Norway Offers Migrants a Lesson: “No Rapin’!”

The New York Times has a very long and detailed article titled Norway Offers Migrants a Lesson in How to Treat Women. Here’s the primary issue:

Henry Ove Berg, who was Stavanger’s police chief during the spike in rape cases, said he supported providing migrants sex education because “people from some parts of the world have never seen a girl in a miniskirt, only in a burqa.” When they get to Norway, he added, “something happens in their heads.”

The statistics are pretty straightforward, and some are outlined in the article. This is a robust and replicated dynamic in Scandinavia; people of “migrant background” are over-represented in rape statistics. It’s an open secret, in that when push come to shove the authorities tend to make excuses rather than lying about it. Though Scandinavians maintain public norms of political correctness, their revealed preferences in terms of self-segregation and ubiquitous “white flight”, illustrate that everyone knows the reality even if they don’t address it out of politic.

Migrants themselves can often be quite frank and astute observers of cross-cultural differences:

“Men have weaknesses and when they see someone smiling it is difficult to control,” Mr. Kelifa said, explaining that in his own country, Eritrea, “if someone wants a lady he can just take her and he will not be punished,” at least not by the police.

Norway, he said, treats women differently. “They can do any job from prime minister to truck driver and have the right to relax” in bars or on the street without being bothered, he added.

Mr. Isdal, the Stavanger psychologist, said refugees, particularly those traumatized by war, represent a “risk group” that is not predestined to violent crime but that does need help to cope with a new and alien environment.

Unfortunately it’s not surprising that the “professionals” are making excuses for these men. All of a sudden males, who are sometimes portrayed in feminist literature as “natural born rapists,” become traumatized by war and no longer responsible for their actions (or at least not as culpable). This turns “victim blaming” on its head. But in a world where white males are the font of all evil non-white males are denied any agency (i.e., conflict and trauma can always be blamed on Western nations somehow).

The reality is that the attitudes expressed by Mr. Kelifa are not that atypical over recent human history. What’s atypical is the sort of gender egalitarianism which is normative in Scandinavia, and to a lesser extent in much of the West and other parts of the developed and developing world. My own suspicion is that in small hunter-gatherer bands the worry of violent rape at the hands of strangers was not a concern, because there were no strangers, and women were often in the close presence of males who were either relatives, or males with whom they were bonded with (in the case of partilocal societies). Norms of extreme sex segregation and minute physical control of women by groups of men probably arose in agricultural societies where contact with strangers became more common, and powerful patriarchies became organized and standardized.

Individualistic Western norms, which are slowly spreading throughout the world, are in some ways a reversion back to norms of the hunter-gatherer period. What we are seeing today is a slow unwinding of the institutional and social scaffolds that arose as cultural adaptations during the long period between the Pleistocene and modernity, when what had been hunter-gatherer clans were thrown together without innate cognitive tools at the scale of the individual to enable social cohesion. But the older cultural norms persist in many contexts even in the West. See the video below, which perhaps should be adapted for migrants….

Open Thread, 12/20/2015

51C57PXe4wL._SX324_BO1,204,203,200_An informational note, if you’re on Twitter, you might want to follow me at Second, I haven’t had the time to contribute much content to the net besides this blog recently, but in general it is optimal to follow my total content feed, at, rather than various blogs and publications which I contribute to (I’m going to branch out a bit more into more traditional writing again this year, time permitting). I automatically push author archives at other sites to that location, though I’d probably put a note into an open thread in a given week here.

I can’t say enough how much I’m enjoying Stanislas Dehaene’s Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts. This the third book by this author I’ve read. The Number Sense 15 years ago, and Reading in the Brain earlier this year. Dehaene can write, and, he’s a practicing cognitive neuroscience, and it shows. I’d recommend both.

13426114TheI think I’m going to push Dan Ariely’s The Honest Truth About Dishonesty: How We Lie to Everyone–Especially Ourselves up in my stack. Around ~2008 and for a few years later Ariely seemed to be everywhere. I read Predictably Irrational during that time, and immediately bought Ariely’s The Honest Truth About Dishonesty when it came out. But it strikes me that the interest in bounded rationality and behavioral economics has waned a bit. Also, I recall that The Honest Truth About Dishonesty had a blurb from Jonah Lehrer, right about at the time that his career and life was in the early stages of meltdown. Really bad timing.

The fact that someone could state that this fact is “trivia“, at a time when women are being integrated more fully into combat positions which might require physical strength, is interesting. Sex differences in morphology, physiology, and psychology, have huge implications. But there are certain sectors who deny them, or, barring that simply claim that the differences are trivial. I don’t think they are.

The American Heart Association seems totally corrupt. Their recommendations seem to exhibit an extreme stickiness, refusing to be updated to the present.

This piece in The Atlantic about incorrect or misleading results due to genetic testing is interesting. But, it needs to be kept in perspective. Consider the past 50 years of nutritional “science,” which have shaped the lives of hundreds of millions of people. Or educational and policy fads, such as whole language learning and massive freeways which cut through the heart of cities, that have wrought havoc on untold millions. Genetics isn’t special, and, nor particularly worrisome.

It seems likely in the near future Facebook and Google will be implementing massive genome-wide association studies, simply by intersecting their customer data with genomes.

I am aware that many of you have a high self-regard for your intelligence. Since you are intelligent you are probably aware that I don’t share your opinion in relation to yourself. When I ran Gene Expression as a group blog we used to have a word for people who left comments: we called them “animals.” Obviously this was simply the median commenter. Not all of them. If some of you are surprised or annoyed that I’m dismissive and insulting to you on Twitter or in the comments do understand that my prior expectation is that you probably don’t have much to say that I’d be interested in, and I may be annoyed that you think you are worth expending my time on. You could have the same prior about me, but if that’s the case I invite you not to read me, as I’m not reading you (it is notable that over the years I’m noticed that the people who have their own blogs are the least annoying and obnoxious in their self-regard, and stick to talking about what they know).

The number of people who read this blog regularly and who follow me on Twitter is simply well beyond Dunbar’s number by any definition, so I’m not able to “put a face” on many or most. Additionally, despite the current populist and demotic dispensation I think humans differ a great deal in their characteristics. I’m not interested in watching average looking leading ladies in my films (sorry Maggie Gyllenhaal), nor am I interested in having intellectual exchanges with average intelligence people (in “real life” I am very open to talking about sports, weather, and sex, with normals). Also, I have a long memory. If you talk shit about me on other blogs (like you dearieme) and continue to comment here, I’ll probably ban you because you’re just being a shady dick. Or, if you psychoanalyze me when you don’t know much about me (like you Ikram, if you don’t remember email me and I’ll tell you the incident that I remember) or my motivations (like you aeolius) I’m going to remember your presumption and be keen to delete/ban you in the future.

N of Everyone has posted my commentary in Genome Biology from last year, Dragging scientific publishing into the 21st century. I’m exciting that they’re moving along with their project. Preprints are great, but we need more tools and platforms for post-publication review. Except to hear more from them in the coming year.

I’m am not following politics too closely. Definitely out of sync with my Twitter feed. But really nothing matters until the nominations.

Alice Dreger has balls writing Gender Mad, which is going to invite accusations of her being a TERF. By balls, I don’t mean in the literal sense. For the record, I am confused by the arguments of the modern mainstream trans movement, as they seem to flip between radical social construction (i.e., we all get to choose our gender in a very conscious manner conditional on cultural norms) and implicit biological essentialism (e.g., “I was always a female brain in a male body”). Hopefully we will hit a happy medium were trans people can be physically safe and given some tolerance and accommodation, without accepting the idea that cis-heternomativity and trans identities are totally equivalent (there will always be many more of us than them!).

I had a short exchange on Twitter with Rosalind Arden about statistical education. Would it benefit people? My own sentiment is to say yes. But, I’m also deeply cynical at this point. It strikes me that many people use statistics or knowledge about specific topics to obfuscate as much as to illuminate.

ISIS is steadily gaining strength in another Middle Eastern country while everyone looks the other way. This is going to sound weird, but this reminds me of 2006, and the rivalry between Facebook and MySpace. Yes, al Qaeda in the Arabian peninsula is dominant in Yemen today. But the long term trajectory seems pretty clear. ISIS is going to win this competition, just like Nintendo edged out Atari, or the iPhone destroyed the BlackBerry.

CDS Appropriates Asian Dishes, Students Say. You should read the Oberlin story on cultural appropriation of cuisine just for fun. The weirdest quote is from a Chinese student who doesn’t understand that General Tso’s chicken wasn’t “appropriated” from China, but invented in the United States, suggesting that she was familiar with a dish that was imported (“appropriated” and modified) back to parts of China from the United States.

51VWcX2sJDL._SX327_BO1,204,203,200_I watched the new Star Wars film. It was good.

Very excited to spend Christmas with my kids. They’re getting old enough to look forward to holidays and appreciate presents.

Excited by all the science which is being published in 2016. Papers in review that I’ll blog, and papers I’ve heard long rumored to finally hit the presses. I should be analyzing some very interesting data for my Ph.D. project.

The Scholars Stage blog is very good. Check it out if you haven’t.

A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China. A very weird paper. Not definitive.But the history of our species looks curious indeed.

One Direction is so young, and been around so long, that some of these teen idols are hard to recognize, as they’re changed styles and gone from being in their middle teens to early 20s. I find it really strange.

“Pulling a chipotle” on our culture

bobosAuthenticity is a big deal. But it comes at a price, and we might finally be near the point where a backlash ensues. Perhaps. Paul Bloom outlined the evolutionary and cognitive roots of this preference in Descartes’ Baby, but perhaps more illuminating for most is David Brooks’ Bobos in Paradise, which prefigured Stuff White People Like. Though a quest for authenticity is generally a feature of the cultural Left, Rod Dreher in Crunchy Cons made the case that this lifestyle is an aspiration of the urbane and intellectual more generally. To a great extent authenticity has become a consumption good, a way in which the upper middle class can expend their discretionary income.

Often it is harmless, but sometimes it is not. And sometimes it attracts opportunists. Today Quartz has a piece out, How the Mast Brothers fooled the world into paying $10 a bar for crappy hipster chocolate. The story is simple: entrepenurial “bros” grow beards and transform into “hipsters,” and create a story of artisanal chocolateering which is designed to allow them to mark up retail prices, while making recourse to mass economies of scale and modern know-how and tech to reduce their inputs. Basically, these guys are scamming the public by selling the image of authenticity, but under false of pretenses. This is a general issue, not limited to Brooklyn. The show Duck Dynasty morphed an upper middle class conservative Southern white family into rougher and more earthy “rednecks.” All the way to the bank.

But this impulse imposes costs. There have been dozens of stories like this over the past few weeks: Was Chipotle too busy avoiding the fake dangers of GMOs to focus on actual food safety? There’s a lot of schadenfreude at work here. Chipotle made a big show about avoiding GMOs, in part on grounds of safety, though there is no evidence that they’re unsafe. And yet Chipotle did make a commitment to fresh ingredients that are made by hand, and admit freely that this increases the risk of food poisoning (in short, machines don’t have to wash their hands after they go to the bathroom!). This authentic “slower” process, and fresh locally sourced non-GMO produce inputs, allowed Chipotle to mask the reality that their items are often very high in calories, with the same supposed downsides as conventional fast food. In other words, it was great capitalism. But now we’re coming up to the reality that there’s a reason that mass production, standardization, and mechanization, were adopted in the first half of the 20th century in the first place. Avoiding vaccines and antibiotics are also “authentic.”

Is Sichuan cuisine the best there ever was?

This is what I ate on Tuesday night

I am of the generation of people who purchase experiences, rather than things. OK, well, at least my bias is toward experiences, rather than things. For several years now I have had an obsession with Sichuan cuisine. I was introduced to one particular restaurant in a major American city by a Chinese (Fujian-born and bred) coworker, and now every time I am in that particular city on business I make a sojourn to that restaurant. In my fever dreams I fantasize about synthesizing Sichuan and Korean, two of my favorites.

My question: is East Asian cuisine, and in particular Chinese, simply better in some Platonic sense? If so, what are you favorite restaurants? If not, what are your favorite restaurants?

I’m trying a new Sichuan place tomorrow which has great Yelp reviews. Hope I’m not disappointed….

Most people gain from resistance training

The_Sports_Gene_Book_Cover_2013Can everyone get stronger, bigger, and more fit, from resistance training? Well, not literally everyone, but the vast majority of people. In the comments Jason Malloy made a reference to David Epstein’s The Sports Gene, where there is mention of people who don’t respond to strength (or endurance) training. I don’t doubt such people exist; I just doubt that they’re that numerous.

As it happens I have a copy of The Sports Gene. I haven’t read it because I have a lot to read (Consciousness and the Brain is as good as some readers reported!), and frankly the marginal return for me toward reading books on genetics as opposed to papers is often not that much. But I skimmed through The Sports Gene just now, and I have to say it’s very good. There’s a chapter on sex differences and it reports all the results I’ve been blogging about with amazement recently. If I’d read Epstein’s book I wouldn’t have been quite so surprised. He reports that men have 80 percent more upper body muscle mass, about 50 percent more lower body muscle mass, that our punches are twice as powerful, and that the average man has more upper body strength than 997 out of 1000 women drawn at random.

Screenshot from 2015-12-17 23:09:28But I was interested about the research Malloy pointed to. Probably the best paper was Variability in Muscle Size and Strength Gain after Unilateral Resistance Training. My intuition that you need to be pathological to exhibit no gains from strength training is probably too strong. As the distribution to the right shows ~5-10% of men and women seem to show no gains in muscle mass in the bicep after 3 months of training. The sample size was 585, and included men and women. But, the modal gain was ~25% for men and ~20% for women.

Screenshot from 2015-12-17 23:15:12Out of 585 subjects, 232 subjects showed an increase in muscle size of between 15 and 25%. Ten subjects gained over 40%, while 36 subjects gained less than 5%. The distribution of gains in strength on the bicep curl motion were somewhat more erratic, but again, most men and women gained strength. For strength 232 subjects showed an increase of between 40 and 60%. Out of 585, 36 subjects gained over 100%, while 12 subjects gained less than 5%. Interestingly, women gained more in relative terms in relation to strength than men did.

In short, these results indicate that there’s about a 90% chance that you’ll see appreciable gains in size and strength with resistance training. The results will vary, but the average person seems to gain about 20 to 25 percent in mass. My on and off trainer (some postdocs have interesting past careers) always tells me to focus on myself and not all the jacked up monsters in the gym, but now that I have a sense of the average returns to normal amounts of resistance training it strikes me I’m about average in relation to gains in size and strength in the upper body. If this is genetic then it’s not surprising, as both my brothers have had periods of lifting (one of them pretty regularly through his life) and gain at minimum normal amounts of muscle mass.

An End to Down Syndrome?

bianchi.2x299The figure to the left is from a piece in The MIT Technology Review, A Change of Mind. It profiles Diana Bianchi, a researcher who was involved in pioneering tests to discover Down Syndrome early in utero, but now is working on curing the disease. Here is a delicate aspect:

… She says that early testing will lead to the first treatments for Down syndrome. With the ability to routinely detect the syndrome as early as 10 weeks of pregnancy, she says, the tests are creating the chance to develop drugs that address cognitive deficits in the womb. “Plenty of people think that their children with Down syndrome are perfect the way they are,” says Bianchi. “But there are also plenty of people who, if given the choice, would want to attempt to treat their children.” Critics of testing “don’t know the complete picture,” she says. “They don’t realize there is another half to the equation.”

The idea that children with Down Syndrome are “perfect” the way they are is a testament to an aspect of our society today which transcends ideology and subculture. The way we are is asserted to be the way we ought to be. We are all beautiful, we are all talented, we are all equal. The reality is that this is simply not true. Humans are very diverse. In some cases that diversity means that some have more than others. The intelligent, the beautiful, and the healthy, have what those without would like to have. In some cases the traits may seem trivial. Taller men have an easier time finding a sexual partner, obtaining a leadership position, and earn more over their lifetime. Height may seem a superficial trait, but has enormous consequences over one’s life.

Diana Bianchi is now trying to fix the developmental abnormalities, often triggered by the non-wild type karyotype, of individuals with Down Syndrome. But the reporting in this piece suggests many in the Down Syndrome community are ambivalent about a cure, though some are supportive. After all, a “fix” implies a problem, which many will not admit. My own question is why pro-life organizations and individuals don’t fund Bianchi’s research to the hilt?

Open Thread, 12/13/2015

51C57PXe4wL._SX324_BO1,204,203,200_Finished Meditations. Important to remember that a man I admire to some extent could note that it was meritorious that he did not focus excessively on natural science, when that is to a large extent my raison d’etre. Now reading Stanislas Dehaene’s Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts. This is part of my conscious attempt to refresh my familiarity with domains of science outside of genetics, a major oversight since I began graduate school. At some point I’ll branch out to physics, as Sean Carroll’s From Eternity to Here is in my stack, but I’m always worried that I’m really missing most of the essential aspects of a science the further I go out from my own area of core competency.

I will be traveling a bit before Christmas. Today I am in Austin, meeting up with a few people, mostly hanging around downtown.

710R2Y7ANZLCamille Paglia has resurfaced to attack Taylor Swift and her “obnoxious Nazi Barbie routine.” I can still remember seeing her speak extemporaneously on C-SPAN circa 1994. I was captivated, and pretty much immediately read Sexual Personae and Vamps & Tramps. Honestly I am not sure if I agree with her argument, but she was awfully entertaining, and skewered the people who I already instinctively detested. In hindsight her ethnic animus toward icy cold blonde women grates on me, but at least she’s transparent and honest about this bias. Sexual Personae is heavy going from what I recall, but Vamps & Tramps is an easy and entertaining read. Recommended if you aren’t familiar with her oeuvre.

Nearly two years ago I read an article in Rolling Stone, Love and Death In the House of Prayer. The piece strongly implied that Tyler Deaton, a gay man (in that his sexual attraction is toward his own sex) who led an evangelical Christian group was somehow involved in the death of his wife. More precisely, he may have precipitated her murder by a follower. I was curious what happened to this case…and I stumbled onto the original Rolling Stone piece. There is now an update which totally exculpates Deaton of any wrongdoing, and admits that his wife almost certainly committed suicide. So for years people were led to assume that Tyler Deaton was involved in a murder, which resulted in an inability to obtain work. Now, it turns out that he’s totally innocent, not just legally, but perhaps ethically and morally as well. I invite you to read the Rolling Stone update, because I suspect very few of those who originally read the story will do so.

There’s a lot of hatred on my Twitter toward Abigail Fisher from liberals who I follow. That’s fine I suppose, but it is sad that many liberals now think that any opposition to affirmative action is ipso facto evidence of racist intent. Yes, people tend to be ideologically insulated, both on the Left and Right, but at some point it will come back and bite people in the ass. Abigail Fisher isn’t the world’s worst monster; she happens to represent a substantial proportion of the electorate who hold different policy positions than the regnant liberal dispensation.

The New York Times has an op-ed about Canada welcoming refugees. Look, even Germany and Sweden’s efforts are drops in the ocean. I have a friend who works between Turkey and the United States. He has seen the impact of a mass inflow of refugees on the streets of Ankara, and it’s not a pretty picture. If humanitarianism is the ultimate end, then the gusher of money needs to be unleashed on the millions of refugees in Turkey and Lebanon. The ones who make it to the West tend to be more privileged on average for various reasons. Also, it should be noted that the lauded Canadian refugee policy is discriminatory; I happen to agree with discrimination in this case, but I’m not one to make a big fuss in general about filters of this sort. But some might ask why we’re discriminating. It’s 2015.

Pew has lots of data on opinions of Muslims. One of the major problems that Left and Right in the West have is that they have their own simple stylized conceptions, and don’t engage with the data. For example, there isn’t a dichotomy between moderate and extremist/radical/jihadi Muslims. Islam is a diverse religion with many factions, sects, and positions along the spectrum. On the whole radical extremists are a minority, but a non-trivial one. Additionally, a substantial number of Muslims are not violent radicals, but harbor views broadly in sympathy with their aims. Then, there is the genuinely liberal minority, not in relation to their view of Islam as much as their attitude toward the role of religion in a polity and the balance between collective and individual rights.

I plan to be at the spring Evolution Meeting in Austin this year. Very excited.

Thanks, re: health and fitness

9781623364182A shout out to the readers who responded below. Many interesting comments, and I learned a lot. It’s a thread that I have actually reread several times. For what it’s worth, I got a copy of The Lean Muscle Diet, mostly because I want to start learning more about the topic, not because I’m taking it as gospel. But one thing I’ve started doing immediately was cut back on the running on frequency, but increase intensity/pace. Also, I’m working in more pull-ups and chin-ups into my routine, and hitting machines less frequently. The squat racks at the gym always have a line out the door, so perhaps I’ll have to buy one myself at some point, because I don’t have the patience to wait 20 minutes (also, there’s going to be a line behind me once I do make it to the rack). Considering the amount of usage they might get it seems like an investment that might pay off? Does anyone have suggestions?

Multi-regionalism in natural selection

Screenshot - 12102015 - 03:55:03 PM

Screenshot - 12102015 - 04:26:46 PMThe human genome is littered with many genes from diverged lineages. That is, any given human has segments from lineages which are deeply diverged from the dominant demographic element in our ancestry, which diverged from an African population which flourished on ~200,000 years ago, and among non-Africans a population derived from Northeast Africa ~50,000 years ago. The Neanderthal ancestry of non-Africans, which is in the range of ~2 percent, diverged from the rest of the genome on the order of ~500,000 years ago from the main stem of our heritage. A similar time span divides us from the Denisovan ancestry in Oceanians, and to a lesser extent island Southeast Asians, and even less among East and South Asians. Due to the lack of ancient genomes such definitive inferences are more difficult to make for African populations, but there are suggestive clues that diverged lineages also contributed to the Khoe-San and Pygmy, and therefore other African, peoples.

Though the initial Neanderthal admixture results tended to focus on their implications for ancestry, and not function, a recent spate of work has suggested that archaic admixture in modern lineages may have been adaptive. But at some point one needs to go beyond genome-wide assessments, and look at specific genes. In that vein, a preprint out of Rasmus Nielsen’s group, Archaic adaptive introgression in TBX15/WARS2. This related to their paper about adaptation of Greenland Inuit to their environment. What they report here is that Greenlanders, and Eurasians more broadly as well, exhibit evidence of carrying an introgressed haplotype which derives from Denisovans or a Denisovan-related population.* The map above shows distributions of an allele which is strongly associated with the introgressed haplotype. You can see that it is absent in Sub-Saharan Africa, fixed in Greenland, present in high frequencies in the New World (near fixation in Amerindians), at moderate frequencies in East Asia, and lower frequencies elsewhere in Eurasia. The haplotype harbors two genes, TBX15 and WARS2. What do these genes do? Lots of things:

The TBX15/WARS2 region is highly pleiotropic: it has been found to be associated with a variety of traits. These include the differentiation of adipose tissue5, body fat distribution…facial morphology…stature…ear morphology…hair pigmentation…and skeletal development…Interestingly, for several of body fat distribution studies, the introgressed SNPs have significant genome-wide associations. The Denisovan alleles tend to increase waist circumference and waist-hip ratio, after correcting for BMI.

They went to great lengths to ascertain whether this was an introgressed haplotype, and where it came from in relation to the genomes we have on hand (Neanderthals, modern humans, and Denisovans). Broadly they are convincing that it is introgressed, and not deep structure from Africa. And, they make a good case that the population from which this haplotype derived is closer to Denisovans than to Neanderthals. The summary is really in the haplotype network above. To the bottom right you see a cluster of common human haplotypes. Then you see the Neanderthal haplotype, and then further along the Denisovan haplotype. Finally, you see a cluster of introgressed haplotypes. First, remember it’s not established that the donor population was Denisovan. Second, there have been derived mutations since the allele moved between populations.

The functional reason why this swept to fixation in Greenlanders seems obvious. It’s related to the nature of fat deposition, and GWAS correlate it with effects on BMI and body shape, and, it is jointly in high frequency in Amerindians and the populations of the Arctic. In all likelihood the sieve was in Beringia, where climatic conditions were extreme, and all sorts of adaptations were necessitated. And the authors state that plainly. In relation to mechanism there are suggestions that there regulatory and epigenetic dynamics at play. The expression differences seem clear, in terms of how the Denisovan variant effects the magnitude of the genetic consequence. But the epigenetic aspect is very confused to me. Part of it seems to be that the authors  themselves are trying to make sense of the results (jump to “DMR”), but I wish they would at least expand, because there is some lack of clarity as to the details (I had a friend whose research is in epigenetics read that section and they found it a bit unclear, so they didn’t want to evaluate whether it made sense, so I felt better as to my confusion).

With all that put out there, let’s get to the crux of the issue that we can agree on. Using simulations the authors did establish that this is unlikely to have increased in frequency in all these populations simply due to drift. That is, chance. The alternative then is that selection is increasing the frequency of this haplotype, and assorted functional alleles. In the case of Amerindians you see see that it is close to fixation. There is a recessive aspect to the nature of methylation patterns, which are associated with gene expression, so that may give us a clue why this variant is fixed in Greenland, and nearly so in unadmixed Amerindians. If the expression of a favored trait is recessive, then it makes sense to make the final step from ~90% (where nearly 20% of the population would have a disfavored morph) to ~99% (where only ~2% would).

But what’s going on in Old World populations? To my knowledge there is no evidence of Denisovan admixture in western Eurasian populations, but you can find these “Denisovan” alleles in them. The simplest explanation is that the haplotype is derived from another archaic population, within the same clade as Denisovans with Neanderthals as an outgroup, which was resident further west. In fact, look at the structure the introgressed haplotypes.  The Amerindians have the most diverged branch, while the western and southern Eurasian groups are represented within the haplotype closest to Denisovans. To me this is suggestive of an early admixture event closer to the point-of-departure from Africa. As modern humans moved east the serial bottleneck effect occurred with this introgressed haplotype.

A second possibility is that this allele may be from Denisovans, and that it is so favored that even if small levels of eastern Eurasian admixture don’t manifest themselves in total genome-wide admixture estimates a few copies were sufficient for this to become common outside that zone. This gets to the title of the post: one can posit a multi-regional system of selected variants sweeping across interconnected demes, which transcend the fact that migration between the demes is too low to make significant contributions to total genome content. This may explain the presence of East Asian EDAR in the Motala samples, for example.

Finally, I think one has to consider the high probability that the target of selection on this locus has varied over time and space. The introgression of this archaic allele into non-Africans was an ancient event, but it does not seem to have fixed into any populations outside of the Beringian Diaspora. Why? It may be that there are balancing effects going on, perhaps frequency dependence, or, in even over-dominance (I tend to discount the last in most cases, but the fractions in East Asia are so close to 50%). Along the East Asian littoral the frequency is in an intermediate range, while in western and southern Eurasia they’re present at lower frequencies, though lower in South Asia than in some of the European groups. This is intriguing because when it comes to alleles which are not subject to selection South Asian share more ancestry with East Eursaians, and you generally see a pattern where they occupy a position in between (e.g., this is the case when it comes to Neanderthal admixture, with East Asians having the most, and Europeans the least, with South Asians between).

There’s a lot that’s going to be researched and published between now and 2025. These authors have established that they found an introgressed variant, but it’s too widely distributed to have the neat solution that EPAS1 in Tibetans has.

* My father and brother carry one copy of the introgressed haplotype.