They discover that Denisova's man also inhabited Tibet and not only Siberia

An investigation, published online May 1 in the prestigious scientific journal Nature, shows that a denisovano mandible discovered in a Tibetan Plateau cave indicates that Homo sapiens was not the first human to conquer such lands.

Until now, the only fossil remains of the Denisovans, a species related to Neanderthals, had been discovered in the Denisova cave in Siberia.

But now, a team of researchers led by Fahu Chen, from the Tibetan Plateau Research Institute; Zhang Dongjiu, from Lanzhou University; and Jean Jacques Hublin, of the Max Planck Institute of Evolutionary Anthropology, have just published the description of a 160,000-year-old jaw belonging to this same species found in Xiahe, China.

This is the first time that this species has been found outside the caves of Denisova, Siberia. "The jaw of Xiahe probably represents the oldest fossil of hominids in the Tibetan plateau," said study author, Fahu Chen. According to the expert, this ancestor had already adapted to live in this high altitude environment and little oxygen, long before the Homo sapiens reached the region.

"The discovery of a Denisovan on the plateau at 4,500 meters shows that human evolution was much more complicated than we thought," said paleoanthropologist Jean-Jacques Hublin of the Max Institute. Planck of evolutionary anthropology in Germany.

"We have Homo erectus, who lived about 2 million years ago, hominid groups of Denisovan, then our species," said Hublin at a press conference on the results of the discovery that different human species, including ours, have had bad. In doing so, we integrate genes from these ancient species into our modern human genome, with traces of DNA from denisovans detected in modern local human populations and in people as far apart as humans. Australia.

Judging by their DNA, the Denisovans shared a common ancestor with Neanderthals about 400,000 years ago. They crossed with Neanderthals and with our own species. Today, populations from East Asia, Australia, the Pacific Islands and the Americas possess Denisovan DNA.

Most of what we know about Denisovans so far comes from DNA, which was sequenced from the bones of the Altai Cave. This included a genetic variant, or mutation, called EPAS1, which was linked to the ability of Himalayans to resist hypoxia, the conditions of lack of oxygen found in heights.

"The fingerprints of the Denisovans," said Hublin, "are found in the current populations of Asia, Australia and Melanesia, suggesting that these ancient hominines have spread and occupy vast areas, but up to At present, the only fossils represented only had been identified in Denisova Cave ".

Karst Baishiya Cave

The researchers studied in detail the lower jaw found on the Tibetan plateau, specifically in the Karst Baishiya cave in Xiahe, China, at an altitude of 3,200 meters. The fossil was originally discovered in 1980 by a local monk who visited the cave to pray, who gave it to the 6th living Buddha, Gung-Thang, who brought it to his tour given at Lanzhou University.

Since 2010, Fahu Chen and Dongju Zhang, from Lanzhou University, are studying the discovery area. And in 2016, they began collaborating with the Department of Human Evolution of the Max Planck Institute to advance in the badysis of fossils.

Although the scientists found no trace of DNA in the jaw, they managed to extract the proteins from one of the molars, which they then badyzed in detail.

"The old jaw proteins are very degraded and are therefore distinctly different from modern proteins that may contaminate a sample." Our protein badysis indicates that Xiahe's jaw belonged to a population of hominins closely related to the Denisovans of Denisova Cave, "said Frido Welker, another member of the team.

A very well preserved jaw

Scientists say that the mandible, robust primitive shape and large molars still attached, is very well preserved. This suggests that it belonged to a middle Pleistocene hominin that shared anatomical features with Neanderthals and individuals of Denisova Cave.

"The dating of the jaw was at least 160,000 years old," said Chuan-Chou Shen, from the Department of Geosciences of the National Taiwan University, who established this dating, according to which "that age minimum is equal to that of the specimens, the oldest of the cave Denisova ".

"Xiahe's jaw probably represents the first hominin fossil on the Tibetan plateau, and our badyzes pave the way for a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia." ", concluded Fahu Chen.