The Denisov DNA found on the Tibetan plateau: the first case outside Siberia

Denisov DNA found on the Tibetan plateau

For the first time outside Siberia, the scientists discovered the Denisov DNA. The remnants of genetic data are found in the Tibetan Plateau, and they date back to a period from 100 thousand to 60 thousand years. The preliminary conclusions of the scientists are surprising: they do not exclude that the ancient human ancestors, that are extinct now, could have lived on the roof of the world for at least a hundred thousand years.

On the Tibetan plateau, the archaeological work was carried out in the area of the Baishiya karst cave. There, in the layers of sediment, the scientists extracted the Denisov's mitochondrial DNA. An archaeologist-geologist Dongjiu Zhang of Lanzhou University believes that the find indicates how a humanoid people inhabited the highland area about 100 thousand years ago.

And then the period of population was repeated again, but 60 thousand years ago. And these are the first samples of the Denisov's DNA that were found outside Siberia. The deposits in the cave, from which the DNA was extracted, date back to the period of 50-30 thousand years ago. If further research confirms this age estimate, then it is likely that some of the Denisovans could survive on the Tibetan plateau and meet the first people who reached this place about 40 thousand years ago.

If that assumption is correct, then the ancient people who settled in an unusual for them region with thin air could acquire special genetic traits that are beneficial for the environment. And it could have happened as a result of the connection with the Denisovites and the birth of new people.

Modern Tibetans may carry the Denisovan variant of the gene that promotes survival at high altitudes. In a karst cave in sediments, a fossil of the lower jaw was discovered. It belonged to a Denisovite that lived in this place about 160 thousand years ago.

The calculation of the period was carried out according to the structure of the jaw protein, and not according to the DNA, therefore the scientists still had questions about the evolutionary identity of the find.

But a study of the mitochondrial DNA of the Denisovans, found in the layers of deposits, showed the presence of close links with the mitochondrial DNA of the Denisovans in the Denisova Cave, located about 2.8 thousand kilometers north-west of the Tibetan plateau.

D. Zhang et al. Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau. Science. Vol. 370, October 30, 2020, p. 584. doi: 10.1126/science.abb6320.