Neanderthal DNA Exists in Humans, But One Piece Is Mysteriously Missing

[BootinUp]

Longish article, different explanations are proposed for the missing Y chromosome.
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Genetic studies are revealing ever more about the links between modern humans and these long-gone relatives – most recently that a rush of interbreeding between our species occurred in a relatively short burst of time around 47,000 years ago. But one mystery still remains.

The Homo sapiens genome today contains a little bit of Neanderthal DNA. These genetic traces come from almost every part of the Neanderthal genome – except the Y sex chromosome, which is responsible for making males.

So what happened to the Neanderthal Y chromosome? It could have been lost by accident, or because of mating patterns or inferior function. However, the answer may lie in a century-old theory about the health of interspecies hybrids.

snip

The missing Neanderthal Y may then be explained by "Haldane's rule". In the 1920s, British biologist J.B.S. Haldane noted that, in hybrids between species, if one sex is infertile, rare or unhealthy, it is always the sex with unlike sex chromosomes.

https://www.sciencealert.com/neanderthal-dna-exists-in-humans-but-one-piece-is-mysteriously-missing

[FirstLight]

1. Ooh! cool! thanks for this...

I'm finishing up a unit in Anthropolgy and Evolution - "Stones & Bones"

We got past all the background base knowledge you need for micro-evolution (genetic mutation etc) and then moved into speciation... then we JUST jumped into the chapters on Ancient Primates, and next is the early hominids.

So, we're about to do the deep dive into Europe, Neanderthal, Denosivian (sp?) etc...

so I'm definitely bookmarking this for future reference! Thanks

[Warpy]

2. Well, it wouldn't, not for long

Breeding between Sapiens and Neandertal was most likely infrequent. And like most cross species breeding we know about today, the males were infertile. Fertile females obviously existed, since we're here. I don't know how many generations it took to produce fertile males desending down the hybrid female line..

The Neandertals were wiped out by the Campanian Ignimbrite Event, they were just in the wrong place at the wrong time. Not enough stragglers were left to produce non sterile males through successive generations.

It probably wasn't all bad for the sterile males, any horny females who wanted their fun without the consequences would have found them extremely attractive.

Before modern human men get too confident, the human Y is most likely on its way out, too, but for another reason.. Here is a good discussion of why it's not going to be a problem: https://geneticsunzipped.com/transcripts/2023/03/23/bye-bye-y

[speak easy]

3. The Neandertals were in decline long before the Campanian Ignimbrite Event.

If anything, the aftermath of the eruption, a colder climate. would have suited them.

[Warpy]

6. Yes, they were. Genetic studies of their later remains

have shown increasing prevalence of the diseases of inbreeding. Yes, they were on the skids before that volcano blew up.

[speak easy]

7. But they were not "in the wrong place at the wrong time"

The ejecta from the Campanian eruption headed over Greece towards the Russian steps

Campanian Ignimbrite’s contribution to the Middle to Upper Palaeolithic transition.

Tephra fallout, together with the attendant episode of Fenno-Scandinavian ice cap and peripheral tundra advance on land (top dashed line), suggests a reduction of the area available for human settlement in Europe of up to 30% (represented by the ash fallout gap with isopach tephra deposits in cm). Anatomically modern humans would have gravitated towards repopulating this gap after ecosystem

https://www.nature.com/articles/srep21220

[yonder]

4. +1. Interesting reading, sorta kept up but would grandly fail if tested, which applies to the OP's link as well.

[Dan]

5. I don't understand, all one has to do is look at MTG.