Colleen McCullough, R.I.P.

I was aware that Colleen McCullough was ill, so sadly it is no surprise that she has died.

To many McCullough is known for her Masters of Rome series. I particularly think that the first two books in the series, The First Man in Rome and Grass Crown were exceptional. The later novels cover the career of Julius Caesar and his heirs (both Augustus and Antony), which are rather well known to us. In contrast the life and times of Gaius Marius and Lucius Cornelius Sulla are not familiar to many modern people. In fact it is likely that their names would not ring a bell with the vast majority of people due to the decline of the classical education (which was the province of a narrow elite in any case when it was in vogue). But these were significant figures in their time whose influence echoes down the generations. For example, the Marian reforms depicted in The First Man in Rome arguably laid the foundations for the professional Roman legions which were to serve as the basis for the empire of the first few centuries A.D. Caesar nailed the republic’s coffin, but Marius built up much of its superstructure, making the armies loyal to their generals by opening up recruitment to those without other means of support. And Julius Caesar is a less surprising character if you are aware of the precedent of Sulla, whose vicious dictatorship he managed to evade.

Finally, of the peculiar things I recall about Colleen McCullough is that she wrote her massive novels in longhand (or at least her first few ones).

Language (culture) and genes evolve differently

9780226520438Evolutionary process can be modeled in both genes and culture. The former is defined by vertical transmission, while the latter can be vertical and/or horizontal. Unlike heritable biological traits, cultural phenotypes have no discernible units of inheritance in a straightforward fashion which can be easily mapped. But some of the formal models common in evolutionary genetics are also utilized in social evolution and behavioral ecology.

One of the easiest aspects of culture to gain a comprehension of is language. Unlike other cultural phenomena, such as religion, language is clear and distinct. Many believe that in some way it is a deep biological competency, and in fact would put it outside of the domain culture altogether because of its unique role at the center of the propagation of cultural “memes.” A new paper in PNAS explores the correlations of language and genes and geography, A comparison of worldwide phonemic and genetic variation in human populations (open access!). In short, the authors find that the differences in transmission of genes and language result in differences in their patterns of distribution. The correlation between genes and geography scales over the whole world. The more distant a population is from a focal group of interest, the more genetically different it is. In contrast the signal of linguistic affinity (or lack thereof) exhibits spatial limits, beyond which the linear relation decays. Beyond 10,000 kilometers more distant languages are no more dissimilar.

bravoThere are a few issues to unpack here. First, they used a database of phonemes. I have no idea how one would categorize differences using syntactic features, but it strikes me that someone without more familiarity with this field might argue that looking at variation in phonemes is a bit like looking for the key under the lamp. Interestingly the authors found that phoneme similarities transcend language family. In other words, nearness breeds familiarity through horizontal transmission even if the linguistic groups are dissimilar rather than being part of a dialect continuum.

Second, they suggest that one aspect of phonemes and how they differ from genes is that isolated populations exhibit more richness and diversity, rather than less. This illustrates that there are differences between genetic and cultural process. Not only is there a great deal of horizontal transmission, but cultural processes are subject to a greater “mutation” rate, and selection can be much more efficacious. The latter is why group level selection is more mathematically plausible for culture than genes; competing demes can be much more distinct in culture than genes because minimal gene flow can equilibrate biological differences, while biased transmission of culture can result in insulation of different groups from homogenization (e.g., inheriting your cultural traits from your father, rather than your mother, who may have been kidnapped from an enemy tribe).

Finally, in line with the high mutation rate of language the authors reject earlier findings that it follows the same serial founder model detected in a 2005 paper from some of the same authors. I have to jump in here to suggest that we need be careful about assuming that this paper is a robust result upon which we should build up our model. See Towards a new history and geography of human genes informed by ancient DNA for a slight revision. In any case, the results from the language patterns suggest that Europe is the source of human language, using the same framework as genes where there is a decay of diversity from the ancestral homeland. The authors point out that this is a artifact of the fact that phoneme richness is very low in Oceania and South America, and Europe is equally distant from both regions. In other words language is too protean to gain a signal of the “Out of Africa” movement. I do agree with this. It strikes me that those who attempt to reconstruct language as it was 50,000 years ago are grasping for straws. For example, I do not think that we can presume that clicks are ancestral just because the Khoisan have clicks in their language.

The relationship of patterns of genetic variation and cultural variation are essential to elucidate. That is because I believe that we can’t understand patterns of genetic variation without a clear grasp of the common cultural processes by which human genes propagated over time and space. Language is probably the cultural trait that’s lowest down on the tree, so hopefully researchers will keeping picking at it until the big questions get resolved.

Increased de novo mutations for older fathers

Citation: Whole-genome sequencing of quartet families with autism spectrum disorder
Citation: Whole-genome sequencing of quartet families with autism spectrum disorder

The above is from the supplements of Whole-genome sequencing of quartet families with autism spectrum disorder. You can read about the research in The New York Times. I just wanted to highlight the above scatterplot, especially panel A, in the interests of pro-natalist alarmism about older fathers.

Convergent evolution through genetic changes, OK….

Citation: Convergent evolution of the genomes of marine mammals
Citation: Convergent evolution of the genomes of marine mammals

440px-Ichthyosaurios5Most of you have heard of convergent evolution. To some extent it’s often most clear and visible in morphological characteristics which are shaped by the basic physical parameters of the universe around us. Physics is nicely predictable. Bats and birds are subtlety different, but a rough congruence is body plan is evident. More striking are the parallels between dolphins, tuna, and the long extinct Ichthyosaurs. There are a finite manner of ways you can be optimally shaped as a vertebrate if you wish to be fast in the viscous waters of our planet. Living torpedoes need to emulate the sleek lineaments of the torpedo. This is probably where you are wondering what’s so interesting about this, as you read this in the illustrated evolution books you perused as a child. Well, Nature Genetics has a neat new comparative genomic paper out, Convergent evolution of the genomes of marine mammals, which explores on the genomic level what is visible to our naked eyes in terms of macroevolution made flesh in morphological similarities.

It’s an open access paper, and quite short and succinct, so I invite readers to check it out. The methods are straightforward, they sequenced the marine mammal lineages highlighted in red above, and compared them to their sister lineages which had not taken to the oceans, as well as with each other. After comparing regions of the genome they found five genes with evidence of selection across all the parallel lineages, which evolved from very distinct clades of mammals. Some of these genes made sense in terms of their functional relevance for marine organisms. In some cases the substitutions within the gene were distinct. This is to be somewhat expected, as genes are big, and there may be several ways to skin the cat. In contrast in other genes it was the exact same substitution, indicating strong constraint. All good. But then near the end they add this coda:

Our comparison of the genomes of marine mammals has highlighted parallel molecular changes in genes evolving under positive selection and putatively associated with independently evolved, adaptive phenotypic convergence. It has been hypothesized that adaptive evolution may favor a biased subset of the available substitutions, to maximize phenotypic change…and this hypothesis may explain some of our findings of convergent molecular evolution among the marine mammals. However, we also found widespread molecular convergence among the terrestrial sister taxa, suggesting that parallel substitutions might not commonly result in phenotypic convergence. The pleiotropic and often deleterious nature of most mutations may result in the long-term survival of substitutions at a limited number of sites, leaving a signature of molecular convergence within some coding genes. The parallel substitutions in 15 positively selected genes identified in this study likely represent a small proportion of the molecular changes underlying adaptive and convergent phenotypic evolution in marine mammals. Our data therefore indicate that, although convergent phenotypic evolution can result from convergent molecular evolution, these cases are rare, and evolution more frequently makes use of different molecular pathways to reach the same phenotypic outcome.

Basically the expectation here is that obvious convergent evolution is going to drive some similarities on the genomic level. This isn’t too strange an assumption when you note that groups of genes like the Hox show up over and over across many taxa. But the authors also found lots of genomic convergence between terrestrial lineages. This surprised them, because to our naked eye there isn’t any parallelism of form equivalent to what you see among the marine organisms. I think perhaps one aspect we need to consider is that some convergent evolution is in the eye of the beholder. The authors seem to be cryptically pointing to the genotype space being constrained by the genetic correlation matrix, the inability of substitutions to occur because of pleiotropic effects. But what about the possibility that there are similarities between lineages which are not salient in the form of gross morphology? For example, social structure and population density vary between lineages with no particular rhyme and reason (I exaggerate some, but you get the picture when you think of the eusocial mole rat and the eusocial hymenoptera).

Ultimately I think this paper is less important in and of itself than the fact that it sheds light on the possibility that in the near future we’ll get a good sense of the genomic shape of the tree of life, and we’ll have recourse to many high quality genomes all across the tips of the phylogenetic tree. The sorts of comparative methods utilized in this paper also have the good feature of being rather transparent and less abstruse that you often find in population genomic papers.

Science is different from religion

51u-xXl9qUL._SY344_BO1,204,203,200_The Atlantic has a long piece up which basically consists of a list of the usual objections to DNA testing from some Native American groups and individuals (which can be generalized to any indigenous group), Genetic Testing and Tribal Identity: Why many Native Americans have concerns about DNA kits like 23andme. There’s the standard stuff about how Native Americans believe archaeological remains are sacred, etc., and how that conflicts with scientific enterprises. The necessary mention of NAGPRA and such. But this quote was rather “interesting”:

“We know who we are as a people, as an indigenous people, why would we be so interested in where scientists think our genetic ancestors came from?” asks Kim Tallbear, a researcher at the University of Texas at Austin, the author of Native American DNA: Tribal Belonging and the False Promise of Genetic Science, and a member of the Sisseton-Wahpeton Oyate tribe.

Tallbear says that from her perspective, researchers offering to tell tribes where they’re from doesn’t look any different than the Christians who came in to tell them what their religion should be. “Those look like very similarly invasive projects to us,” she said. Tribes haven’t forgotten the history of scientists who gathered native skulls to prove that native people were less intelligent, and thus less entitled to the land they lived on than the white settlers. To them, these genetic questions of origin look pretty similar.

Tallbear explains that to be able to do ethical genetic research on native people in the United States, you need to understand their history. “You have to know something about the history, and about 20th century Native American policy, and how the U.S. as a colonial power dispersed native people from their historic homelands into urban areas and into reservations, how different groups have put tribes together on reservations who never lived together before. You have to know about about relocation and post-World War II politics. If you don’t understand that you can’t begin to ask informed questions about the genetics of Native Americans.”

Kim Tallbear has an academic page. Here’s a sample:

Indigenous, feminist, and queer theory approaches to critical “animal studies” and new materialisms

I have also recently begun to theorize in the area of indigenous, feminist, and queer theory approaches to animal studies and new materialisms. Last year, I co-organized with the Science, Technology, and Society Center at UC Berkeley a symposium on indigenous and other new approaches to animal studies. I was also part of another UC Berkeley symposium last year on New Materialisms where I did a talk on the role of indigenous thought. Both symposia helped mark a space for the role of indigenous thought in these related and burgeoning areas of contemporary social theory and new ethnographic practices.The recent move to “multi-species ethnography” applies anthropological approaches to studying humans and their relations with nonhumans–beings such as dogs, bears, cattle, monkeys, bees, mushrooms, and microorganisms. Such work is both methodologically and ethically innovative in that it highlights how organisms’ livelihoods are co-constituted with cultural, political, and economic forces.

Let’s not beat around the bush here, Native Americans and the government and culture of the United States have a fraught relationship. That is true. But today genetics has pretty much zero relevance to the various political debates and arguments. Issues like tribal membership are determined by the cut & thrust of politics, not genomics. Frankly, these issues are too important to leave to genetics. The possible consequences of genetics are always vague future possibilities. For people who don’t care about abstract genetic questions though even a vanishingly small probability that genetics might impact their concerns is too much of a risk, so naturally they wish to squelch it. And contrary to the implication that Tallbear makes, most scientists who work on Native American genomics don’t do so because of a deep interest in overturning the religious traditions of Native Americans, but because they are interested in the human story, of which Native Americans are an essential part. Rather than ethnic particularism the motives of scientists on the whole are those of universalist humanism.

So one can understand why political activists might balk at the inquiries of geneticists, as universalist humanism often causes problems for those engaged in the great game of ethnic particularism. But what about the academics who lend their voice in support of the latter? As far as Kim Tallbear’s “scholarship” (I hope I’m using quotations appropriately here) it resembles what I saw in Genetics and the Unsettled Past: The Collision of DNA, Race, and History. Basically an exercise in lexical obfuscation in the service of nebulous political aims, but clearly with direct consequences for the careers of a small set of academics who operate in an area where politics and activism blend seamlessly into their professional lives and their reputation among their peer groups.

Many of the assertions that Tallbear and company make about science are not totally unreasonable on the face of it. Science is a human enterprise, and scientists bring their own biases, ideologies, and interests into the execution of their endeavours. To some extent science is subjective, insofar as humans are making the judgements. But when you see where these practitioners of science studies take their project, you understand that they’re basically crazy. That is why people like Steve Fuller end up making apologia for Intelligent Design. And that is why Kim Tallbear can boldly analogize scientists to Christian missionaries. There’s simply no acknowledgement of something I like to call objective reality, so they go straight for the most provocative rhetorical tacks to hammer home their polemic.

Higher_SuperstitionHere is an indisputable fact: science is not religion, and the two are very different enterprises. If you don’t accede to this distinction, you have just lost all touch with the empirical world. It is no surprise that Phillip E. Johnson, the doyen of the Intelligent Design movement, has acknowledged a debt to critical theory. The flight from empiricism is exactly what has occurred to many scholars within science studies, probably because that’s where the career incentives are. Instead of actually pursuing a sociology of science*, they just slot science into the theoretical framework of critical theory, postcolonial studies, Marxist analysis, etc. etc., and generate out their truths deduced from a priori in a stream of prolix papers and prose whose primary purpose is to be read by a few other fellow travellers.

Kim Tallbear is really no different form Steve Fuller insofar as she’s acting as an apologist for Creationism, though a different sort from the Christian one. If Christians made the same arguments as Native American spokespersons in relation to these topics there’s no doubt that scientists would react caustically. But Native Americans are a disadvantaged group, and so the skeptical acid which scientists normally reserve for pre-scientific beliefs is withheld in this case (among social justic types this would be “punching down,” though in this case I think some punching is justified). That’s an empirical sociological fact. But, that doesn’t negate the reality that the scientists are right, and indigenous religious traditions which contradict the idea of migration via Beringia are wrong (as are some of the naive ideas about Native Americans being of the lost tribes of Israel, which was a common belief in 19th century America, and has come down in an evolved form within the Mormon religion). And I don’t mean “right” and “wrong.” I mean right and wrong. Like 0 and 1. Black and white. That’s because positivist science illustrates that social and linguistic ideological construction of the world around us runs up against the boundaries of the fact that the world has patterned and structured order which runs in contravention of human intuitions and biases. Most academics who are skeptical of the “objective” “truth” “claims” of “science” also agree with this fact when they have to put their choices where they mouth is. If they’re diagnosed with “cancer” they won’t put chemotherapy in quotations or demand the services of a tribal shaman. It’s going to be the best science for them and their family. That’s not just a theory, that’s a fact.

* Some scholars do do this, but it’s hard.

Addendum: An interesting sidenote is that the solicitation of many American scientists toward indigenous people in North America is itself an ideological orientation. As an example, many Asian Indians are not very happy with the latest results coming out of human genetics because it conflicts with their religious-social beliefs, but generally this is not much on the radar of researchers who are opining about the genetic history of these billion or so people.

The Parsis are about 25% South Asian genetically


parsi2In the comments below I made the comment that the Parsi people of India, who reputedly arrived in India ~1000 years ago from Iran, are about 25 percent South Asian. By this, I mean that their ancestry is about 75 percent Iranian (presumably Persian), with 25 percent admixture from South Asian populations amongst whom they lived. But my feeling about this was vague, and I decided to check the scientific literature. Unfortunately there hasn’t been a lot of work done in this area with cutting edge genomics. But a cursory examination shows that there’s been substantial migration of Indian women into the Parsi lineage via the mtDNA. In the figure to the right you see that “PA”, the Parsis, have a lot of “South Asian” mtDNA lineages compared to the Iranian groups. This mostly consists of South Asian branches of haplogroup M. It jumps out to you immediately when looking at the haplotypes that the Parsis carry on their mtDNA. I found less on the Y chromosomes, which are less informative in differentiated South Asians from Iranians in any case (the mtDNA difference is much greater between these two regions), but what I did find is that Parsis can be modeled as 100% Iranian on their paternal lineages. This is probably an exaggeration, but as a stylized fact I think it gets to the heart of the matter.

But what would really be useful are autosomal results. Those were hard to find. Noah Rosenberg’s 2006 paper on Indian genetic differentiation using microsatellites did have a Parsi sample. If you look at the results the Parsi do seem South Asian, roughly equivalent to Pathans, an Iranian speaking group in Pakistan which has strong South Asian affinities. But the sample set does not include any Iranian groups from Iran proper, but rather Middle Eastern groups from the Arab world or the Caucasus. Without such a reference population it is hard to gauge Parsi relatedness.

There was one last hope. Harappa DNA has been collecting results for many years now, and I was hoping that there was a Parsi in the sample. There was, just one. I took the Parsi and compared this individual to various Iranian and a few select Indian groups. Here are the admixture results (edited to show only the relevant ancestral clusters):

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Open Thread, 1/25/2015

9780307823069_p0_v1_s260x420My intention was to read Ian Morris’ War! What Is It Good For?, but I’ve decided on Jonathan Spence’s Emperor of China: Self-Portrait of K’ang-Hsi. I’ve had this book for about seven years, and haven’t gotten to it, but now is a good time since I’ll be tackling Marcus Aurelius: A Life, and Meditations. The relationship between these two topics should be obvious to most readers with some familiarity with history.51NPyQMF0jLSimultaneous to this I’m reading The Northern Crusades on the Kindle. I got about 25% of the way through this book at some point, but had to set it aside. But the history of the Baltic has always been fascinating to me, and I think it’s an interesting topic. Most people seem unaware that the Crusades occurred in northeast Europe as well as the Levant, and that they lasted in active form longer in the north than in the Middle East.

I’ve been considering the role of specialization in science recently. Obviously I’m interested in genetics, and that has sharply constrained by knowledge of the literature. Even within genetics I’m fixated on the topics of evolutionary genomics, with a focus on humans and other mammals. When I was younger my interests were far more catholic, though I don’t know what I can do about this evolution in my focus at this point. We all go through phases, and perhaps in the future can I branch out again.

Finally, can readers people stop leaving comments with the handle “anon” or “anonymous.” I don’t mind if you have these terms in the name, but it gets very difficult to follow people if there are six or seven different individuals who go by “anon.”

The Houthi are the most like Sunnis of the Shia

The New York Times has a piece within the title Experts See Signs of Moderation Despite Houthis’ Harsh Slogans. It mulls over the fact that the Houthi rebels, who are rapidly becoming the establishment, brandish anti-American and anti-Israeli slogans, and are clearly getting Iranian money. The piece mentions that the Houthi rebels are Zaydi, which is a branch of Shia Islam. But to me the article tip-toes around a somewhat important point about Zaydi Shia Islam: it is usually considered the most “Sunni-like” of all the Shia sects. One of the aspects of John Walker Lindh’s biography was that when he was in Yemen he was offended that Sunni and Shia prayed in the same mosques on occasion. This reflects the fact that Zaydi are not as deviated in practice from Sunni Muslims as other Shia. In the article there is the question of an analogy to Hezbollah:

“The Houthis are not Hezbollah,” said Charles Schmitz, an expert on the group and a professor at Towson University, referring to the Iranian-supported group that dominates Lebanon and is actively fighting on behalf of President Bashar al-Assad in Syria. “They are domestic, homegrown, and have very deep roots in Yemen, going back thousands of years.”

All true. But I think it needs to be emphasized that Hezbollah espouses the same Twelve Shia religion as Iran, and the connections between these two groups is historically very deep. The conversion of Iran to Twelver Shia Islam occurred in the 16th century under the direction of ulema imported from southern Lebanon, basically the same group which has supported the rise of Hezbollah. The reciporcal exchange of ulema between this region and Iran has continued down to the present day (see The Shia Revival by Vali Nasr). Any attempt to connect the Houthi to Iran has to be careful, emphasizing the situational aspect of this relationship when compared to Hezbollah. Because of Hezbollah’s ideological and historical identity with the Iranian religious order it is hard to ever imagine a scenario where it acts counter to Iranian interests. This is not the case with other groups which are allied with Iran, such as the Assad regime, whose Alawite sect is only nominally Twelver (due to some political machinations in the 1970s), or the Houthi, whose Zaydi sect was the dominant one within Shia Islam for many hundreds of years before the conversion of Iran to the Twelver set.

Western liberals are the WEIRDist

41DV5KYNJALA friend passed me this ScienceDaily press release, American liberals and conservatives think as if from different cultures. I suspected that Jon Haidt was on the paper, and I was right, Liberals Think More Analytically (More “WEIRD”) Than Conservatives. Reading the paper the major finding seems to be that Western social liberals, and especially libertarians, exhibit the tendencies which have been defined as “WEIRD”: Western, educated, industrialized, rich, and democratic. In contrast, social conservatives in the West are less WEIRD, and tend to resemble non-Western cultures in cognitive style.

The way that this paper dichotomizes the classes is that the WEIRD tends to be more “analytic” and non-WEIRD more “holistic.” The terminology here is often freighted, and I’be cautious about overemphasizing that aspect. Rather, the key here is that in terms of traits you see a pattern where Western liberals are to a great extent the tail of a particular distribution of mental styles. To illustrate the analytic style of reasoning Joshua Greene, the author of Moral Tribes: Emotion, Reason, and the Gap Between Us and Them, has argued that incest taboos are based on disgust and reflex, rather than reason (or, the reasons are rationalizations). And, that this is clearly from his perspective not a good thing. That is the classic WEIRD tendency; to decompose the broader issue into its parts, and reach logical conclusions, even if they seem absurd or repulsive, and embrace them. Brian Williams is also WEIRD. Very WEIRD.

1361104223In the above paper they use samples of college students at University of Virginia, those who participated in the moral foundations survey, and a few thousand Chinese students, to test their model. Though the correlations in most cases were modest (e.g., on the order of 0.2 to 0.4), it seems clear from their data that a left-right social orientation can map mapped onto differences in analytic vs. holistic thinking across cultures, and also reflect differences between cultures. Chinese college students raised in urban areas were more analytic if socially liberal. Western college students were more holistic if socially conservative.

I don’t think any of this is going to shock or surprise anyone. Rather, the interesting part to me is how easily it maps onto pattern discerned by the psychological Richard Nisbett, and reported in his book The Geographic of Thought: How Asians and Westerners Think Differently…and Why. Nisbett reported a pattern which in today’s language would have a continuum of WEIRDness like so: Anglosphere & Norden > Continental Europe > rest of the world. These data in that framework suggests that even within the Anglosphere, which is dominated by WEIRD thought, there are a large reservoir of people who reject that paradigm in their daily life. In addition, the correlation with length of time post-industrial, as well as the fact that the tendencies toward WEIRDness are now cropping up in East Asia as well, suggest that in some ways a Whiggish model is broadly correct. Nisbett and Haidt’s group both report that it isn’t particularly difficult to prime individuals to switch from one mode of cognitive style to another.

Finally, many social liberals look at social conservatives as being backward, and in need of being “educated” and “ignorant.” There’s some descriptive truth in this, insofar as there’s a fair amount of evidence that social conservatism is negatively correlated with intelligence and education. But, one can also look at social conservatives as a different culture, as simply not WEIRD. This puts modern social liberals in somewhat of a bind if they are multicultural, because perhaps they are now enjoined to extend their tolerance of other cultures to social conservatives? OK, forget about that.

The search for Indo-Europeans in comment sections

horsewheellanguageDavid Reich and Nick Patterson come down in favor of the steppe as the ur-heimat of the Indo-Europeans, at least those who migrated into Europe, in a recent abstract:

We generated genome-wide data from 65 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of about 390,000 single nucleotide polymorphisms. This strategy decreases the sequencing required to obtain genome-wide data from ancient DNA samples by around 1000-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that in western Europe, the farmers of both Germany and Spain >7,000 years ago were descended from a common ancestral stock. These farmers did not replace the earlier hunter-gatherers, but continued to mix with them, leading to a resurgence of hunter-gatherer ancestry in both Germany and Spain ~1,000-2,000 years later. In eastern Europe, the hunter-gatherers of Russia >7,000 years ago were distinct from those of the west, having an increased affinity to a ~24,000 year old individual from Siberia, but this affinity was reduced by ~5,000 years ago in the Yamnaya steppe pastoralists because of admixture with a population of Near Eastern ancestry. Western and Eastern Europe collided ~4,500 years ago with the appearance of the Corded Ware people in Central Europe, who derived at least two thirds of their ancestry from an eastern population closely related to the Yamnaya. The evidence for mass migration into Europe thousands of years after the arrival of agriculture, in combination with linguistic and archaeological data, makes a compelling case for the steppe as a proximate source for the spread of Indo-European languages into Europe.

This is broadly the same data which Iosif Lazaridis presented at ASHG 2014. So this itself is not new. But what I would like to draw your attention to are two posts over at Eurogenes, Ancient DNA points to the Eurasian steppe as a proximate source for Indo-European migrations into Europe, and Yamnaya genomes are a 50/50 mix of eastern Euro foragers and something else ANE-rich. Nick Patterson actually weighed in over in the comment thread for the first post. A comment in the second post was especially amusing:

Over 400 comments on an abstract? You may need to start a forum when the actual paper is released, David.

insearchofYes, there were over 400 comments on the first post. It shows you how passionate people get about this issue. Some of the associations within this field are of a racialist nature. The Journal of Indo-European Studies was founded by Roger Pearson, though today it is edited by the respectable J. P. Mallory. This is not to say that all of those enthusiastic about this topic are quite so “out there,” but it’s quite emotional.

Until the paper itself comes out I suggest readers bone up on the archaeology, because there’s a wealth of that out there already. From what I recall the Samara samples were form David Anthony, and his The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World is basically required reading in my opinion if you are interested in this issue. Also, Mallory’s older In Search of Indo-Europeans is probably worth reading as well. We live in interesting times indeed!