Studies pin down exactly when humans and Neanderthals swapped DNA

We may owe our tiny sliver of Neanderthal DNA to just a couple of hundred Neanderthals.

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[tjukken]

Se do people of African ancestry have less Neanderthal genes, or has it evened out over time?

 

[llanitedave]

I think it's interesting that the preserved admixtures seem to have only occurred "along the road" while the migrating humans were leaving Africa, but not after the groups had arrived at their various destinations. Surely there were Neanderthal groups living within Europe and Asia proper during that time. Why are the only surviving admixtures coming from the Levant area, and no trace of interbreeding once the European populations had arrived? Is it possibly because the original European Homo sapiens populations were themselves later replaced by immigrants from Asia Minor?

 

[Dputiger]

Se do people of African ancestry have less Neanderthal genes, or has it evened out over time?

People from Africa have the smallest amount of Neanderthal DNA. Initially, it was thought that people from Africa had no Neanderthal ancestry whatsoever; I think some later research has picked up traces in a few populations that were the closest to the Iberian Peninsula.

 

[The Dark]

I think it's interesting that the preserved admixtures seem to have only occurred "along the road" while the migrating humans were leaving Africa, but not after the groups had arrived at their various destinations. Surely there were Neanderthal groups living within Europe and Asia proper during that time. Why are the only surviving admixtures coming from the Levant area, and no trace of interbreeding once the European populations had arrived? Is it possibly because the original European Homo sapiens populations were themselves later replaced by immigrants from Asia Minor?

The oldest known European individual that seems to have contributed genetics to modern Europeans is Kostenki-14, a Cro-Magnon who lived around 37,000 years ago. Studies of other, older European Cro-Magnons found their genetic lineages had died out. Those earlier Cro-Magnons did interbreed with Neanderthals, but they don't constitute part of modern human genetics. They seem to have been replaced by population inflows from the Near East and Siberia.

 

[multimediavt]

Studies pin down exactly when humans and Neanderthals swapped DNA

Oooo! That article title makes the prurient sound so sciencey.

Person 1: [insultingly] "You are a monkey's uncle!"
Person 2: ][matter of factly] "Neanderthal, actually."

/s

 

[llanitedave]

The oldest known European individual that seems to have contributed genetics to modern Europeans is Kostenki-14, a Cro-Magnon who lived around 37,000 years ago. Studies of other, older European Cro-Magnons found their genetic lineages had died out. Those earlier Cro-Magnons did interbreed with Neanderthals, but they don't constitute part of modern human genetics. They seem to have been replaced by population inflows from the Near East and Siberia.

Thanks for that. I know that migrations of near-eastern farmers replaced older European hunter-gatherer populations sometime in the neolithic, and the Yamnaya people from the Ukrainian steppes added their DNA along with some cultural artifacts and the IndoEuropean languages in the early Bronze age, but I was never clear how complete that replacement was, or whether there might have been even older waves of migration.

I'd also hazard a guess that the lineages of modern humans who made it into north-eastern or far eastern Asia also had interfertile encounters with Neanderthals, along with Denisovans, and maybe there's some Eastern Neanderthal DNA mixed into those populations that we haven't ferreted out yet.

 

[benwaggoner]

People from Africa have the smallest amount of Neanderthal DNA. Initially, it was thought that people from Africa had no Neanderthal ancestry whatsoever; I think some later research has picked up traces in a few populations that were the closest to the Iberian Peninsula.

Makes sense. People and populations have been moving around and getting busy throughout human history. "Pure" populations are on a gradient of fictionality.

 

[vedekhaliwell]

Had my DNA tested by TellMeGen. Found out I was 4% Neanderthal (89% Scottish, 11% Iberian (Spain). Now I know why at least. It was an interesting read.

 

[Kesh]

swapped DNA

Is that what kids are calling it these days?

 

[ZippyPeanut]

I confess that I've swapped DNA with a few Neanderthals.

 

[benwaggoner]

I just love the irony that white folks from the Nordic countries are the least “pure” Homo sapiens, which is a wonderful slap in the face to white supremacists.

They are obsessed with racial purity, but it turns out their ancestors got banged by Neanderthals, while folks of African descent are actually the most pure genetically.

Oh, I'm sure they'd just flip this around by defining Neanderthal DNA as "vigorous" or something.

White supremicists have often flipped their pseudoscientific justifications as science changes. The conclusion is fixed, but the "facts" justifying that are highly malleable. For example, for a long time it was claimed that African children were less mature and more infant like than that of "better" races. But one the neonatality theories of human intelligence (humans have helpless babies and dangerous childbirth in order to maximize adult brain size), supremicists started talking about how African babies were MORE mature and less infant-like.

Assertions there is any genetic basis to variations in intelligence between whatever racial/regional categories can be presumed bullshit by default, given they have had a 0-for-10000 track record to date, and it is topic that has regularly caused scientific malpractice and general cognitive dissonance to the point of derangement.

 

[benwaggoner]

Those images look AI-generated.

I suppose that we'll be seeing more of this (not necessarily a bad thing, but it could be strange, if the AI isn't properly guided).

They are labeled "Artist's" so it would be a journalistic failure for them to be AI generated. I broadly trust Ars to label things in good faith. Being lazily wrong is very off-brand.

 

[benwaggoner]

I think it's interesting that the preserved admixtures seem to have only occurred "along the road" while the migrating humans were leaving Africa, but not after the groups had arrived at their various destinations. Surely there were Neanderthal groups living within Europe and Asia proper during that time. Why are the only surviving admixtures coming from the Levant area, and no trace of interbreeding once the European populations had arrived? Is it possibly because the original European Homo sapiens populations were themselves later replaced by immigrants from Asia Minor?

Interesting point. Its seems unlikely that further admixtures wouldn't still happen occasionally if populations lived side by side. Presumably some Neanderthal groups picked up some admixed descendants as well, so later admixtures could have been less impactful? Or that the rapidly growing population of recent Africans swamped the Neanderthal population so much that the percentage of Africans admixing with Neanderthals dropped rapidly, even if the percentage of Neanderthals admixing with Africans remained roughly constant.

 

[benwaggoner]

The oldest known European individual that seems to have contributed genetics to modern Europeans is Kostenki-14, a Cro-Magnon who lived around 37,000 years ago. Studies of other, older European Cro-Magnons found their genetic lineages had died out. Those earlier Cro-Magnons did interbreed with Neanderthals, but they don't constitute part of modern human genetics. They seem to have been replaced by population inflows from the Near East and Siberia.

And if newer waves mainly interbred with existing local recent-African populations, they could pick up the selected-for Neanderthal-originating traits from those locals more directly and quickly.

 

[umuhk]

They are labeled "Artist's" so it would be a journalistic failure for them to be AI generated. I broadly trust Ars to label things in good faith. Being lazily wrong is very off-brand.

The second image, at least, is a photo of the reconstruction done by Kennis & Kennis for the Espace de l’ Homme de Spy in Onoz, Belgium

 

[Nordico]

I would bet it was the Neanderthal males who mostly contributed to human gene pool. I mean, under moonlight those tall, broad-shouldered Neanderthal males probably looked mighty fine compared to short, skinny Cro-Magnons.

 

[Fred Duck]

The artist's illustration shows what the six people buried at the Ranis site, who lived between 49, 500 and 41,000 years ago, may have looked like.

So who's the seventh person? What the first photobomber's ancestor may have looked like?

Two recent studies suggest that the gene flow (as the young people call it these days) between Neanderthals and our species happened during a short period sometime between 50,000 and 43,500 years ago.

6,500 years is considered a short period of time to most people? Now I understand why when my brother borrows something from me for "a short while," I never see it again.

 

[ZenBeam]

The second image, at least, is a photo of the reconstruction done by Kennis & Kennis for the Espace de l’ Homme de Spy in Onoz, Belgium

It was even used in an Ars article back in 2016, prior to the proliferation of AI image generation: Humans started having sex with Neanderthals over 100,000 years ago.

 

[Amotabissu]

Thanks for that. I know that migrations of near-eastern farmers replaced older European hunter-gatherer populations sometime in the neolithic, and the Yamnaya people from the Ukrainian steppes added their DNA along with some cultural artifacts and the IndoEuropean languages in the early Bronze age, but I was never clear how complete that replacement was, or whether there might have been even older waves of migration.

I'd also hazard a guess that the lineages of modern humans who made it into north-eastern or far eastern Asia also had interfertile encounters with Neanderthals, along with Denisovans, and maybe there's some Eastern Neanderthal DNA mixed into those populations that we haven't ferreted out yet

This is a much earlier replacement, probably linked to climatic cycles. In oxygen isotope stage 3 (so between about 50 and 25 ka ago) there are a bunch of very rapid climatic deteriorations, the so called Heinrich events.

Ust'-Ishim, the earliest modern human in Northern Asia, a contemporary of Ranis, is not related to any present day population, and it was proposed that one of these Heinrich events about 40,000 years ago killed off these early colonists of Northern Asia, and they were then replaced by populations related to recent Asian people.

Similar things seem to have happened in Europe too, Oase for example, an about 36ka old human with a Neanderthal great-great-great-grandparent does not seem to be related to more recent populations (those are descendants of Kostenki 14, about 34 ka old).
In general it seems that you have a bunch of quick tries at expanding into these areas, but many of them were unsuccessful.

And East Asians carry a little bit more Neanderthal DNA than europeans, probably due to additional admixture events (maybe with the Siberian Neanderthals).

 

[Hmmmm?]

Would like to see some math using the assumptions outlined above that would result in the current 3 to 4 percent Neanderthal DNA in most of the world's non-African population. We could then adjust the variables to see if we find other solutions.

 

[ChrisMarshallNY]

They are labeled "Artist's" so it would be a journalistic failure for them to be AI generated. I broadly trust Ars to label things in good faith. Being lazily wrong is very off-brand.

Fair 'nuff.

But I am seeing AI-generated images that are deliberately designed to mimic hand-painted art (including brush strokes and canvas texture).

Only a matter of time. Also, artists that use AI, are likely to submit it under their imprimatur. I don't know if there's actually any guidance otherwise. At one time, airbrushing was treated in exactly the same manner.

However, like I said, it's not necessarily a bad thing. Some of the artistic images of prehistoric beasties were probably done by scientists, as opposed to artists, and aren't that compelling (but they are accurate).

AI-generated imagery is likely to be a lot more compelling, but may not be scientifically accurate, unless the scientists learn up on their prompt engineering.

Source: Former artist, specializing in dead beasties, at one time.

 

[SubWoofer2]

I would bet it was the Neanderthal males who mostly contributed to human gene pool. I mean, under moonlight those tall, broad-shouldered Neanderthal males probably looked mighty fine compared to short, skinny Cro-Magnons.

From a recent discussion with a friend on this topic: "There's lots of Neanderthal DNA scattered across all human chromosomes except the Y, which suggests another explanation entirely. They may simply have been out-bred as a result of slight genetic incompatibility. When two closely related species interbreed, the female hybrids are often fertile but the males are usually not, or sometimes are fertile when the cross is in one direction but not the other. Current thinking is that Neanderthal numbers were never large and it's possible that the only fertile offspring from the frequent sexual encounters with humans were female."

 

[Veritas super omens]

Homo sapiens have been caught en flagrante with a host of other species. The fact that it includes H. sapiens neanderthalensis is supremely unsurprising. The fact that evidence for a very short burst of successful reproduction (relative to the time frames where both populations existed in the same places) hints to me that cross breeding was generally unsuccessful. A very challenging hypothesis for which to gather additional evidence, however.

 

[e.halap]

My great-great-great uncle (he's a really great guy) would be a bit irritated that you've used his photo without consent.

 

[Batmanuel]

There's so much wrong with your comment, aside from the bigotry, that it's a pain to correct.

How is it incorrect? It is scientifically fact that the majority of white supremacists, especially those from the northern regions of Europe, have a statistically significant amount of Neanderthal f*ckers in their gene pool.

People who can trace their ancestry back to sub-Saharan Africa, on the other hand, have far fewer instances of sex with our hominid relatives in their family history.

That’s not bigotry, that’s just stating facts.

 

[Soothsayer786]

This has good romance novel potential. Lots of grunting.

 

[llanitedave]

I would bet it was the Neanderthal males who mostly contributed to human gene pool. I mean, under moonlight those tall, broad-shouldered Neanderthal males probably looked mighty fine compared to short, skinny Cro-Magnons.

You're talking about people who have no compunction about fucking sheep. I don't think Cro-magnon males would have been too standoffish towards Neanderthal women.

 

[llanitedave]

This is a much earlier replacement, probably linked to climatic cycles. In oxygen isotope stage 3 (so between about 50 and 25 ka ago) there are a bunch of very rapid climatic deteriorations, the so called Heinrich events.

Ust'-Ishim, the earliest modern human in Northern Asia, a contemporary of Ranis, is not related to any present day population, and it was proposed that one of these Heinrich events about 40,000 years ago killed off these early colonists of Northern Asia, and they were then replaced by populations related to recent Asian people.

Similar things seem to have happened in Europe too, Oase for example, an about 36ka old human with a Neanderthal great-great-great-grandparent does not seem to be related to more recent populations (those are descendants of Kostenki 14, about 34 ka old).
In general it seems that you have a bunch of quick tries at expanding into these areas, but many of them were unsuccessful.

And East Asians carry a little bit more Neanderthal DNA than europeans, probably due to additional admixture events (maybe with the Siberian Neanderthals).

That's interesting. I wonder if those events affected Australian populations in the same way? If not, would that imply that Australian populations are more closely related to the original out-of-Africa migrations than modern humans elsewhere in the world?

 

[aleph_nought]

You're talking about people who have no compunction about fucking sheep. I don't think Cro-magnon males would have been too standoffish towards Neanderthal women.

If a red-haired muscular guy like in that Neanderthal image showed up next to you during a music festival, you would.

Maybe some Cro-Magnon guys had a thing for muscular, red-headed Neanderthal women too.

Cro-Magnons weren't skinny and short either, they were supposed to be lean and tall and with darker skin.