Ancestral Origins and Genetic History of Tibetan Highlanders.
Am J Hum Genet
; 99(3): 580-594, 2016 09 01.
Article
em En
| MEDLINE
| ID: mdl-27569548
ABSTRACT
The origin of Tibetans remains one of the most contentious puzzles in history, anthropology, and genetics. Analyses of deeply sequenced (30×-60×) genomes of 38 Tibetan highlanders and 39 Han Chinese lowlanders, together with available data on archaic and modern humans, allow us to comprehensively characterize the ancestral makeup of Tibetans and uncover their origins. Non-modern human sequences compose â¼6% of the Tibetan gene pool and form unique haplotypes in some genomic regions, where Denisovan-like, Neanderthal-like, ancient-Siberian-like, and unknown ancestries are entangled and elevated. The shared ancestry of Tibetan-enriched sequences dates back to â¼62,000-38,000 years ago, predating the Last Glacial Maximum (LGM) and representing early colonization of the plateau. Nonetheless, most of the Tibetan gene pool is of modern human origin and diverged from that of Han Chinese â¼15,000 to â¼9,000 years ago, which can be largely attributed to post-LGM arrivals. Analysis of â¼200 contemporary populations showed that Tibetans share ancestry with populations from East Asia (â¼82%), Central Asia and Siberia (â¼11%), South Asia (â¼6%), and western Eurasia and Oceania (â¼1%). Our results support that Tibetans arose from a mixture of multiple ancestral gene pools but that their origins are much more complicated and ancient than previously suspected. We provide compelling evidence of the co-existence of Paleolithic and Neolithic ancestries in the Tibetan gene pool, indicating a genetic continuity between pre-historical highland-foragers and present-day Tibetans. In particular, highly differentiated sequences harbored in highlanders' genomes were most likely inherited from pre-LGM settlers of multiple ancestral origins (SUNDer) and maintained in high frequency by natural selection.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Filogenia
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Genoma Humano
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Povo Asiático
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Fluxo Gênico
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
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Male
País como assunto:
Asia
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Oceania
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article