The Big Death
August 12, 2021 4:57 PM Subscribe
New study says humans killed Neanderthals by having sex with them. A rare blood disorder discovered in Neanderthal babies was likely the result of breeding with humans, according to a new study. [...] This disorder would have made it difficult for the affected generations to reproduce — cutting their bloodline short. (The Hill, July 28, 2021) The paper: Blood groups of Neandertals and Denisova decrypted, PLoS ONE
The blood disorder is hemolytic disease of the fetus and newborn (aka HDN, HDFN, or erythroblastosis foetalis), the result of incompatible blood types (Rh incompatibility, ABO incompatibility) between gestational carrier and fetus. The Rh factor is a protein on the covering of the red blood cells. Rh factor protein on the cells = an Rh positive person; absence of Rh factor protein = the person is Rh negative. Understanding Rh Status in Pregnancy video w/traditional gender terminology. An Rh-negative gestational carrier with an Rh-positive pregnancy partner is a known risk for an HDN-affected fetus, as are certain sensitizing events which trigger antibody production.
While it was long thought that Neanderthals were all type O -- just as chimpanzees are all type A and gorillas all type B -- the researchers demonstrated that these ancient hominins already displayed the full range of ABO variability observed in modern humans. (ScienceDaily, July 30, 2021)
Ideally, modern prenatal screening identifies Rh-negative status early in pregnancy, and treatment with Rh immunoglobulin can prevent reaction to the fetus's Rh-positive red blood cells -- unless the gestational carrier has been pregnant before, and has already started making Rh antibodies. (Health problems usually do not occur during an Rh-negative expectant person's first pregnancy with an Rh-positive fetus.) Possible [mild to severe, including fetal and infant death] complications; newborn treatments are dependent on the extent of the disease.
Paper excerpt: We show that Neanderthal and Denisova were polymorphic for ABO and shared blood group alleles recurrent in modern Sub-Saharan populations. Furthermore, we found ABO-related alleles currently preventing from viral gut infection and Neanderthal RHD and RHCE alleles nowadays associated with a high risk of hemolytic disease of the fetus and newborn. Such a common blood group pattern across time and space is coherent with a Neanderthal population of low genetic diversity exposed to low reproductive success and with their inevitable demise. -Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, et al. (2021) Blood groups of Neandertals and Denisova decrypted. PLoS ONE 16(7): e0254175. https://doi.org/10.1371/journal.pone.0254175
More on HDFN: Pegoraro V, Urbinati D, Visser GHA, Di Renzo GC, Zipursky A, Stotler BA, et al. (2020) Hemolytic disease of the fetus and newborn due to Rh(D) incompatibility: A preventable disease that still produces significant morbidity and mortality in children. PLoS ONE 15(7): e0235807. https://doi.org/10.1371/journal.pone.0235807
A few Neandertal-related previouslies on MetaFilter.
The blood disorder is hemolytic disease of the fetus and newborn (aka HDN, HDFN, or erythroblastosis foetalis), the result of incompatible blood types (Rh incompatibility, ABO incompatibility) between gestational carrier and fetus. The Rh factor is a protein on the covering of the red blood cells. Rh factor protein on the cells = an Rh positive person; absence of Rh factor protein = the person is Rh negative. Understanding Rh Status in Pregnancy video w/traditional gender terminology. An Rh-negative gestational carrier with an Rh-positive pregnancy partner is a known risk for an HDN-affected fetus, as are certain sensitizing events which trigger antibody production.
While it was long thought that Neanderthals were all type O -- just as chimpanzees are all type A and gorillas all type B -- the researchers demonstrated that these ancient hominins already displayed the full range of ABO variability observed in modern humans. (ScienceDaily, July 30, 2021)
Ideally, modern prenatal screening identifies Rh-negative status early in pregnancy, and treatment with Rh immunoglobulin can prevent reaction to the fetus's Rh-positive red blood cells -- unless the gestational carrier has been pregnant before, and has already started making Rh antibodies. (Health problems usually do not occur during an Rh-negative expectant person's first pregnancy with an Rh-positive fetus.) Possible [mild to severe, including fetal and infant death] complications; newborn treatments are dependent on the extent of the disease.
Paper excerpt: We show that Neanderthal and Denisova were polymorphic for ABO and shared blood group alleles recurrent in modern Sub-Saharan populations. Furthermore, we found ABO-related alleles currently preventing from viral gut infection and Neanderthal RHD and RHCE alleles nowadays associated with a high risk of hemolytic disease of the fetus and newborn. Such a common blood group pattern across time and space is coherent with a Neanderthal population of low genetic diversity exposed to low reproductive success and with their inevitable demise. -Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, et al. (2021) Blood groups of Neandertals and Denisova decrypted. PLoS ONE 16(7): e0254175. https://doi.org/10.1371/journal.pone.0254175
More on HDFN: Pegoraro V, Urbinati D, Visser GHA, Di Renzo GC, Zipursky A, Stotler BA, et al. (2020) Hemolytic disease of the fetus and newborn due to Rh(D) incompatibility: A preventable disease that still produces significant morbidity and mortality in children. PLoS ONE 15(7): e0235807. https://doi.org/10.1371/journal.pone.0235807
A few Neandertal-related previouslies on MetaFilter.
Boy, talk about our collective mark of Cain...
posted by y2karl at 5:16 PM on August 12, 2021 [8 favorites]
posted by y2karl at 5:16 PM on August 12, 2021 [8 favorites]
I'll remain forever grateful that I was not subject to the neanderthal Tucker Carlson's pontifications on the Great Replacement Theory.
I mean, like in the day.
Same as it ever was.
posted by thecincinnatikid at 5:36 PM on August 12, 2021
I mean, like in the day.
Same as it ever was.
posted by thecincinnatikid at 5:36 PM on August 12, 2021
"it may not have been war, but love — or at least sex — that sealed our fates. "
People always make this comment about Sapiens / Neanderthal breeding, "oh look they must have loved each other because we interbred". As if the entire human history of sexual violence in inter-tribal warfare didn't exist.
posted by Nelson at 5:37 PM on August 12, 2021 [26 favorites]
People always make this comment about Sapiens / Neanderthal breeding, "oh look they must have loved each other because we interbred". As if the entire human history of sexual violence in inter-tribal warfare didn't exist.
posted by Nelson at 5:37 PM on August 12, 2021 [26 favorites]
Hmmm…. I can’t really say if this is a better or worse theory than us hunting and eating them all…
… but as fate would have it, we are now fucking ourselves to death, so…. Karma? (I mean in general… not literally)
posted by rozcakj at 5:51 PM on August 12, 2021 [1 favorite]
… but as fate would have it, we are now fucking ourselves to death, so…. Karma? (I mean in general… not literally)
posted by rozcakj at 5:51 PM on August 12, 2021 [1 favorite]
This on top of a study from almost a year ago strongly suggesting that the human Y chromosome had completely displaced the original Neanderthal Y chromosome among late period Neanderthals:
It's kind of hard to wrap your mind around.
posted by jamjam at 5:54 PM on August 12, 2021 [14 favorites]
The Neanderthal Y chromosome is much more closely related to the Y of modern humans than to the Y of Denisovans, another archaic hominin that lived in Eurasia at the same time as Neanderthals, according to a study published today (September 24) in Science. This stands in stark contrast to the rest of the nuclear genome, which has clearly placed Neanderthals and Denisovans as sister groups in a lineage that split from the ancestors of modern humans. The Y chromosome data—the first from Denisovans and the first high-coverage from Neanderthals—suggest that earlier Neanderthals had a Denisovan-like Y chromosome, but that this was replaced by the Y chromosome of modern humans after Neanderthals interbred with them between 370,000 and 100,000 years ago.And not only that. Human Mitochondrial DNA also seems to have completely displaced the original Neanderthal mitochondrial DNA:
While this wasn’t what the researchers were expecting, he notes that this is not the first time researchers have seen this pattern; the mitochondrial genome of Neanderthals is also more similar to the mitochondrial sequences of modern humans than to those of their sister group.This seems to mean that every late period male Neanderthal could trace his ancestry through an unbroken line of males back to a human male, and every late period female Neanderthal could also trace her ancestry back through an unbroken line of females to a human woman.
“It is remarkable to see that both uniparental markers, so both [the] Y chromosome and mitochondrial DNA, they show the same story,” says Cosimo Posth, a paleogeneticist at University of Tübingen in Germany. In 2017, he and colleagues analyzed material from a very early group of Neanderthals and revealed their mitochondrial DNA (mtDNA) to be more similar to the Denisovan mitochondrial genome. This finding led to what Petr says is “currently the most widely accepted model” for the patterns of mtDNA similarity: Neanderthals originally carried a Denisovan-like mitochondrial genome, but it was replaced by gene flow by mtDNA from an early lineage of modern humans that had left Africa and migrated to Eurasia, where they interbred with Neanderthals.
It's kind of hard to wrap your mind around.
posted by jamjam at 5:54 PM on August 12, 2021 [14 favorites]
Just might explain why the 'greys' are keeping their distance, they got science, they know.
posted by sammyo at 6:19 PM on August 12, 2021 [1 favorite]
posted by sammyo at 6:19 PM on August 12, 2021 [1 favorite]
This is probably the most effective and fastest way for an invasive species to eradicate a wild type of a given native.
When invaders only compete, many natives are impacted, but even if they go into local decline, extirpation can take hundreds of generations. Because resource competition is ultimately a slow pressure, in the view of community ecology of long-lived organisms with overlapping generations.
But if the invader interbreeds and successfully hybridizes, the native type can be lost quickly, even without their progeny suffering any special harm to reproductive success. In fact, interbreeding can often increase reproductive success of offspring, an effect sometimes known as 'hybrid vigor'
The example that came up recently was red mulberry (native to Eastern US) and white mulberry (native to East Asia). Tons of mulberries around the USA, and tons of native alleles. But if you look closely, you'll see almost none of the original wild type, even if the average invasive specimen has some X% native pedigree. And for that matter the number of Asian mulberries with no American Alleles is pretty small too.
This is all much creepier with great apes, but it's been going on through (pre-)history and throughout the colonial era, right up to the present day.
A lot of extinctions are not so much dying off as rapid dissolving of a population.
Anyway, this is cool research but not terribly surprising, and I'm not certain but I think the press piece is probably overselling the novelty, insofar as we've known for decades there was most likely widespread interbreeding between early Hominids.
posted by SaltySalticid at 6:28 PM on August 12, 2021 [14 favorites]
When invaders only compete, many natives are impacted, but even if they go into local decline, extirpation can take hundreds of generations. Because resource competition is ultimately a slow pressure, in the view of community ecology of long-lived organisms with overlapping generations.
But if the invader interbreeds and successfully hybridizes, the native type can be lost quickly, even without their progeny suffering any special harm to reproductive success. In fact, interbreeding can often increase reproductive success of offspring, an effect sometimes known as 'hybrid vigor'
The example that came up recently was red mulberry (native to Eastern US) and white mulberry (native to East Asia). Tons of mulberries around the USA, and tons of native alleles. But if you look closely, you'll see almost none of the original wild type, even if the average invasive specimen has some X% native pedigree. And for that matter the number of Asian mulberries with no American Alleles is pretty small too.
This is all much creepier with great apes, but it's been going on through (pre-)history and throughout the colonial era, right up to the present day.
A lot of extinctions are not so much dying off as rapid dissolving of a population.
Anyway, this is cool research but not terribly surprising, and I'm not certain but I think the press piece is probably overselling the novelty, insofar as we've known for decades there was most likely widespread interbreeding between early Hominids.
posted by SaltySalticid at 6:28 PM on August 12, 2021 [14 favorites]
But if the invader interbreeds and successfully hybridizes
I'm certainly not going to advocate for or defend the author, but Orson Scott Card's _Wyrms_ is an interesting exploration in the opposite direction. (My claim is vague enough -- and the book old enough -- that I don't think this constitutes any major spoiler.)
posted by Slothrup at 6:37 PM on August 12, 2021 [1 favorite]
I'm certainly not going to advocate for or defend the author, but Orson Scott Card's _Wyrms_ is an interesting exploration in the opposite direction. (My claim is vague enough -- and the book old enough -- that I don't think this constitutes any major spoiler.)
posted by Slothrup at 6:37 PM on August 12, 2021 [1 favorite]
In fact, interbreeding can often increase reproductive success of offspring, an effect sometimes known as 'hybrid vigor'
Isn’t this exactly the opposite of what this research is purporting to show? I think the claim is that Neanderthal/modern human first pregnancies would have resulted in a propensity for HDN that would have made subsequent pregnancies unviable in the female Neanderthal.
I don’t think this result has to do with hybridization—it’s a specific claim that interbreeding led to Neanderthal fetal mortality.
posted by mr_roboto at 6:44 PM on August 12, 2021 [7 favorites]
Isn’t this exactly the opposite of what this research is purporting to show? I think the claim is that Neanderthal/modern human first pregnancies would have resulted in a propensity for HDN that would have made subsequent pregnancies unviable in the female Neanderthal.
I don’t think this result has to do with hybridization—it’s a specific claim that interbreeding led to Neanderthal fetal mortality.
posted by mr_roboto at 6:44 PM on August 12, 2021 [7 favorites]
Well, now we know what to do when the aliens arrive.
posted by The Underpants Monster at 7:04 PM on August 12, 2021 [24 favorites]
posted by The Underpants Monster at 7:04 PM on August 12, 2021 [24 favorites]
This is probably the most effective and fastest way for an invasive species to eradicate a wild type of a given native.
Does this suggest that progressives should aggressively begin interbreeding with MAGAheads?
posted by njohnson23 at 7:05 PM on August 12, 2021 [1 favorite]
Does this suggest that progressives should aggressively begin interbreeding with MAGAheads?
posted by njohnson23 at 7:05 PM on August 12, 2021 [1 favorite]
There’s a Captain Kirk joke in there somewhere...
posted by Naberius at 7:26 PM on August 12, 2021 [10 favorites]
posted by Naberius at 7:26 PM on August 12, 2021 [10 favorites]
I often wonder to what extent modern humans saw Neandertals as truly different people. I suspect that they tolerated or despised them no more or less than they did other rival bands of modern humans, some of whom were probably bigger and hairier than them as well.
posted by Countess Elena at 7:43 PM on August 12, 2021 [6 favorites]
posted by Countess Elena at 7:43 PM on August 12, 2021 [6 favorites]
it’s a specific claim that interbreeding led to Neanderthal fetal mortality.
Right, that's probably the novel bit, thanks. I meant my comment a little more generally: I think it's interesting that we don't need any special mechanism of decreased fecundity for interbreeding to cause extinction of a given historical wild type. Even increased success can be enough to do that. Not that I disagree with the claim, just discussing the issue of interbreeding and extinction.
posted by SaltySalticid at 8:00 PM on August 12, 2021
Right, that's probably the novel bit, thanks. I meant my comment a little more generally: I think it's interesting that we don't need any special mechanism of decreased fecundity for interbreeding to cause extinction of a given historical wild type. Even increased success can be enough to do that. Not that I disagree with the claim, just discussing the issue of interbreeding and extinction.
posted by SaltySalticid at 8:00 PM on August 12, 2021
Countess Elena: I often wonder to what extent modern humans saw Neandertals as truly different people.
If early modern humans were anything like us, perhaps there was a lot of variety from group to group and individual to individual in how Neanderthals were seen? You'd have your early modern hippies who'd be, like, "We can totally live together in peace and have babies together," and you'd have your early modern imperialists who'd be, like, "Let's crush them and make them slaves and force them to have our babies."
posted by clawsoon at 8:41 PM on August 12, 2021 [7 favorites]
If early modern humans were anything like us, perhaps there was a lot of variety from group to group and individual to individual in how Neanderthals were seen? You'd have your early modern hippies who'd be, like, "We can totally live together in peace and have babies together," and you'd have your early modern imperialists who'd be, like, "Let's crush them and make them slaves and force them to have our babies."
posted by clawsoon at 8:41 PM on August 12, 2021 [7 favorites]
If all the Y chromosomes in late-Neanderthal days were from H. sapiens, then that suggests something about the nature of Human/Neanderthal interaction which is depressing enough. Now picture the last Neanderthals -- all women, of course -- wondering if they would survive their next pregnancy...
posted by CCBC at 11:41 PM on August 12, 2021 [3 favorites]
posted by CCBC at 11:41 PM on August 12, 2021 [3 favorites]
Death by snu snu indeed.
posted by JohnFromGR at 3:17 AM on August 13, 2021 [5 favorites]
posted by JohnFromGR at 3:17 AM on August 13, 2021 [5 favorites]
While non-surviving children would have been a big evolutionary pressure, it appears that they were in trouble before that:
Neanderthal populations were never large, structured in small interconnected groups (about 20 individuals) that never outnumbered 70,000 individuals at the time of their "golden age" (the "emian" interglacial at OIS 5, around 120 kya) [37]. ... Genetic data has also pointed out the low genetic diversity of Neanderthals, with a demographic depression peak in the Altai where a very consanguineous individual was found [14], and genetic continuity across Europe from 120 kya until the disappearance of the population around 40 kya [39]. This low variability is also visible in the morphology of the Neanderthals, which remained the same during the last 100 kya of their existence.posted by CheeseDigestsAll at 6:12 AM on August 13, 2021
We literally fucked Neanderthals to death.
First the Neanderthals, now the entire planet. Yay us.
posted by tommasz at 6:26 AM on August 13, 2021
First the Neanderthals, now the entire planet. Yay us.
posted by tommasz at 6:26 AM on August 13, 2021
Neanderthal 1: "Look over there, humans"
Neanderthal 2: "Fuck me dead..."
posted by acb at 7:24 AM on August 13, 2021
Neanderthal 2: "Fuck me dead..."
posted by acb at 7:24 AM on August 13, 2021
Something fairly similar happened with a feral kitten litter I've been watching online recently. The mother has Type B blood, meaning that mating with Type A males led to one litter after another passing away abruptly due to blood type mismatching (Neonatal Isoerythrolysis); the kittens absorbed antibodies against their own blood type from their mother's colostrum, leading to a rapidly fatal anemia.
The solution was to blood-test the kittens immediately after birth, isolate type-A kittens for the first 24 hours, bottle-feed them during that time and inject them with a serum synthesized from type-A blood to provide antibodies. (The colostrum is very important for passing the mother's antibodies onto newborn kittens, so bottle-fed newborns are otherwise extremely vulnerable to infection in early life.) Unfortunately, Neanderthals lacked this level of technology or understanding.
The grand poobah of Tinykittens (Shelly Roche) discusses this process here, while the end result of her efforts (happy mama and kittens) are live here.
posted by delfin at 7:48 AM on August 13, 2021 [5 favorites]
The solution was to blood-test the kittens immediately after birth, isolate type-A kittens for the first 24 hours, bottle-feed them during that time and inject them with a serum synthesized from type-A blood to provide antibodies. (The colostrum is very important for passing the mother's antibodies onto newborn kittens, so bottle-fed newborns are otherwise extremely vulnerable to infection in early life.) Unfortunately, Neanderthals lacked this level of technology or understanding.
The grand poobah of Tinykittens (Shelly Roche) discusses this process here, while the end result of her efforts (happy mama and kittens) are live here.
posted by delfin at 7:48 AM on August 13, 2021 [5 favorites]
Does this suggest that progressives should aggressively begin interbreeding with MAGAheads?
Considering MAGA is more social than bio, education is the "interbreeding" and ya, it works in a lot of cases.
posted by Mitheral at 7:55 AM on August 13, 2021 [3 favorites]
Considering MAGA is more social than bio, education is the "interbreeding" and ya, it works in a lot of cases.
posted by Mitheral at 7:55 AM on August 13, 2021 [3 favorites]
U-S-A! U-S-A!
posted by officer_fred at 9:03 AM on August 13, 2021
posted by officer_fred at 9:03 AM on August 13, 2021
I often wonder to what extent modern humans saw Neandertals as truly different people.
"He was was Homo Sapien. She was a Neanderthal. Two different families. Two different sub-species. Their friends said it couldn't work, but for these two infatuated prehistoric teenagers, true love would find a way."
posted by thivaia at 9:05 AM on August 13, 2021 [6 favorites]
"He was was Homo Sapien. She was a Neanderthal. Two different families. Two different sub-species. Their friends said it couldn't work, but for these two infatuated prehistoric teenagers, true love would find a way."
posted by thivaia at 9:05 AM on August 13, 2021 [6 favorites]
This is really gonna change the tone of that Encino Man sequel.
posted by deadaluspark at 9:28 AM on August 13, 2021 [1 favorite]
posted by deadaluspark at 9:28 AM on August 13, 2021 [1 favorite]
Once again Octavia Butler was ahead of the curve with her Xenogenesis trilogy.
posted by kokaku at 9:38 AM on August 13, 2021 [2 favorites]
posted by kokaku at 9:38 AM on August 13, 2021 [2 favorites]
What does it mean, when there were so many other hominids running around including some we were having sex with, that things that are almost but not quite human are deeply creepy?
My unfounded speculation abt a possible evolutionary reason for the uncanny valley...
posted by subdee at 10:54 AM on August 13, 2021 [5 favorites]
My unfounded speculation abt a possible evolutionary reason for the uncanny valley...
posted by subdee at 10:54 AM on August 13, 2021 [5 favorites]
If you have not seen "Border" I highly recommend it. We could say it's somewhere adjacent to this discussion if a bit further to the fantasy spectrum, I just love the hell out of how understated and just cool this movie is.
posted by elkevelvet at 11:37 AM on August 13, 2021 [2 favorites]
posted by elkevelvet at 11:37 AM on August 13, 2021 [2 favorites]
I'm convinced they still walk amongst us...
posted by ihaveyourfoot at 3:09 PM on August 13, 2021
posted by ihaveyourfoot at 3:09 PM on August 13, 2021
It's interesting to think that must have literally happened to Neanderthals that I'm personally related to but my direct Neanderthal ancestors must have been the lucky ones.
posted by bleep at 3:17 PM on August 13, 2021
posted by bleep at 3:17 PM on August 13, 2021
Unless I'm misunderstanding & Neanderthal genes only came from Neanderthal men & human women..?
posted by bleep at 3:19 PM on August 13, 2021
posted by bleep at 3:19 PM on August 13, 2021
An Indigenous people in the Philippines have the most Denisovan DNA :P
posted by kliuless at 7:34 PM on August 13, 2021 [3 favorites]
posted by kliuless at 7:34 PM on August 13, 2021 [3 favorites]
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Sounds about right.
posted by NoxAeternum at 5:02 PM on August 12, 2021 [12 favorites]