians") time range should be re-examined.

In particular, sites such as Cooper's Ferry in Idaho,[55] Cactus Hill in Virginia,[56] Meadowcroft Rockshelter in Pennsylvania,[57] Bear Spirit Mountain in West Virginia,[58] Catamarca and Salta in Argentina,[59] Pilauco and Monte Verde in Chile,[60][61] Topper in South Carolina,[62] and Quintana Roo in Mexico[63][64] have generated early dates for wide-ranging Paleo-Indian occupation.

[77] The former is the determinant factor for the number of gene lineages and founding haplotypes present in today's Indigenous Amerindian populations.

Human settlement of the Americas occurred in stages from the Bering sea coast line, with an initial layover on Beringia for the founding population.

[79][80][81][82] 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.

[93] The Archaic period in the Americas saw a changing environment featuring a warmer, more arid climate and the disappearance of the last megafauna.

Thus with the passage of time there is a pattern of increasing regional generalization like the Southwest, Arctic, Poverty, Dalton, and Plano traditions.

These regional adaptations would become the norm, with reliance less on hunting and gathering, and a more mixed economy of small game, fish, seasonally wild vegetables, and harvested plant foods.