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The study of the genetics and archaeogenetics of the ethnic groups of South Asia aims at uncovering these groups' genetic history. The geographic position of India makes Indian populations important for the study of the early dispersal of all human populations on the Eurasian continent. Studies based on mtDNA variation have reported genetic unity across various Indian sub–populations.〔〔〔〔 Conclusions of studies based on Y Chromosome variation and Autosomal DNA variation have been varied, although many researchers argue that most of the ancestral nodes of the phylogenetic tree of all the mtDNA types originated in the subcontinent. Recent genome studies appear to show that most South Asians are descendants of two major ancestral components, one restricted to South Asia and the other component shared with Central Asia, West Asia and Europe.〔〔 It has been found that the ancestral node of the phylogenetic tree of all the mtDNA types typically found in Central Asia, the West Asia and Europe are also to be found in South Asia at relatively high frequencies. The inferred divergence of this common ancestral node is estimated to have occurred slightly less than 50,000 years ago.〔 In India the major maternal lineages, or mitochondrial DNA Haplogroups, are M, R and U, whose coalescence times have been approximated to 50,000 BP.〔 The major paternal lineages represented by Y chromosomes are haplogroups R1a1, R2, H, L and J2.〔 Many researchers have argued that Y-DNA Haplogroup R1a1 (M17) is of autochthonous Indian origin.〔〔 However, proposals for a Central Asian origin for R1a1 are also quite common.〔〔 ==Overview== All the mtDNA and Y-chromosome lineages outside Africa descend from three founder lineages: * M, N and R haplogroups for mtDNA and * C, D and F haplogroups for the Y-chromosome. All these six founder haplogroups can be found in the present day populations of South Asia. Moreover, the mtDNA haplogroup M and the Y-chromosome haplogroups C and D are restricted to the area ''east'' of South Asia. All the West Eurasian populations derive from the N and R haplogroups of mtDNA and the F haplogroup of the Y-chromosome. Endicott et al. state that these facts are consistent with the hypothesis of a single exodus from East Africa 65,000 years ago via a southern coastal route, with the West Eurasian lineages separating from the South Asian lineages somewhere between East/Northeast Africa and South Asia. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Genetics and archaeogenetics of South Asia」の詳細全文を読む スポンサード リンク
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