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Ancient DNA reveals pervasive directional selection across West Eurasia [pdf]
- Metacelsus 6mo agoSee also the press release: https://hms.harvard.edu/news/massive-ancient-dna-study-reveals-natural-selection-has-accelerated-recent-human-evolution https://hms.harvard.edu/news/massive-ancient-dna-study-revea... This study covers about 10,000 years of recent human evolution in Europe and West Asia. From the abstract: >in the past ten millennia, we find that many hundreds of alleles have been affected by strong directional selection. We also document one-standard-deviation changes on the scale of modern variation in combinations of alleles that today predict complex traits. This includes decreases in predicted body fat and schizophrenia, and increases in measures of cognitive performance. These effects were measured in industrialized societies, and it remains unclear how these relate to phenotypes that were adaptive in the past. We estimate selection coefficients at 9.7 million variants, enabling study of how Darwinian forces couple to allelic effects and shape the genetic architecture of complex traits.
- shadowtree 6mo agoBlank Slate hypothesis is now officially refuted, correct? Different evolutionary paths between races/regions, with impact on mental health and cognitive performance.
- Tor3 6mo agoJust where did you get that from? Certainly not from the paper.
- AlgorithmicTime 6mo ago[dead]
- tokai 6mo agoRacists are hilarious. They will twist and bend anything remotely applicable to fit and underpin their prejudices.
- kloop 6mo agoI think they're talking about this bit: > We finally observed signals of selection for combinations of alleles that today are associated with three correlated behavioural traits: scores on intelligence tests (increasing γ = 0.74 ± 0.12), household income (increasing γ = 1.12 ± 0.12) and years of schooling (increasing γ = 0.63 ± 0.13). These signals are all highly polygenic, and we have to drop 449–1,056 loci for the signals to become non-significant (Extended Data Fig. 10). The signals are largely driven by selection before approximately 2,000 years )*, after which γ tends towards zero Presumably pressure in different regions lead to different combinations of those alleles, which I think they are shorthanding a bit, but the fact that those alleles exist makes blank slate theory a kind of rough assumption
- svnt 6mo agoI haven’t had time to really dig in to the paper but these data (from only one region) are limited in their ability to compare regions, right? If anything they seem to support homogenization of intellectual capacity/mental health in Eurasia since 2kya. The methodology, if it holds up, seems to hold a lot of promise for answering questions like this in the future.
- ano-ther 6mo agoYes, they only had data for West Eurasia. > Just because an allele, SNP, or trait swept into or out of West Eurasia during this time doesn’t mean this happened only in West Eurasia. Researchers can use the new computational methods to look for directional selection in other populations worldwide that have enough ancient DNA sequences and construct a clearer picture of what’s unique to different groups and what generalizes across populations. > Reich expects that future studies will show that shared selective pressures acted on some of the same core traits across diverse human groups, even as those groups split off and migrated to different parts of the world over tens of thousands of years. https://hms.harvard.edu/news/massive-ancient-dna-study-reveals-natural-selection-has-accelerated-recent-human-evolution https://hms.harvard.edu/news/massive-ancient-dna-study-revea...
- kloop 6mo agoNo, this paper doesn't seem to talk about regional differences. The implication seems to be that it wouldn't be surprising to find differences between groups that separated more than 2kya, as there was active changes going on before that time. Not that it predicts any specific differences > If anything they seem to support homogenization of intellectual capacity/mental health in Eurasia since 2kya. I would be interested in how you came to that conclusion, unless I'm misleading your post and you specifically mean West Eurasia
- Nesco 6mo agoThere is a graph arguing “intelligence” has been positively selected in west Eurasian population in this paper according to a polygenic score (page 8 fig. 4) Now I would be quite curious to know how they constructed this polygenic score
- tptacek 6mo ago... because it's a study of West Eurasian DNA. The claim that humanity has over millennia selected for intelligence isn't all that spicy.
- Nesco 6mo agoFirst yes it is. The claims that this time period was too short to meaningfully change phenotypes in human populations was not entirely far fetched. Then to address the elephant in the room - which is the race discourse subtext let’s be honest - it’s highly unlikely that any recent selective pressure on a separated population, which resulted in meaningful phenotype adaptations, happened similarly everywhere at the same time
- svnt 6mo agoNo one in adjacent fields has been seriously engaging tabula rasa speculation from the 17th century for quite some time prior to this paper. What you think the implications are of that for your present day lived experience, that might be a different conversation.
- lukev 6mo agoTo be clear: most people who are keen on making such an argument, or who are identifying racial genetic differences as the primary takeaway of studies like this, are doing so to justify racism, either implicitly or explicitly. But that's a strawman. Racism is wrong, even if there are minor genetic variances across populations (which... seems obvious?) Variance within a population strongly dominates the weak cross-population effects, and personal history (nutrition, education, etc) strongly dominates that. And that's setting aside the moral implications of judging someone or changing your behavior towards them even if you have somehow measured them to be "less intelligent," as if that was a single axis of worth. Because, apparently, this needs to be said.
- card_zero 6mo agoThis interest in IQ has a negative effect on the concept of intelligence, never mind human unity. It attaches exaggerated importance to test scores, jobs, and school. It tends toward snobbery.
- gnerd00 6mo agoreading about Howard Gardner’s Theory of Multiple Intelligences stuck with me.. seven is a common list
- georgeburdell 6mo agoAnd yet you are also likely to argue “weather is not climate”. Differences in population characteristics of all kinds have massive societal implications and we should lean into addressing them.
- lukev 6mo agoWell if you are talking about environmental stuff (like leaded gasoline), sure. If you’re talking about trying to improve the genetics of populations at scale… yikes.
- convolvatron 6mo agopeople trying to force everyone else to accept their poorly defended notions of race superiority have a much larger social impact than any quantifiable differences in the genetics of populations.
- damnitbuilds 6mo agoI always knew I was smarter than my parents.
- vintermann 6mo agoThe dataset excites me more than the fairly vague conclusion that some SNPs possibly linked to traits were selected for (or hitched along to genes which were selected for). Genetic archaeology is just so much more exciting than this. But I bet there will be a ton more of that too, thanks to the high quality dataset.
- timmg 6mo ago> the fairly vague conclusion that some SNPs possibly linked to traits were selected for Interesting. I find that part of the paper the most exciting. We always knew selection would happen for valuable traits. But seeing demonstrations of it in the timelines we have is pretty important.
- asdff 6mo agoMakes you wonder what is being selected for currently.
- bonsai_spool 6mo agoHere's the paper - we ideally shouldn't be linking to PDFs of these things but it's paywalled https://www.nature.com/articles/s41586-026-10358-1 https://www.nature.com/articles/s41586-026-10358-1
- bcjdjsndon 6mo agoHow did they decide what made a trait adaptive?
- MarkusQ 6mo agoThe didn't decide, they observed; consistent directional pressure over thousands of years is strong evidence that an allele is being selected for.
- bcjdjsndon 6mo agoSo if it survives it's fit, if it's fit it survives? The old tautology
- Symmetry 6mo agoNot a tautology but a definition. https://en.wikipedia.org/wiki/Fitness_(biology) https://en.wikipedia.org/wiki/Fitness_(biology)
- bcjdjsndon 6mo agoBut other than it surviving, there's no way to define fitness.
- Symmetry 6mo agoIt's more reproducing than surviving. If the population of some species increases and the number of copies of some allele remains constant we could consider than gene less fit than the other alleles, in the population genetics sense. So it's frequency rather than survival that geneticists look at. But that proves that there are indeed other ways that they could have defined fitness if they wanted to.
- bcjdjsndon 6mo ago> It's more reproducing than surviving Well that's a given mate, nobody's talking about populations that dont reproduce are they? And even then you're still making the same tautological mistake.... If they survived they must have been fit
- rossdavidh 6mo agoOne of the authors of this paper, David Reich, has written a book called "Who We Are and How We Got Here", which is worth reading. My thoughts on it: https://www.goodreads.com/review/show/2605841954 https://www.goodreads.com/review/show/2605841954
- falaki 6mo agoAbsolutely worth reading.
- e40 6mo agoCreate an account to read? No thanks.
- rossdavidh 6mo agoSorry, didn't know/remember that a GR account was required just to read...
- trallnag 6mo agoBig and true