Friday, October 30, 2020

New Ancient Denisovan mtDNA

For today’s Buddhist monks, Baishiya Karst Cave, 3200 meters high on the Tibetan Plateau, is holy. For the ancient Denisovans, extinct hominins known only from DNA, teeth, and bits of bone found in another cave 2800 kilometers away in Siberia, it was a favorite rest stop. Last year, researchers proposed that a jawbone found long ago in the Tibetan cave was Denisovan, based on its ancient proteins. But archaeologist Dongju Zhang of Lanzhou University and her team were on a quest for more definitive evidence. So in December, 2018, they began to dig. This week, Zhang’s team reports the first Denisovan ancient DNA found outside Denisova Cave: mitochondrial DNA gleaned not from fossils, but from the cave sediments themselves. Precise dates show the Denisovans took shelter in the cave 100,000 years and 60,000 years ago, and possibly as recently as 45,000 years ago when modern humans were flowing into Asia.

From here via Razib Khan at his Gene Expression blog

There has been circumstantial evidence that this was the case for a while, but finding Denisovan ancient DNA at a new location with a quite recent timeframe is helpful in expanding our understanding of this archaic species of hominins.


DDeden said...

Did you see this?

Denisovan DNA In The Genome Of Early East Asians

In 2006, miners discovered a hominin skullcap with peculiar morphological features in the Salkhit Valley of the Norovlin county in eastern Mongolia. It was initially referred to as Mongolanthropus and thought to be a Neandertal or even a Homo erectus. The remains of the "Salkhit" individual represent the only Pleistocene hominin fossil found in the country.

The skullcap found in the Salkhit Valley in eastern Mongolia belonged to a woman who lived 34,000 years ago. Analyses showed: She had inherited about 25 percent of her DNA from Western Eurasian [Credit: Institute of Archaeology, Mongolian Academy of Sciences]

Ancient DNA extracted from the skullcap shows that it belonged to a female modern human who lived 34,000 ago and was more related to Asians than to Europeans. Comparisons to the only other early East Asian individual genetically studied to date, a 40,000-year-old male from Tianyuan Cave outside Beijing (China), show that the two individuals are related to each other. However, they differ insofar that a quarter of the ancestry of the Salkhit individual derived from western Eurasians, probably via admixture with ancient Siberians.

DDeden said...

Also at the same time 35ka, the EDAR mutation took off, and, obsidian mining in Japan, there may have been lots of migrations due to climate or technology.

In the news: Upper Paleolithic humans “mined” stone from Mount Takaharayama to produce trapezoid and other stone tools 35,000 years ago

Humans may have trekked up a mountain 35,000 years ago in what is now Tochigi Prefecture to dig up raw obsidian ore to process into stone tools, archaeologists say.

andrew said...

Thanks for the heads up. I hadn't seen that one.