A paper published today in Nature (Chen, Fahu et al., A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau, doi 10.1038/s41586-019-1139-x ), identifies a lower jaw from a cave in Xiahe, China as belonging to a Densiovan, and dates it as 160,000 years old.
The abstract says:
"Denisovans are members of a hominin group who are currently only known directly from fragmentary fossils, the genomes of which have been studied from a single site, Denisova Cave in Siberia. They are also known indirectly from their genetic legacy through gene flow into several low-altitude East Asian populations and high-altitude modern Tibetans6. The lack of morphologically informative Denisovan fossils hinders our ability to connect geographically and temporally dispersed fossil hominins from Asia and to understand in a coherent manner their relation to recent Asian populations. This includes understanding the genetic adaptation of humans to the high-altitude Tibetan Plateau, which was inherited from the Denisovans. Here we report a Denisovan mandible, identified by ancient protein analysis, found on the Tibetan Plateau in Baishiya Karst Cave, Xiahe, Gansu, China. We determine the mandible to be at least 160 thousand years old through U-series dating of an adhering carbonate matrix. The Xiahe specimen provides direct evidence of the Denisovans outside the Altai Mountains and its analysis unique insights into Denisovan mandibular and dental morphology. Our results indicate that archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene epoch and successfully adapted to high-altitude hypoxic environments long before the regional arrival of modern Homo sapiens.
This is significant for several reasons:
- It is a second site with Denisovan fossils other than the original cave in the Altai mountains.
- It puts the Denisovans in a high altitue environment: the Baishiya Karst Cave is set at 3,280 m (10,500 ft) in the Tibetan Plateau.
- Present human populations in that area have inherited a Denisovan gene (found in the Altai cave remains), that gives them the ability to survive the lack of oxygen encountered at high altitudes. Now there is a Denisovan jaw bone in the right location: the Tibetan Plateau, where the Tibetans with this gene live (the Nepalese Sherpas also have it).
The age is also interesting: 160,000 years old. This is in the same range as the age of the Altai cave: Denisovans were living in the Altai cave at least 200,000 years ago and continued living there until about 55,000 years ago. Neanderthals overlapped them, and lived in the cave between around 190,000-100,000 years ago.
The mandible was discovered in 1980, and only now has it been identificed through protein analysis as belonging to a Denisovan.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2019 by Austin Whittall ©
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