A paragraph in this paper: Neanderthal and Denisova tooth protein variants in present-day humans) by Clément Zanolli , Mathilde Hourset, Rémi Esclassan, Catherine Mollereau (Published: September 13, 2017https://doi.org/10.1371/journal.pone.0183802) caught my eye. It pointed out an anomaly: Africans sharing a trait with Neanderthals and Denisovans!
This is what it says:
"The finding in living Africans of rare derived polymorphisms that were present in Neanderthals (Fig 2: ENAM G389S, 5%) or Denisova (Fig 3: CEMP1 R80H, 0.5%) is difficult to reconcile with the fact that interbreeding of AMH with Neanderthals occurred out of Africa [75, 76]. However, as mentioned above, this could be explained by the inside Africa admixture between the ancestors of AMH and archaic hominins, or by the possible back migration of Neanderthal gene flux. Further genome analysis of the Neanderthal and Denisova polymorphisms in AMBN, ENAM, and CEMP1 certainly deserves attention as they could trace back an African ancestor common to Neanderthals, Denisova and early anatomically modern humans."
Well, it is not "difficult to reconcile" if the fact is wrong and AMH interbred with Neanderthals inside Africa...
The ENAM G389S variant is found not only in Africa at 5% but also at very low frequencies in the Americas 0.3% (maybe imported by African slaves or perhaps a genuine Amerindian-Neanderthal admixture). Its global prevalence is only 1.3% and is virtually absent in Asia and Europe. Denisovans carried the ancestral "G" type, found in chimps and gorillas. Neanderthals and modern humans carry the derived "S" type.
They also found a some proteins in Denisovans (K55 E variant) that appear at 26% frequency among Africans and 7% globally (the highest outside of Africa being in America at 2% and far lower elsewhere). This is the ancestral type, found in Denisovans, chimpanzees and modern humans, but it was not found in Neanderthals.
The paper also hints at an admixture in Africa between H. Sapiens and some archaic homo 35,000 years ago:
"Most of the amino acid changes are found in the dentin and enamel proteins that are encoded by genes located in two close clusters on the chromosome 4 (Fig 4) and supposed to derive from an ancestral gene encoding a secretory calcium-binding protein [68]. These clusters fall apart from known haplotypes on chromosome 4 and do not correspond to candidate Neanderthal or Denisovan gene flow regions in non-African living humans [69, 70]. However, a signal of archaic introgression in the locus 4qMB179 on chromosome 4 has been evidenced in Central African populations, and is supposed to result from admixture with an archaic Homo some 35 kya [71]."
Admixture with archaic hominins in Africa would "enrich" the diversity of African DNA and therefore contradict the prevailing theory that Africans are more diverse and therefore they are the "original" source of humanity.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2018 by Austin Whittall ©
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