Selection against Neandertal deleterious alleles – “‘Approximately 2-4% of the human genome is in non-Africans comprised of DNA intro- gressed from Neanderthals. Recent studies have shown that there is a paucity of introgressed DNA around functional regions, presumably caused by selection after introgression. [U]sing previously published estimates of inbreeding in Neanderthals, and of the distribution of fitness effects from human protein coding genes, we show that the average Neanderthal would have had at least 40% lower fitness than the average human due to higher levels of inbreeding and an increased mutational load, regardless of the dominance coefficients of new mutations. Using simulations, we show that under the assumption of additive dominance effects, early Neanderthal/human hybrids would have experienced strong negative selection, though not so strong that it would prevent Neanderthal DNA from entering the human population.'” – @dienekes’…
…but see greg cochran: Degenerate Neanderthals – “Part of the problem is that the model is probably too simple. There is an argument, which makes sense to me, that suggest that small-N populations do better than you would think, because as the average population fitness gets farther from the optimum, strongly beneficial compensatory mutations become more and more possible.”
A Few Months of Evolutionary Change Reshapes a Whole Community – “The overall lesson is that evolutionary change is constant, and that evolving populations can change the very environments to which they’re adapting. Natural selection isn’t shaping species to achieve some single ideal version of themselves, but in pursuit of constantly moving targets — and that’s worth keeping in mind no matter we’re talking about Daphnia magna or Homo sapiens.”
Size (Population) Matters for Inbreeding – “Presumably, in large populations there will be many low frequency variants of weak deleterious effect and recessive expression. In contrast, in small populations the power of drift is such that even rather deleterious alleles can be fixed against the gradient of selection. At cross-purposes with this is the idea that because inbreeding populations tend to ‘expose’ alleles which express recessively to selection they can ‘purge’ the genetic load which drags on fitness…. What [the researchers] found is that in line with theoretical prediction those sampled from large populations had lots of segregating deleterious alleles, which manifested in strong inbreeding effect when individuals were purposely crossed with those genetically similar. In contrast, those from small populations did not exhibit so much inbreeding effect, indicating that a lot of the deleterious alleles were already fixed and so exposed. These individuals from small populations also exhibited lower fitness than those from large populations, reflecting in all likelihood their genetic load. Crossing individuals from different small populations resulted in immediately hybrid vigor, as the fixed variants differed across lineages.” – from razib.
Fires in the Forest: The Revolution in Human Evolution – “On top of the story of migrations of whole peoples, and the extinction and absorption of others, is the story of bands of men operating as units, related either in truth or fictively, which extract rents across a thickly populated landscape of human cattle.” – also from razib.
Regression to the Mean – “Clever people might notice that all of HBD is based on just two concepts: behavioral genetics (or again, more broadly, heritability) and the breeder’s equation. Know those two things and most of the rest follows.” – from jayman.
Deutschland über alles, dann unter allen? – dr. james thompson on an apparent reversal of the flynn effect in germany. (see also his comment here.) – see also Dysgenic Deutschland from anatoly karlin.
The Correlation Between g Loadings and Heritability in Russia – “Data from 402 twins aged 13 and 296 twins aged 16 showed correlations of r=−0.45 and r=−0.60, respectively. It is concluded that the two data points are clearly not in line with established findings. It may be that the link between g loadings and heritabilities is more complex than previously thought.” – h/t sketchy person!
Are CEOs Born Leaders? Lessons from Traits of a Million Individuals – “CEOs have higher cognitive and non-cognitive ability scores and are taller than typical members of the population. The difference in traits is larger when CEOs run bigger companies; it is smaller when they run family firms, in particular in the capacity of an heir or in a less competitive industry.” – h/t ben southwood! who tweeted: “CEOs: in the top 5% of smarts, height and well-adjusted personality at age 18”
The path and performance of a company leader: A historical examination of the education and cognitive ability of Fortune 500 CEOs – “Across the last two decades ≈ 40% of CEOs were on the top 1% of cognitive ability. Even within CEOs, education/ability was associated with company gross revenue.”
The Quantitative Genetics of Disgust Sensitivity – “Twin modeling revealed that approximately half of the variation in pathogen, sexual, and moral disgust is due to genetic effects. An independent pathways twin model also revealed that sexual and pathogen disgust sensitivity were influenced by unique sources of genetic variation, while also being significantly affected by a general genetic factor underlying all 3 disgust domains. Moral disgust sensitivity, in contrast, did not exhibit domain-specific genetic variation.” – h/t erwin schmidt!
Can intelligence explain the overrepresentation of liberals and leftists in American academia? – “Liberals and leftists are overrepresented in American academia. One explanation is that liberals and leftists have higher intelligence. This hypothesis is tested. Intelligence accounts for some but not all of the overrepresentation.”
Inter-group conflict and cooperation: field experiments before, during and after sectarian riots in Northern Ireland – “The idea that cooperative groups out-compete less cooperative groups has been proposed as a theoretical possibility for the evolution of cooperation through cultural group selection…. In this study we test the hypothesis that inter-group conflict promotes parochial altruism (i.e. in-group altruism and out-group hostility) by using longitudinal data of a real-world measure of cooperation – charity and school donations – sampled before, during and after violent sectarian riots between Catholics and Protestants in Belfast, Northern Ireland. We find that conflict is associated with reductions in all types of cooperation, with reduced donations to a neutral charity, and both in-group and out-group primary schools. After the conflict, both in-group and out-group donations increased again. In this context we find no evidence that inter-group conflict promotes parochial altruism.”
Interactions between personality and institutions in cooperative behaviour in humans – “We investigate interactions between personality and a punishment situation via two versions of a public goods game. We find that, even in a strong situation, personality matters and, moreover, it is related to strategic shifts in cooperation. Extraversion is associated with a shift from free-riding to cooperation in the presence of punishment, agreeableness is associated with initially higher contributions regardless of game, and, contrary to our predictions, neuroticism is associated with lower contributions regardless of game. Results should lead to new hypotheses that relate variation in biological functioning to individual differences in cooperative behaviour and that consider three-way interactions among personality, institutional context and sociocultural background.” – h/t andrew sabisky!
Nonreligious children are more generous – “Religious doctrines typically urge the faithful to treat others with compassion and to put the greater good before selfish interests. But when it comes to generosity, nonreligious kids seem to be more giving, according to a new study of 1170 children from around the world. Children from religious homes — particularly Muslims — also showed a greater inclination to judge someone’s misdeeds as wrong and punish the perpetrators…. Muslim children on average gave the highest rankings and sought harsher punishments than either their Christian or secular counterparts. Decety says he is unsure why this is the case.” – h/t jayman! see also staffan who tweeted: “Religious or not often coincide with Clannish and WEIRDO. A big and likely confound overlooked.” and me: “would’ve been nice if they’d broken down the race/ethnicities for the u.s., canadian, and south african samples.”
Sex and STEM Occupation Predict Autism-Spectrum Quotient (AQ) Scores in Half a Million People – “As predicted, sex and occupation differences were observed: on average, males (m = 21.55, SD = 8.82) scored higher than females (m = 18.95; SD = 8.52), and individuals working in a STEM career (m = 21.92, SD = 8.92) scored higher than individuals non-STEM careers (m = 18.92, SD = 8.48). Also as predicted, age and geographic region were not meaningfully correlated with AQ. These results support previous findings relating to sex and STEM careers in the largest set of individuals for which AQ scores have been reported and suggest the AQ is a useful self-report measure of autistic traits.”
Seven Dimensions Of Personality Pathology Are Under Sexual Selection In Modern Spain – “In a sample of 959 outpatients, we examine whether, and how, sexual selection acts on seven main dimensions of personality pathology, taking into account mating success, reproductive success, and the mediating role of status. We find that, to varying extents, all personality dimensions are under sexual selection. Far from being predominantly purifying, selective forces push traits in diverging, often pathological, directions. These pressures differ moderately between the sexes. Sexual selection largely acts in males through the acquisition of wealth, and through the duration (rather than the number) of mates. This gives a reproductive advantage to males high in Persistence-Compulsivity. Conversely, because of the decoupling between the number of mates and offspring, the promiscuous strategy of psychopaths is not so successful. Negative Emotionality, the most clinically detrimental trait, is slightly deleterious in males but is positively selected in females, which can help to preserve variation…. An evolutionary perspective on PDs can provide a better understanding of their nature and causes than we have achieved to date by considering them as illnesses.” – h/t siberian fox!
On the relationship between school suspensions, race, single-motherhood, and more and Small update to prior post on school suspension rates, comparing racial/ethnic differences with national aggregates – from mr. random c. analysis, esq.
No evidence that polygynous marriage is a harmful cultural practice in northern Tanzania – “We present counterevidence that polygyny is often positively associated with food security and child health within communities and that, although polygyny and health are negatively associated at the group level, such differences are accounted for by alternative socioecological factors. These results support models of polygyny based on female choice and suggest that, in some contexts, prohibiting polygyny could be costly for women and children by restricting marital options.” – h/t sergey gavrilets!
The missing hour of sleep – “In reality, there is no single human nature. Genetic evolution didn’t slow down when humans began to split up and settle the different continents. It accelerated. And not just because our ancestors were adapting to different natural environments. Most of the acceleration took place long after the globe had been settled from the equator to the arctic. It happened when humans began to adapt to an increasingly diverse range of cultural environments. And those adaptations were mostly behavioral and psychological. One of them is the way we sleep. The African sleep pattern is normal in its native environment. It is simply an adaptation to a particular set of circumstances, just as the northern European sleep pattern is an adaptation to another set of circumstances.” – also from peter frost.
Heritability of Racial and Ethnic Pride, Preference, and Prejudice – “[I]t does seem that individual differences in expressed ethnic and racial preference have a non-trivial genetic basis, as we might have anticipated given that most social preferences do.” – also from chuck.
Genetic and socioeconomic study of mate choice in Latinos reveals novel assortment patterns – “In Mexican and Puerto Rican couples, we find that partners share more similar genomic ancestries, which is characterized as the fractions of genome that come from European, Native American, and African ancestries, than random pairs of individuals from the same community. Our analysis shows that this similarity cannot be explained by the individuals’ socioeconomic factors alone.” – h/t ben southwood and jayman!
Cognitive ability and tattoos and piercings – from emil kirkegaard. (full disclosure: i don’t have any tattoos, nor do i have any “extreme” piercings. (~_^) )
Corruption In Eastern Europe: Tail Or Dog? – from malcolm pollack.
Huxley: Brave New World Revisited – from steve hsu. also Houellebecq on Tocqueville, Democracy, and Nietzsche.
Crashing the Gates: A Crash Course – from m.g. @thosewhocansee on the european migrant crisis.
Changes in Inequality and Generalized Trust in Europe – “This paper analyses the determinants of trust in a pool of 34 European countries over the period 2002–2012. We find that income inequality is negatively related with generalized trust when we analyze the pooled data of individuals with multilevel models, confirming a well-established result in the analysis of cross-country differences in trust…. In contrast, in the fixed effects models, we find negative and significant effects of ethnic and linguistic fractionalization, discrimination (general or based on migrant status) and crime rates on trust.” – behind a paywall.
Why Did Asian America Abandon the GOP? – short answer: the shifting composition of asian americans. – from t.greer.
Het ‘verboden onderwerp’: Inteelt is weldegelijk moslimprobleem – from joost niemöller. in dutch [obv]. h/t sam schulman! who tweeted: “Warning to geneticists: stay out of the #Netherlands. They’re arresting those who mention cousin marriage.”
bonus bonus: The greatest vanishing act in prehistoric America – “Seven centuries ago, tens of thousands of people fled their homes in the American Southwest. Archaeologists are trying to work out why.”
bonus bonus bonus bonus: Thank heavens, someone figured out which bacteria live on a donkey’s penis – (O.O)
bonus bonus bonus bonus bonus: Ancient mummified hand hidden in wall of Yorkshire cottage ‘has power to entrance humans’ – a hand of glory?!
and the tweet of the week! (i almost forgot)…
(note: comments do not require an email. smile!)