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atomfullerene t1_iv1bwys wrote

To get Neanderthal mitochondria today, you need an unbroken chain of mother-daughter ancestry going all the way back to the Neanderthal. At no point in that entire chain could there be a mother who had only sons, because then the mitochondrial line would be lost.

So we can't really tell much by the absence of mitochondrial dna....it's just too easy to lose by pure chance.

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Skutten t1_iv1j2jr wrote

This is the correct answer and no other conclusions are valid outside of this. I really recommend anyone interested in the subject to read "Who we are and how we got here" by David Reich*. The book explains how mtDNA works and talks about our Neanderthal genes, among other very interesting things, i.e. how they have "found" ghost ancestors in our DNA, people/species that have to have existed but there are no findings of them yet.

*P.S. I myself got the book recommendation from a fellow Redditor in this sub, thank you!

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nodeciapalabras OP t1_iv1qz8m wrote

I disagree... If interspecies reproduction were close to 2%, which is possible given the molecular DNA we share, given the same ratio of survival (this is an assumption) the individuals with neardenthal mitochondrias should be close to this 2% nowadays. I think this is just an statistical thing... If you are a human being alive, there is for sure a straight chain of women above you. It's proven that all them are Sapiens. But at the same time, if there isn't any other explanation, it's highly unlikely there aren't any nearthental women in this chain for any alive human being today.

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atomfullerene t1_iv1wnhr wrote

2% DNA doesn't mean 2% interspecies reproduction....there's not a direct relationship between numbers like that. You can get to 2% DNA from a relative handful of crosses. As this paper shows only a few hundred crosses, basically one a generation across the whole range overlap, could account for the observed level of Neanderthal DNA in our genomes.

>But at the same time, if there isn't any other explanation, it's highly unlikely there aren't any nearthental women in this chain for any alive human being today.

Not really. It's very easy for mitochondrial DNA lineages to go extinct. For any particular lineage to stick around, it's like tossing a coin and coming up heads every single generation in a row. Even in the large population of humans, it's not surprising random chance would eliminate all neanderthal mitochondria.

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