Denisovans: Primitive humans lived at high altitudes

[muriel_volestrangler]

Scientists have found evidence that an ancient species of human called Denisovans lived at high altitudes in Tibet.
...
While the researchers could not find any traces of DNA preserved in this fossil, they managed to extract proteins from one of the molars, which they then analysed applying something called ancient protein analysis.

"Our protein analysis shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave," said co-author Frido Welker, from the University of Copenhagen, Denmark.

The discovery may explain why individuals studied at Denisova Cave had a gene variant known to protect against hypoxia (oxygen deficiency) at high altitudes. This had been a puzzle because the Siberian cave is located just 700m above sea level.

https://www.bbc.co.uk/news/science-environment-48107498

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 Tibetans. 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.

https://www.nature.com/articles/s41586-019-1139-x

[friendly_iconoclast]

1. I found the altitude of the cave in question in a NY Times article: 10,700 ft/3261m

https://www.nytimes.com/2019/05/01/science/denisovans-tibet-jawbone-dna.html