Denisovans lived in Tibetan Plateau, fossil evidence shows

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  • Analysis of a fossil jawbone containing molars recovered from Baishiya Karst cave in Xiahe, Gansu, China shows Denisovans lived in the Tibetan Plateau some 1,60,000 years ago.
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  • Denisova hominins:
    (1) Denisova hominins are an extinct species or subspecies of archaic humans in the genus Homo.
    (2) Pending its taxonomic status, it currently carries temporary species or subspecies names Homo denisova, Homo altaiensis, Homo sapiens denisova, or Homo sp. Altai.
    (3) The first evidence for Denisovans or Denisova hominins was first discovered in 2008 in a cave in the Altai mountains in Siberia.
    (4) This is the first time evidence of Denisovan presence has been found outside the Denisova cave.
  • Lived at high altitude:
    (1) Fossil remains conclusively prove that Denisovans lived in the Tibetan Plateau at an altitude of 3,280 metres much earlier — 1,60,000 years ago.
    (2) It was contrary to popular belief that high altitude regions were inhabited only by modern humans dating back to less than 40,000 years.
  • What allow them to live in low oxygen environments?
    (1) Previous genetic studies have found that modern humans living in the Tibetan Plateau carried a special gene variant — EPAS1 (Endothelial PAS Domain Protein 1) — that allowed them to cope with low oxygen (hypoxia) environments typical of high altitude.
    (2) This gene variant has been found in Denisovans.
  • Gene mutation:
    (1) Possible explanation for the presence of this gene variant in the hominin is that Denisovans lived for a long time in the plateau leading to the gene mutation.
    (2) This mutation has later been passed on to modern humans.
    (3) A team led by three researchers extracted proteins from one of the molars and carried out protein analysis.
    (4) Protein analysis conclusively proved that the jawbone belonged to Denisovans.
    (5) Protein analysis also shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave
Source
the hindu




Posted by Jawwad Kazi on 2nd May 2019
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