Indigenous Peoples of The Americas - Genetics

Genetics

Main article: Genetic history of indigenous peoples of the Americas See also: Y-DNA haplogroups in Indigenous peoples of the Americas

Genetic history of indigenous peoples of the Americas primarily focus 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.

The genetic pattern indicates indigenous peoples of the Americas experienced two very distinctive genetic episodes; 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.

Human settlement of the New World occurred in stages from the Bering sea coast line, with an initial 15, 000 to 20,000-year layover on Beringia for the small founding population. The micro-satellite diversity and distributions of the Y lineage specific to South America indicates that certain indigenous peoples of the Americas populations have been isolated since the initial colonization of the region. The Na-Dené, Inuit and Indigenous Alaskan populations 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.

Scientific evidence links indigenous Americans to Asian peoples, specifically eastern Siberian populations. Indigenous peoples of the Americas have been linked to North Asian populations by linguistic factors, the distribution of blood types, and in genetic composition as reflected by molecular data, such as DNA.