posted
As you might know, the human genome contains portion of Nendrthal's DNA, and that can mean, that they interbreed.
I am wondering, is there alternative way, that humans got those DNAs? I know it sounds weird, coming from a biologist, since you only inherit your genome from your parents.
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posted
As I understand it, the consensus amongst geneticist is the Neanderthal DNA in our genome is most likely a result of it always being there as opposed to interbreeding.
Four possible scenarios of genetic mixture involving Neandertals. Scenario 1 represents gene flow into Neandertal from other archaic hominins, here collectively referred to as Homo erectus. This would manifest itself as segments of the Neandertal genome with unexpectedly high divergence from present-day humans. Scenario 2 represents gene flow between late Neandertals and early modern humans in Europe and/or western Asia. We see no evidence of this because Neandertals are equally distantly related to all non-Africans. However, such gene flow may have taken place without leaving traces in the present-day gene pool. Scenario 3 represents gene flow between Neandertals and the ancestors of all non-Africans. This is the most parsimonious explanation of our observation. Although we detect gene flow only from Neandertals into modern humans, gene flow in the reverse direction may also have occurred. Scenario 4 represents old substructure in Africa that persisted from the origin of Neandertals until the ancestors of non-Africans left Africa. This scenario is also compatible with the current data. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5100745/figure/F6/?report=objectonlyPosts: 3 | From: USA | Registered: Jun 2019
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posted
Thank you eroy22003 for your reply. It is new to me, what you wrote. It seems like, some people are so eager to impose only one type of theory. That is not science.
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quote:Originally posted by eroy22003: [QB] As I understand it, the consensus amongst geneticist is the Neanderthal DNA in our genome is most likely a result of it always being there as opposed to interbreeding.
There are differing opinions in the scientific community not a consensus but more weighing in for interbreeding
posted
There are human remains, notably in Iberia, which are obviously hybrids of neandertalensis with sapiens. Interbreeding did occur.
If the neandertal DNA were already present in the sapiens genome, then it would be in the genome of Africans as much as it is present in Eurasians. But it is not.
Some neandertalensis alleles are deleterious in sapiens, and it is apparent that hybrids generally have a reproductive disadvantage. However, some H.n. alleles are useful, and so did not disappear, but proliferated.
I've read the opinion of some geneticists that a male sapiens-female neandertalensis hybrid could not be brought to term and would miscarry, so that all the original hybrids had to be the result of a male neandertalensis with a female sapiens.
This issue is more complicated than the question of sapiens-neandertalensis interbreeding, as there are at least five non-sapiens species whose DNA has been found in modern sapiens: 1 in W-Central Africa, and 2 more in Eurasia besides neandertalensis and denisova.
-------------------- Nican Tlaca Posts: 139 | From: Piedmont, Virginia | Registered: Jan 2020
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