Before anyone jaunts too far down the road of literal survivorship bias, I'd like to point out that it'd be incredibly premature—or perhaps way too late—to speculate much on the social side of things.

Elsewhere I've seen some people making hay about exactly whose-males were with whose-females, and want to point out that it's normal for genes to cause asymmetries.

In particular, consider the modern problem of RH incompatibility [0], where one pairing is more likely to end up with a child than an identical but gender-bent one.

[0] https://my.clevelandclinic.org/health/diseases/21053-rh-fact...

or even as simple as mitochondria...

Boy it so tempting to come up with "just so" stories to explain this. And so frustrating that we will probably never be able to determine the answer. but still cool.

I always wondered if Neanderthals disappeared or if they melted in the general human population since it was quite possible their numbers were much smaller than Homo Sapiens.

Presumably this hypothesis is meant to explain why there is this observed asymmetry in the type of Neanderthal DNA we find in modern human populations that contain them, which is entirely autosomal. With none in the mitochondrial form, which is exclusively passed down along the female line, and also none in the Y-chromosome form, which is exclusively passed down along the male line.

Without weighing on the validity of their hypothesis that one or both sides found the other“especially attractive”, an alternative mechanism that could explain why we only see Neanderthal autosomal DNA in modern humans could be that only the female offspring of male-Neanderthal and female-sapiens pairings were reproductively fertile. This is more commonly the case in interspecies hybrids, see Haldane’s rule.

why no mitochondrial then?

Because these hybrids would contain mtDNA from their human female line. Neanderthal mtDNA could only be passed down by Neanderthal females.

And because none of those are found in any modern human populations, we can conclude no humans today are descended from female Neanderthals. Though whether hybridized descendants from male-sapiens female-Neanderthal pairings never existed, or they did exist for some time then eventually went extinct, we cannot currently say with certainty.

Strictly speaking we don't know that. It may always turn up an extremely rare Y or mtdna variant which was thought to be extinct. Ötzi's mt like was thought to be extinct (Wikipedia page even still says so) but very recently a North African man took a full mtdna test and it turned out he had the same. That could happen with neanderthal variants too for all we know.

> we can conclude no humans today are descended from female Neanderthals.

that looks worded wrong, strictly speaking. if there's a male neanderthal ancestor, then he very likely has a neanderthal mom or grandma or ... great^N grandma for some N.

Ok yes, you're right. Guess I meant to say: no humans today are descended from someone between a male sapenis-female Neanderthals hybrid.

One reason for that might be the size of the baby homo sapiens scull/head upon birth. Bigger brain might have meant female Neanderthals couldn’t give birth to Homo Sapiens babies. Just a theory.

Neanderthals had larger cranial capacity than modern humans.

Possibly not at birth?

I can’t believe people are being so flippant describing this story (“sex life”) when there’s a high probability that the differential is because neanderthal males were raping homo sapiens females. Neanderthals had much higher muscle mass and were much stronger than homo sapiens.

We don't know that, and we don't know that neanderthal males were more prone to rape than homo sapiens males. And it's weird to even apply the 21st century concept of rape to prehistoric societies.

I have to agree, theres a bizarre and worrying internet-brained hysterical element to that original comment which betrays a totally absent education.

the casual title is because of the scientific and prehistoric nature of the subject

However, if one happens to be a race science type, there’s a lot of profit that can be made telling suggestive “just so” stories about which homo sapiens genetic lines are allegedly tainted with a larger proportion of neanderthal genes, or however that’s supposed to work.

It would be an afrocentric trope because it’s Europeans that have the most neanderthal genes.

And because Europeans have the most Neanderthal genes, it's all "Neanderthals are smarter than we thought!" and not "are Europeans the missing link?"

Or that during the migration men died or were captured and killed.

> the differential is because neanderthal males were raping homo sapiens females

They were simply more attractive to homo sapiens females because of more chest hair, muscles, and better defined jawline.

Well, ya. Of course it was rape. And in retaliation we genocided them, hence the lack of Y and mRNA.

> and mRNA

This might be seen as a bit of a nitpick but I believe you mean mtDNA (mitochondrial).

>And in retaliation we genocided them

This is far from being the only or even main explanation to their extinction.

The Neanderthal populations were extremely inbred, so I'd guess that was a bigger factor to their decline.

In those days, there were γίγαντες and also after.

evidently, i'm not the only one who has watched Ancient Aliens (though with the fam for historical mysteries blended with hilarity)