Evolutionary history of Tibetans inferred from whole-genome sequencing
The Tibetan population has been residing on high plateau for thousands of years and developed unique adaptation to the local environment. To investigate the demographic history of Tibetans and search for possible adaptive genetic variants, we performed whole-genome sequencing of 27 Tibetan individuals. We found evidence of genetic separation between Han and Tibetans around since 44 and 58 thousand years ago; however, these two populations maintained a high rate of gene flow until 9 thousand years ago. In addition to replicating two previously discovered candidate genes (EGLN1 and EPAS1) for high altitude adaptation, we also found three new candidate genes, including PTGIS, VDR and KCTD12. We confirmed the high similarity of EPAS1 gene region between Tibetans and Denisovans, but did not detect any evidence of high altitude adaptation from Denisovan gene alleles otherwise.