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Friday, April 4, 2014

The oldest sequenced Human genome


A Russian artist, Nikolay Peistov uncovered the remains of a human being (H. sapiens) in Western Siberia in 2008 while he was looking for mammoth tusks as a source of ivory for his work (he carves ivory).


The find took place along the shores of Irtysh River at Ust-Ishim. Among his hoard of ivory was a bonew which turned out to be a human tighbone 45,000 years old.


The bone's genome was sequenced by a team led by Svante Pääbo, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and their findings are interesting:


Oldest human genome sequenced


This is the oldest human genome that has been sequenced (45,000 years old), and the team found that this person: had more Neanderthal DNA than modern Asians or Europeans have, and that this Neander genetic material was unevenly distributed, being found in longer sequences than those found in modern humans.


This "integrity" of the archaic sequences means that Neander - Human admixture had taken place quite recently. This is because each passing generation breaks up the DNA segments due to crossover and exchange of DNA between parents, so a more intact sequence means a more recent introgression.


The information is scarce because these findings have not been published yet in a scientific journal, they were only mentioned in an article in Science magazine [1].


Other human remains close by


Interestingly the "Denisovans" are not mentioned as part of this man's genome.


Denisova Cave is also located in Southern Siberia and it is a site that displays cultural sequences dating from 282.0 ± 56.0 Kya to roughly 9.8 Kya, including not only modern humans but also Neanderthals and the mysterious Denisovans. Denisovan ancestry has been found in Papuans suggesting human - Denisovan admixture, but Pääbo does not mention them in relation to the Ust-Ishim genome.


We should point out that there is evidence of Mid Paleolithic occupations within the 45 kya period, in the region surrounding Denisova: [2]


  • Kara-Bom. Located about 60 km (38 mi.) south of Denisova Cave. With an earliest occupation date of 43,300 and 44,000 BP.
  • Ust-Karakol 1, right beside Denisova Cave, to the south has Mousterian layesrs with dates ranging from 50,000 +- 12,000 to 35,100 BP.
  • Okladnikov, about 30 km north of Denisova Cave, along the same Amui River. has dates of 43,000 to 28,500 BP.

Any of these people could have been contemporaries of the Ust-Ishim man.


sites in Siberia

Sites in Siberia mentioned in the text. Copyright © 20143 by Austin Whittall

Long before him, Hominids have inhabited these parts of Siberia for several hundreds of thousands of years [2]:


"According to Arkhipov (1999), the earliest human occupation of eastern and northeastern Siberia (for example, Berezhekovo site in the Yenisei River basin) could have occurred during the Tobolian Interglacial [...] about 380,000 - 260,000 years ago, though only a few sites may correspond to this time interval (such as Berezhekovo and Diring Yuriakh). [...]
At Berezhekovo, thermoluminescence (TL) dates of 130,000+ -10,000 years above the cultural layer, and 540,000 + -12,000 years below the cultural layer were obtained (Arkhipov 1999) [...] At Diring Yuriakh, an open air site in central Yakutia, the 370,000 - 270,000 year determinations by TL dating (Waters et al. 1999; Carlson 2001)..." [2]


Mal'ta boy


Younger than those ancient remains, and even younger than the Ust-Ishim remains are those from Mal'ta:


  • The specimen (MA-1) from Mal'ta in South-Central Siberia, is a modern H. Sapiens 24,000 years old.
  • American Indians share between 14 and 38% of their autosomal ancestry with him.
  • Genetically, MA-1 is closer to contemporary Native Americans than to Northeast Asians.
  • However he is different from Amerindians: he lacks shoveled incisors and his nuclear and mtDNA haplogroups (hg) are different from those found in America:
    • His Y chromosome is hg R; common in India and Western Eurasia yet much younger than the hg Q found in very high frequencies in the Americas (and a small region in Northern Central Siberia.
    • His mtDNA is hg U, which is not found in America or East and South Asia and is very frequent in Western Eurasia, India and North Africa.

Considering that 20,000 years separate Mal'ta and Ust-Ishim yet Mal'ta appears to be closer to Europeans than to East Asians, it will be interesting to find out the Y and mtDNA hg of Ust-Ishim. Will they be ancestral to Mal'ta's? Since American Natives have a higher proportion of Neanderthal genes than other groups from this region, could they be closer to the Ust-Ishim people than Eastern Asians? Did the Ust-Ishim move on, into America 45 ky ago?


We will have to be patient and wait for the final paper.


Sources


[1] Ann Gibbons, (2014), News & Analysis. Human Evolution. Oldest Homo sapiens Genome Pinpoints Neandertal Input. Science 28 March 2014: Vol. 343 no. 6178 p. 1417. DOI: 10.1126/science.343.6178.1417
[2] Anatoly P. Derevianko, Alexander V. Postnov, Eugeny P. Rybin, Yaroslav V. Kuzmin and Susan G. Keates, (2005). The Pleistocene peopling of Siberia: A review of environmental and behavioural aspectsIndo-Pacific Prehistory Association Bulletin 25, 2005 (Taipei Papers, Vol 3). pp. +57



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall © 

1 comment:

  1. An Irish tribe was uncovered brewing Bushmills in an earthen hert 65 ky ago near Cork...all well preserved and smiling. The oldest pickled humanoids.

    ReplyDelete