I’m RazibKhan on Clubhouse. Follow me when you get on. I have a members-only “Club” I’m inviting my followers to. I’m going to use it to have conversations and “rooms”. But I can only add members in batches of 10-50 right now, so going through it manually. If you follow me on Clubhouse and want to be a member, just leave a comment with your handle, and I’ll add you manually.
In 2014 when BEu was created as a construct to explain the greater affinities of Mesolithic European hunter-gatherers with East Eurasians than modern Europeans*, I probably would have been a little surprised that a mostly BEu individual had still not been discovered in the ancient DNA. After all, we had seen Ma’lta boy answer the question of who the mysterious “Siberians” were that left an imprint all over West Eurasia. Ma’lta was part of an ancient Paleo-Siberian group, the Ancient North Eurasians (ANE), who no longer exist in “pure” form, but contributed ancestry (or more precisely were related to groups that did so) to hunter-gatherers in Eastern Europe and the ancestors of New World populations.
No such luck with BEu. In fact, BEu as a construct is so vaguely understood that research groups can estimate that populations are 10% BEu, or 40% BEu, contingent upon various specifications in their model. In the middle 2010’s one of the scientists involved in the groups working in this space and using BEu as a construct even told me that this population may never have existed in pure form anyhow (not Iosif Lazaridis to be clear).
Basically, there is still not a lot of clarity. BEu seems to have diverged before Neanderthal admixture into the non-African lineage ~55,000 years ago. It also seems to have been subject to the long bottleneck of all non-Africans. A very plausible model that BEu occupied the southern Middle East, while non-basal Eurasians occupied the northern Middle East, seem to be the highest probability to me. The authors of this preprint argue that the Basal Eurasian ur-heimat might be in and around the Persian Gulf. I laughed when I read that because it reminds me of the early 20th century “Lost Civilization Underwater” motif. But it could be true.
I would hazard to guess dates, but I think the separation and later (early) admixture of BEu and non-BEu people in the Near East is probably strongly conditional on the paleoclimate data, which I am not fluent in.
* BEu ancestry came into Europe with Neolithic farmers, so affinities between Mesolithic hunter-gatherers and East Asians is higher than between modern Europeans and East Asians.
The Reich lab released a bunch of data in January 2021. Someone emailed me about the format. I converted their earlier release to PLINK (PEDIGREE) format, and they wondered if I could do the same again for this relase. I did so. Remember that the “FAMILY ID” is the population as identified from their annotation files.
Long-time readers of this blog know I’m quite interested in the history of Central Asia. This region of the world is “back in the news.” The Uyghurs of the Tarim basin are in the eye of the storm, with the Chinese government’s totalitarian apparatus zeroed in on them.
But is this so surprising? I would say no. The northern half of Xinjiang is “Dzungaria”, named after a collection of groups called “Dzungar Mongols.” But very few Mongols live in Dzungaria today. This is because 250 years ago they were ethnically cleansed by the Manchu Empire. The Qing dynasty.
Just a note: I want to drum up more reviews for the Unsupervised Learning podcast. Can you guys please post a review if you haven’t? What matters most is Apple Podcasts, though I’m grateful for any Stitcher reviews.
I’ve got thirteen episodes up now, that should be enough to get a sense of the podcast.
Finally, if you are a paid subscriber, I’ll be talking to Lee Jussim this week. I think the core readers of this weblog will enjoy that.
I was busy. Then we lost power for days. So no updates on this blog. But a lot has happened while I’ve been trying to keep warm. Discuss. I have papers to read from what I can tell.
Follow me @razibkhan on Clubhouse. I have internet and plan on doing my usual 7 PM PDT event, this time on the genetics of Europe (and going to push through on the Substack post on Italy now).
Both Ruy Teixeira and John Judis, authors of The Emerging Democratic Majority, have turned on the major public message of their book, that demography is destiny and the Democrats just had to wait for the future (the book itself is more subtle, but you can ask Francis Fukuyama how much people look beyond the title).
Teixeria’s essays of late have been very interesting though, as he doesn’t seem to keen on many partisan pieties. His latest, Did the Democrats Misread Hispanic Voters?:
… The reality of the Hispanic population is that they are, broadly speaking, an overwhelmingly working class, economically progressive, socially moderate constituency that cares above all, about jobs, the economy and health care.
…
Clearly, this constituency does not harbor particularly radical views on the nature of American society and its supposed intrinsic racism and white supremacy. Rather, this is a population that overwhelmingly wanted to hear what the Democrats had to offer on jobs, the economy and health care. But the Democrats could not make the sale with an unusually large number of Latino voters in a year of economic meltdown and coronavirus crisis. This suggests there was an opportunity cost to the political energy devoted to issues around race which simply were not that central to the concerns of Hispanic voters and the more radical aspects of which were unpopular with these voters.
This point struck me because in his conversation with Julia Galef David Shor emphasizes over and over how extremely left-wing Democratic operatives are. Shor claims that about 1/3rd of his team as Civis were Democratic Socialists of America members. One individual wasn’t DSA because DSA was too conservative. Shor also implies that Joe Biden’s flip on the Hyde Amendment was dictated by a staff revolt.
My personal experience with friends in academia is that many of them simply are not aware of how socially liberal they are. Their view of what a “conservative” view on a social issue is is just out of touch often. I know for a fact many academics were shocked that California rejected affirmative action again. It’s a majority-minority state. They had expectations.
I wonder about this same problem with Latinx voters, who are overwhelmingly Democrats, but unless they are part of the intelligentsia are not socially bleeding-edge liberal (and don’t consider themselves “Latinx”). A lot of times white academics I know just don’t want to admit that “BIPOC” and Latinx people don’t really agree with them on a lot of these cultural issues, since they believe their views are derived from antiracism, so when nonwhite people disagree it must be false consciousness.
For academics, “this is academic.” But what if the Democrat’s operative class is subject to the same problem?
(I assume the equivalent with Republicans is that they always believe they haven’t “explained” economic libertarianism well to a populace that really isn’t too keen on it)
Under neutral theory, the level of polymorphism in an equilibrium population is expected to increase with population size. However, observed levels of diversity across metazoans vary only two orders of magnitude, while census population sizes (Nc) are expected to vary over several. This unexpectedly narrow range of diversity is a longstanding enigma in evolutionary genetics known as Lewontin’s Paradox of Variation (1974). Since Lewontin’s observation, it has been argued that selection constrains diversity across species, yet tests of this hypothesis seem to fall short of explaining the orders-of-magnitude reduction in diversity observed in nature. In this work, I revisit Lewontin’s Paradox and assess whether current models of linked selection are likely to constrain diversity to this extent. To quantify the discrepancy between pairwise diversity and census population sizes across species, I combine genetic data from 172 metazoan taxa with estimates of census sizes from geographic occurrence data and population densities estimated from body mass. Next, I fit the relationship between previously-published estimates of genomic diversity and these approximate census sizes to quantify Lewontin’s Paradox. While previous across-taxa population genetic studies have avoided accounting for phylogenetic non-independence, I use phylogenetic comparative methods to investigate the diversity census size relationship, estimate phylogenetic signal, and explore how diversity changes along the phylogeny. I consider whether the reduction in diversity predicted by models of recurrent hitchhiking and background selection could explain the observed pattern of diversity across species. Since the impact of linked selection is mediated by recombination map length, I also investigate how map lengths vary with census sizes. I find species with large census sizes have shorter map lengths, leading these species to experience greater reductions in diversity due to linked selection. Even after using high estimates of the strength of sweeps and background selection, I find linked selection likely cannot explain the shortfall between predicted and observed diversity levels across metazoan species. Furthermore, the predicted diversity under linked selection does not fit the observed diversity–census-size relationship, implying that processes other than background selection and recurrent hitchhiking must be limiting diversity.
It seems ridiculous I’ve been using Nigerians as my “African reference” for decades. Most African populations, including Pygmies and Khoisan, have Eurasian admixture from the last 10,000 years. And what about deeper back-to-Africa ancestry? That seems likely and is hinted at in the above paper.
Modern human lineages have a deep history in Africa and the Near East. I think we’re going to have a transformation of our understanding of what happened in these regions in the near future.
Still reading Autumn in the Heavenly Kingdom: China, the West, and the Epic Story of the Taiping Civil War. The narrative is hard for me to keep track of. I wish there was more cultural/social commentary to scaffold the battles and forced marches. Will post on chapter 9 soon.
