(Credit: University of Oklahoma)
New York, June 21 (IANS) DNA tests have confirmed that the earliest population to settle in the high valleys of the Himalayas were indeed East Asians of high altitude origin.
The genetic make-up of high-altitude Himalayan populations has remained remarkably stable despite cultural transitions and exposure to outside populations through trade, the findings showed.
"In this study, we demonstrate that the Himalayan mountain region was colonised by East Asians of high altitude origin, followed by millennia of genetic stability despite marked changes in material culture and mortuary behaviour," said senior author of the study Christina Warinner, Professor at the University of Oklahoma in the US.
The study was published in the journal Proceedings of the National Academy of Sciences.
The high altitude transverse valleys of the Himalayas were among the last habitable places permanently colonised by prehistoric humans due to the challenges of resource scarcity, cold stress and hypoxia.
The modern populations of these valleys, who share cultural and linguistic affinities with peoples found today on the Tibetan plateau, were commonly assumed to be the descendants of the earliest inhabitants of the Himalayan arc.
However, this assumption had been challenged by archaeological and osteological evidence suggesting these valleys may have been originally populated from areas other than the Tibetan plateau, including those at low elevation.
To address the problem, Warinner and colleagues sequenced the nuclear and mitochondrial genomes of eight high-altitude Himalayan individuals dating to three distinct cultural periods spanning 3,150 to 1,250 years before present.
The authors compared these ancient DNA sequences to genetic data from diverse modern humans, including four Sherpa and two Tibetans from Nepal.
All eight prehistoric individuals across the three time periods were most closely related to contemporary highland East Asian populations -- the Sherpas and Tibetans.
The findings strengthen the evidence that the diverse material culture of prehistoric Himalayan populations is the result of acculturation or culture diffusion rather than large-scale gene flow or population replacement from outside highland East Asia.
