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Denisovan mitochondrial DNA found in Tibetan cave

Date: 09 November 2020 Tags: Miscellaneous

Issue

International team of researchers has extracted genetic material from the sediments in Baishiya Karst Cave and identified mitochondrial DNA (mtDNA) from Denisovans.

 

Background

 This discovery is the first time Denisovan DNA has been recovered from a location that is outside Denisova Cave in Siberia.

 

Details

  • Denisovans are an extinct hominin group initially identified from a genome sequence determined from a fragment of a finger bone found at Denisova Cave in the Altai Mountains in southern Siberia.

  • Subsequent analyses of the genome have shown that Denisovans diverged from Neanderthals 400,000 years ago and that at least two distinct Denisovan populations mixed with ancestors of present-day Asians.

  • The only physical remains of Denisovans discovered so far in Siberia are a fragmentary finger bone, three teeth, and a skull fragment, all of which were found at Denisova Cave.

  • The findings indicate that Denisovans occupied the high-altitude cave as early as 100,000 years ago, and possibly as recently as 45,000 years ago, as well as at a point in-between.

  • Finding Denisovan DNA on the Tibetan Plateau itself is surprising. Evidence of archaic hominins 2,000 m above sea level is unusual.

  • This suggests that the Denisovans may have evolved adaptations to high altitude, much like modern Tibetans.

  • The Denisovan fossil and their mtDNA from Baishiya Karst Cave indicate that early modern humans coexisted in Asia with other archaic hominins.

  • Like Neanderthals, Denisovan populations intermixed with modern humans as they dispersed into Asia.

  • Denisovans were part of a web of now-extinct populations that contributed to the current human gene pool and shaped the evolution of our species.

 

Neanderthal

  • Neanderthals are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago.

  • They most likely went extinct due to competition with, or extermination by, immigrating European early modern humans or due to great climatic change, disease, or a combination of these factors.