Interbreeding

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Denisovans, Neandertals and Human emotions

In 2015 the genome of Oase-1 was published, a Homo sapiens individual from Romania who lived 38-42 thousand years ago (ka). The study of the genetic material preserved in the mandible showed that this individual had a Neandertal ancestor as recently as four to six generations back. That was shocking…

Now we also have the genome from a long bone of a female human (Denisova 11, aka ‘Denny’) found at the Denisova Cave in Siberia, who was at least 13 years old at death according to its cortical thickness. Direct dating of the fossil showed it to be beyond the radiocarbon limit, hence it is older than 50,000 years, probably around 90-100 ka. Oase-1 now pales in comparison to the findings from Denny…

  • Denny’s DNA fragments carried alleles matching in similar proportions the Denisovan genome and the Neandertal genome. She was the daughter of a Neandertal mother and a Denisovan father.
  • The Denisovan father had more than one Neandertal ancestor in his genealogy, as recently as 300 to 600 generations back.
  • The Neandertals that contributed to the ancestry of the father were from a different population than her mother. The Neandertal mother came from a population more closely related to the Neandertals who live later in Western Europe (compared to the Vindija material from Croatia) than to the earlier Neandertals from the Denisova Cave.
  • Eastern Neandertals migrated into Western Europe after 90 ka, and/or Western Neandertals migrated to the Altai region before 90 ka and partially replaced the local population.
Denisova 11 & Oase 1

(L) Denisova 11, credit Nature vol 560 23 Aug 18. (R) Oase 1, credit Roberto Sáez

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How many interbreeding events between neandertals & sapiens?

100,000 years ago

An ancient population of Homo sapiens migrated 100 KYA from Africa into Asia. In the Near East they met a population of neandertals, probably around the Persian Gulf, the Arabian Peninsula or the eastern end of the Mediterranean Sea in Western Asia. Then an introgression occurred of Homo sapiens into Homo neanderthalensis.

We have found the genetic stretches of H. sapiens in the genome of a female neandertal from the Denisova Cave in the Altai Mountains, south Siberia. However there are no stretches of H. sapiens in the genome of western neandertals such as those from El Sidron, Spain.

This means that probably those hybrid neandertals+sapiens from 100 KYA migrated to East Asia. Then a climate change produced an expansion of the Caspian Sea, which probably prevented further interchange with those other neandertal populations going West towards Europe.

At the same time, that ancient Homo sapiens people who left Africa 100 KYA are thought to be in the roots of all the African modern humans populations. They are probably related with the 90 Ka populations from the Skhul and Qafzeh caves in Israel, as well as with the 47 human teeth dated to 80-120 Ka found in a limestone cave system in Daoxian, China.

60,000 years ago

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