Denisovan

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
The Denisova Cave, where the "X woman" was found
Denisova Cave is located in Russia
Denisova Cave
Denisova Cave
Location of Denisova Cave in the Altai Mountains of Siberia

The Denisovans or Denisova hominins are archaic humans in the genus Homo. They may be an extinct species or subspecies.

They were first discovered in March 2010 in the Denisova Cave in the Altai Mountains in Siberia. This cave that has also been inhabited by Neanderthals and modern humans.[1][2][3]

A finger bone fragment of a juvenile female was discovered. She lived about 41,000 years ago, with about 3% to 5% of the DNA of Melanesians and Aboriginal Australians and around 6% in Papuans deriving from Denisovans.[4][5][6]

The mitochondrial DNA (mtDNA) of the finger bone showed it was genetically distinct from Neanderthals and modern humans. The nuclear genome from this specimen suggested that Denisovans shared a common origin with Neanderthals.[7]

DNA analysis has indicated that modern humans, Neanderthals, and the Denisova hominin last shared a common ancestor around 1 million years ago.[8]

The mtDNA analysis also suggested that this species was the result of a migration out of Africa that came between a migration by Homo erectus individuals and later ones by some ancestors of most modern humans.[8]

Fossils[change | change source]

So far, the fossils of four distinct Denisovans from Denisova Cave have been identified through their DNA: Denisova 2, Denisova 3, Denisova 4, and Denisova 8. Denisova 2 and Denisova 3 are young females,and Denisova 4 and Denisova 8 are adult males. [9]

Anatomy[change | change source]

So far, only a finger bone, a toe bone and two teeth are the only body parts that have been found.  The finger bone is from a woman.  It is broader than a human finger.  This fact suggests that Denisovans were more robust than any modern humans.

Mitochondrial DNA analysis[change | change source]

The mtDNA from the finger bone differs from that of modern humans by 385 nucleotides in the mtDNA strand out of approximately 16,500. This  is more than the difference between modern humans and Neanderthals, which is around 202 bases.[3]

References[change | change source]

  1. David Leveille (2012). "Scientists map an extinct Denisovan girl's genome". PRI's The World,. Retrieved 31 August 2012.
  2. Brown, David (2010), "DNA from bone shows new human forerunner, and raises array of questions", Washington Post
  3. 3.0 3.1 Krause, Johannes; et al. (2010), "The complete mitochondrial DNA genome of an unknown hominin from southern Siberia", Nature, 464 (7290): 894–97, Bibcode:2010Natur.464..894K, doi:10.1038/nature08976, PMID 20336068
  4. "Callaway, Ewen (2011). "First Aboriginal genome sequenced". Nature. doi:10.1038/news.2011.551. 
  5. "About 3% to 5% of the DNA of people from Melanesia (islands in the south-west Pacific Ocean), Australia and New Guinea as well as aboriginal people from the Philippines comes from the Denisovans." Oldest human DNA found in Spain – Elizabeth Landau's interview of Svante Paabo
  6. Harmon, Katherine (2012). "Humans interbred with Denisovans". Scientific American. Retrieved 2016-08-24.
  7. Carl Zimmer (22 December 2010). "Denisovans Were Neanderthals' Cousins, DNA Analysis Reveals". NYTimes.com. Retrieved 22 December 2010.name="Callaway.
  8. 8.0 8.1 Katsnelson, Alla 2010. New hominin found via mtDNA. The Scientist (24.03.10)
  9. Slon, Viviane et al 2017. A fourth Denisovan individual. Science Advances 3 (7): e1700186. doi:10.1126/sciadv.1700186. PMC 5501502. PMID 28695206.