The studies to test that directly haven’t been done yet. However, for muscle strength and sprinting performance in non-athletes ACTN3 explains around 2-3% of the variance, so it’s probably of that order of magnitude (actually probably slightly less) for endurance running.

Aug: very interesting work. I’ve sent your post to a colleague who’s doing some phylogenetic analysis of the actinins, including in zebrafish. We’ll be in touch. 🙂

So am I right to read this as a strong argument against those who say Ethiopians are the winners of long-distance running competitions because of those claimed African long-distance running genes? 
 
It’s a strong argument against ACTN3 playing a major role in the dominance of east Africans in endurance events. We’ve tested this directly: comparing east African controls and athletes there’s no significant difference in ACTN3 allele frequencies (although we had reduced power due to low allele frequency). 
 
That’s very different from saying that the east African dominance doesn’t have any genetic component – it’s pretty clear that it does.

The “endurance” version of the ACTN3 gene has a low frequency (~10%) throughout most of Africa, and a higher frequency (~50%) pretty much everywhere else (Europe, Asia, the Middle East, Oceania), with some variation.

Thanks razib – I’ll try again. 
 
Disclaimer: I’m an author on this paper. 
 
bioIgnoramus: The quote from the news article about arising in the last ice age is a bit dubious. In reality the selection events could have begun anywhere between 10 and 50,000 years ago, but they’re certainly more recent in Europe than East Asia. 
 
We don’t think selection was on endurance capacity per se (although I guess that’s possible). More likely the increased muscle metabolic efficiency provided resistance to famine, or maybe there’s some impact on cold tolerance. Eurasia obviously provided plenty of novel environmental challenges – we’re still trying to figure out which was the major player in this case. 
 
Kris: yep, there’s definitely compensation from actinin-2. In our last paper (in Nature Genetics) we showed that actinin-2 is up-regulated in the KO mouse and shifts its expression to take over where actinin-3 goes missing. In humans actinin-2 is already expressed in all muscle fibres, so we think it plays a compensatory role there too. 
 
Knocking out actinin-2 would almost certainly result in embryonic lethality since it’s the sole isoform in the heart. We have collaborators working on a muscle-specific KO as we speak. 
 
Can you spell out exactly which “data don’t look so great” to you? Bear in mind those are 95% CIs on the histograms, not SEMs. Some of the phenotypes are certainly subtle – but that’s really what we expected, given the mild phenotype in human “knockouts” (20% of the population!).

I have a longish comment on this thread that I guess has been caught in a moderation queue – any suggestions on how to get it out?

Hey Razib,
This is my baby (as in, I’m first author on the paper).
We thought about selection for cold tolerance, but our latest data on global distribution of the null allele don’t really fit with that. Most likely it’s something to do with famine resistance, although we’re not ruling out the idea that it’s selection for some sort of muscle performance phenotype (it’s surprising how many muscle genes are popping up in recent genome-wide scans for selection).
We haven’t got genotype distributions for the Kalenjin yet, but we have a paper due out soon that shows a disappointingly low frequency of the null allele in Kenyans in general, and no association with athletic performance in that population. Looks like other genes (and environmental factors) are responsible for the spectacular endurance performance of East Africans.

eIF4E is definitely a strange choice of control; they used H3 histone for their qPCR analysis, which seems much more appropriate (and tubulin or beta-actin are the conventional choices, as you point out). I’d actually basically ignore their Western blot data – quantitation of Western data can be so subjective anyway, and their qPCR data is reasonably compelling by itself.

So the typical GNXP reader is a white, male, atheist libertarian who sees himself as moderately wealthy, reads other blogs, and has been visiting here for between one and two years. I can’t say I’m surprised, although the sheer strength of the skew in some of those variables is interesting. 
 
I agree that a question on IQ would be interesting, although of course the results would have to be taken with a large pinch of salt.

I think it’s potentially a really useful way of bringing the GNXP community together (and as razib noted, it was cool to be able to lightly quiz John Hawks about introgression in real-time). 
 
But the quality of the conversation will all depend on who is online at the time you log on – i.e. whether it’s John Hawks, dfsf, or just a bunch of anonymous “guest9” lurkers. If it lasts, it may reach a nice equilibrium where people figure out which time of day is best to log on, and a large group of people can engage in a useful and free-ranging conversation. Or it may just fade away in a few days into terminal inactivity. We’ll see.

Oxygen, 
 
Heh, thanks – for a country that was never previously interested in football, that penalty seems to have left a bizarrely large scar on the national psyche.

As an Australian, I’ve been inculcated with a strong anti-elitist streak and an automatic preference for the underdog and the iconoclast. I instinctively dislike anyone who “talks themselves up,” avoiding self-promotion where possible in preference for self-deprecation (this results in a fairly strongly ingrained bias against Americans, who often seem to have a boisterous self-confidence that is like fingernails down a blackboard).

I saw Jahn present this work last week – I don’t think I’ve ever seen such a comprehensive analysis of any biological system. One thing that stuck in my mind is him casually flashing up a slide showing ~80 quantitative Western blots, all of which had been optimised and analysed by his post-doc Takamori (the first author on this paper). When he reached the 3D model of the vesicle and started rotating it on-screen there was an audible gasp from the audience. This is truly inspiring science.

One thing that seems to be being glossed over: the cuckoldry-avoidance theory can only hold if people are actually aware of the significance of eye colour in a genetic (i.e. paternity-indicating) sense. But is there any evidence that pre-modern humans actually knew that two blue-eyed parents can only have blue-eyed children? It seems to me entirely likely that for much of human evolutionary history, people were largely (or totally) ignorant of eye colour inheritance – and if this is true, the selective value of blue-eyed men seeking blue-eyed women for paternity assurance purposes would have been zero.

Asian (75%) > African (~50%) > European (25%) 
 
Odd distribution… maybe selection against this allele in Europeans?

The species split idea is interesting (albeit unoriginal, as Mustafa points out). Combine assortative mating for SES/IQ (I assume this exists, perhaps razib could comment) with genetic enhancement available only to the rich, and you may just have all the ingredients for speciation, given sufficient time.
Of course, this only applies if the rich/poor divide remains stable over a long enough period of time, which is an open question.

From what I’ve seen it’s exactly like the selectionist vs neutralist (or the even more absurd “nature vs nurture” debate) – the few extremists on either side get the press, and the mainstream science media love to frame it as a dichotomy, but most reasonable scientists sit quite happily somewhere in the middle. 
 
On the other hand, I think the regulatory people need to kick up a fuss every now and then because there are so many more tools for examining coding region evolution, so sometimes molecular evolutionists simply forget about regulatory regions – the classic “it’s too hard to examine and therefore irrelevant” phenomenon seen in all fields of science.

The odds that leftists (or, shall we say, the leftist establishment) will believe something is a function of the strength of the evidence for it and its “coefficient of friction” with their doctrine. 
 
That’s pretty much a universal human trait, not something specific to “leftists”. Most people on the conservative side of politics also struggle with empirical realities that clash with their traditions and dogma. We’re just not built to be rational calculating machines.

I’m not a huge fan of the outlier approach either – but in the absence of the information about the demographic history of humans required to generate appropriate theoretical distributions (via coalescent sims) it seems like a reasonable halfway house. In a few years we’ll have the requisite population genetic data to reconstruct human demographic history in some detail, and then we can start using theoretical distributions with confidence. Until then, outliers it is. 
 
The linkage-based approaches seem solid, although I’ve run into some trouble using them in practice – local variation in recombination rate creates a great deal of noise (at least, more than I expected to see). The first-pass genome scans currently being published are cluttered with false positives, and they’re also missing at least a few important regions – I know this because I’ve found at least one clear signal using my own algorithms that’s been missed by all the published genome-wide scans. 
 
But imagine the situation in ten to twenty years time – we should have genome-wide complete resequencing data for enough humans from enough ethnic groups to pull out virtually every region that’s been subject to recent local or global selection. By then, the algorithms will be good enough to dissect out selection with much higher accuracy, and genome annotation will be good enough to assign functions to nearly all of those loci. We’ll basically have a rough history of nearly every selective pressure that humans have faced – with estimates of age and selective strength – for the last few 100 KY. Exciting times…

Tajima’s D isn’t useless on the HapMap data-set – you just use an empirical distribution (i.e. the genome-wide data-set) to estimate significance rather than the standard theoretical distribution (which has always been of uncertain utility anyway, since the underlying demographic assumptions are clearly wrong for humans). Assuming that all loci are affected equally by demography and only a subset of loci have been subject to recent positive selection, this should be a valid approach for detecting recent sweeps. 
 
A bigger problem, IMO, is that Tajima’s and other tests are only useful when the sweep has proceeded to close to fixation. It’s likely that many variants under recent positive selection aren’t anywhere near fixation – Tajima’s won’t see these at all. However, these should be detected by the linkage-based methods developed recently (see here and here).

I did.

razib, 
 
The Telic Thoughts crew are generally honest as IDists go; but then they espouse a form of ID that is pretty close to mainstream evolutionary theory anyway, just with the possibility of an ancient “front-loading” event (i.e. the deliberate design of the first living cells). Since they accept most of the unambiguously supported tenets of modern evolutionary theory (i.e. common descent, macroevolution, random mutation and natural selection) there’s not much need for dishonesty on their part. There’s definitely some Dawkins-bashing and claims of scientific censorship, but I don’t entirely disagree with their points on those topics either.

Thanks for that – I appreciate your frankness. The reason I asked (apart from simple impolite curiosity) is because I have suspected a similar thing about myself for more than a little while, although I’ve never phrased the thought in those exact terms. Most people seem to intuitively get the way other people work, but not me; it’s always been a difficult, higher-order cognitive process for me. It’s good to meet a fellow sociopath, if that’s what I am. 🙂
Anyway, enough group therapy. I enjoyed the article you linked to (or at least the one-third of it that I’ve had time to read so far), although I must admit that I don’t have the background to understand many of its nuances. The unfortunate thing about these deeply counter-intuitive concepts is that they will only ever really be relevant to the elite – those with the inclination and time to read them, and the education and intelligence to comprehend them – and cannot readily be condensed down to a version palatable to the masses. As such the majority of humanity will forever remain happily ignorant of the deeper cognitive bases for their own beliefs.
On the other hand, I can think of a whole host of reasons why this is probably for the best…

(I am pretty sure I have an attenuated Theory of Mind for example)

Intriguing… razib, would it be too much of an intrusion to ask you to expand on this?