Archaeology Augments Tibet's Genetic History—Response

Abstract

We thank Brantingham et al. for their interest in our study; we agree that both molecular and archaeological evidence should be used to understand the demographic history of the Tibetan people. Our Report focused not on the demographic history of the Tibetan population, but rather the selection acting on specific putatively adaptive mutations segregating in the Tibetan population. We included some limited demographic analyses because they helped illuminate our results regarding natural selection. The real demographic model is clearly likely to be more complex than the simple models of two populations diverging from each other. For example, Zhao et al. ([ 1 ][1]) used mitochondrial DNA to argue that late settlers of the Tibetan plateau may not have entirely replaced the original population but that a small proportion of them carry mitochondrial DNA lineages tracing back to Late Paleolithic inhabitants on the plateau. If this is the case, even if the EPAS1 variant was present in the early inhabitants of Tibet, strong selection would be needed to increase its frequency in the modern Tibetan gene pool. The understanding that the majority of the current population of the Tibetan plateau may trace their genetic ancestry back to quite recent immigrants into Tibet, even though humans have lived in Tibet for a much longer time—possibly with some continuity of culture—is important for understanding the difference between inferences based on archaeology and inferences based on genetics. 1. [↵][2] 1. M. Zhao 2. et al ., Proc. Natl. Acad. Sci. U.S.A. 106, 21230 (2009). [OpenUrl][3][Abstract/FREE Full Text][4] [1]: #ref-1 [2]: #xref-ref-1-1 View reference 1 in text [3]: {openurl}?query=rft.jtitle%253DProc.%2BNatl.%2BAcad.%2BSci.%2BU.S.A.%26rft_id%253Dinfo%253Adoi%252F10.1073%252Fpnas.0907844106%26rft_id%253Dinfo%253Apmid%252F19955425%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [4]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoicG5hcyI7czo1OiJyZXNpZCI7czoxMjoiMTA2LzUwLzIxMjMwIjtzOjQ6ImF0b20iO3M6MjU6Ii9zY2kvMzI5LzU5OTgvMTQ2Ny4yLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==