linguistic:translation, stylistic:tone, structural:expansion
Genetic research

Genetic history of Indigenous peoples of the Americas primarily focuses on Human Y-chromosome DNA haplogroups and Human mitochondrial DNA haplogroups. "Y-DNA" is passed solely along the patrilineal line, from father to son, while "mtDNA" is passed down the matrilineal line, from mother to offspring of both sexes. Neither recombines and thus Y-DNA and mtDNA change only by chance mutation at each generation with no intermixture between parents' genetic material. Autosomal "atDNA" markers are also used but differ from mtDNA or Y-DNA in that they overlap significantly. AtDNA is generally used to measure the average continent-of-ancestry genetic admixture in the entire human genome and related isolated populations.

Genetic comparisons of the mitochondrial DNA (mtDNA) and Y-chromosome of Native Americans to that of certain Siberian and Central Asian peoples (specifically Paleo-Siberians, Turkic, and historically the Okunev culture) have led Russian researcher I.A. Zakharov to believe that, among all the previously studied Asian peoples, it is "the peoples living between Altai and Lake Baikal along the Sayan mountains that are genetically closest to" Indigenous Americans.

Some scientific evidence links them to North Asian peoples, specifically the Indigenous peoples of Siberia, such as the Ket, Selkup, Chukchi, and Koryak peoples. Indigenous peoples of the Americas have been linked to some extent to North Asian populations by the distribution of blood types, and in genetic composition as reflected by molecular data, and limited DNA studies.

The common occurrence of the Asian mtDNA haplogroups A, B, C, and D among eastern Asian and Native American populations has been noted. Some subclades of C and D that have been found in the limited populations of Native Americans who have agreed to DNA testing bear some resemblance to the C and D subclades in Mongolian, Amur, Japanese, Korean, and Ainu populations.

Available genetic patterns lead to two main theories of genetic episodes affecting the Indigenous peoples of the Americas; first with the initial peopling of the Americas, and secondly with European colonization of the Americas. The former is the determinant factor for the number of gene lineages, zygosity mutations, and founding haplotypes present in today's Indigenous peoples of the Americas populations.

The most popular theory among anthropologists is the Bering Strait theory, of human settlement of the New World occurring in stages from the Bering Sea coastline, with a possible initial layover of 10,000 to 20,000 years in Beringia for the small founding population. The micro-satellite diversity and distributions of the Y lineage specific to South America indicate that certain Indigenous peoples of the Americas populations have been isolated since the initial colonization of the region. The Na-Dené, Inuit, and Indigenous populations of Alaska exhibit haplogroup Q (Y-DNA) mutations, however are distinct from other Indigenous peoples of the Americas with various mtDNA and atDNA mutations. This suggests that the earliest migrants into the northern extremes of North America and Greenland derived from later migrant populations.

Multiple recent findings on autosomal DNA and full genome revealed more information about the formation, settlement, and external relationships of the Indigenous peoples of the Americas to other populations. Native Americans are very closely related to the Paleosiberian tribes of Siberia, and to the ancient samples of the Mal'ta–Buret' culture (Ancient North Eurasians) as well as to the Ancient Beringians. Native Americans also share a relatively higher genetic affinity with East Asian peoples. Native American genetic ancestry is occasionally dubbed as "Amerindian". This type of ancestry largely overlaps with "Paleosiberian" ancestry but is differentiated from "Neo-Siberian" ancestry which represents historical expansions from Northeast Asia and is today widespread among Siberian populations. The ancestors of Native Americans used a single migration route, most likely through Beringia, and subsequently populated all of the Americas in a time range between 25,000 and 15,000 years ago. Possible contact between Native Americans and Polynesians dates back to 1,400 years ago. Previously hypothesized "Paleo-Indian" groups turned out to be genetically identical to modern Native Americans. The controversial claim that the first peoples came from Europe via the North Atlantic, based on an ostensible similarity in stone-tool technology between the Solutrean culture of Pleistocene Europe and Clovis in North America, was undermined by the genome of the Anzick Clovis child, which sits squarely on the branch of Ancestral Native American peoples. No ancient or present-day genome (or mtDNA or Y chromosome marker) in the Americas has shown any direct affinities to Upper Palaeolithic European populations.

The date for the formation of the Indigenous peoples of the Americas gene pool ranges from 36,000 to 25,000 years ago, with their internal diverging being around 21,000 years ago, during the settlement of the Americas. Native Americans formed from the admixture of a lineage that diverged from Ancient East Asian people around 36,000 years ago somewhere in Southern China, and subsequently migrated northwards into Siberia where they merged with a Paleolithic Siberian population known as Ancient North Eurasians (ANE), deeply related to European hunter-gatherers, giving rise to both Indigenous peoples of Siberia and Ancestral Native Americans. Both Paleo-Siberians and Ancestral Native Americans derive between 32 and 44% of their ancestry from Ancient North Eurasians (ANE), and 56–68% ancestry from Ancient East Asians. Based on a 2023 mitochondrial DNA study, a subsequent wave of migration from Northern China, originating near the present-day cities of Beijing and Tianjin, occurred as recently as 9000 BCE, following a previously unknown coastal route from Asia to America.