Tibetans Partly Denisovan ?
Posted: Wed Jul 02, 2014 2:16 pm
Nielsen and his colleagues investigated how Tibetans might have developed their adaptation. Frustratingly, the research team's computer models could not at first explain how Tibetans evolved their pattern of EPAS1 mutations as quickly as they apparently did.
Now, the scientists find Tibetans apparently inherited this pattern of mutations, or haplotype, from a recently discovered extinct lineage of humans known as the Denisovans.
Recent analysis of DNA from Denisovan fossils revealed the ancestors of modern humans apparently interbred with Denisovans, whose genetic footprint extended from Siberia to the Pacific Islands of Oceania. About 0.2 percent of DNA of mainland Asians and Native Americans is Denisovan in origin.
The researchers looked for the Tibetan pattern of EPAS1 mutations in 26 different modern human populations across the world, as well as in Neanderthal and Denisovan genomes. They found only Denisovans possessed this haplotype too, as did a small percentage of Han Chinese. This suggests the ancestors of Tibetans inherited this pattern of mutations either from Denisovans or relatives of Denisovans.
The researchers suggest this pattern of mutations might also exist in other Asian populations adapted to high altitudes. These include the Sherpas of Nepal and certain Mongolian populations. Nielsen and his colleagues detailed their findings in the July 3 issue of the journal Nature.
http://www.sott.net/article/281257-Tibe ... hal-cousin
Now, the scientists find Tibetans apparently inherited this pattern of mutations, or haplotype, from a recently discovered extinct lineage of humans known as the Denisovans.
Recent analysis of DNA from Denisovan fossils revealed the ancestors of modern humans apparently interbred with Denisovans, whose genetic footprint extended from Siberia to the Pacific Islands of Oceania. About 0.2 percent of DNA of mainland Asians and Native Americans is Denisovan in origin.
The researchers looked for the Tibetan pattern of EPAS1 mutations in 26 different modern human populations across the world, as well as in Neanderthal and Denisovan genomes. They found only Denisovans possessed this haplotype too, as did a small percentage of Han Chinese. This suggests the ancestors of Tibetans inherited this pattern of mutations either from Denisovans or relatives of Denisovans.
The researchers suggest this pattern of mutations might also exist in other Asian populations adapted to high altitudes. These include the Sherpas of Nepal and certain Mongolian populations. Nielsen and his colleagues detailed their findings in the July 3 issue of the journal Nature.
http://www.sott.net/article/281257-Tibe ... hal-cousin