linkfest – 11/10/15

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.

Polygyny makes men bigger, tougher … and meaner and The contradictions of polygyny – from peter frost.

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.

The Measured Proficiency of Somali Americans – from chuck @humanvarieties. see also: Chisala and Powerpoint Publishing from dr. james thompson.

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. (~_^) )

G. E. Moore Contra Edvard Westermarck and The Moral Philosophy of G. E. Moore, or Why You Don’t Need to Bother with Aristotle, Hegel, and Kant – from helian.

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: Did Africa’s Apes Come From Europe?“Fossil evidence hints that the common ancestor of gorillas, chimpanzees and humans evolved in Europe.” – h/t billare!

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: Thanet, Tanit and the Phoenicians: Place-Names, Archaeology and Pre-Roman Trading Settlements in Eastern Kent?

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)…

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why human biodiversity (hbd) is true

we know that human biodiversity (hbd) is true because, for one thing, we have many, many examples of it (see here)!

additionally, both the workings of the natural world and specifically the theory of evolution predict that hbd must be the case.

nature likes to throw up variety (see here for example) — the variation between individual organisms is, after all, what natural selection acts upon — and there’s no reason for humans to be any exception. add to that the fact that humans reproduce sexually — with all the genetic shuffling and remixing that happens there — and it’s inevitable that individual humans will be biologically diverse.

various groups or populations of humans — ranging from small-sized families to races and even beyond (for example, think: east asians+native americans together compared to caucasians or subsaharan africans) — will also inevitably be biologically diverse from one another, to greater or lesser degrees, due to forces of evolution such as natural selection, gene flow, and/or genetic drift.

keep in mind that humans — including various discrete-ish human populations (biological borders are fuzzy, naturally) — have experienced recent evolution (i.e. within the last 40,000 years or so), that human evolution has probably sped up since the advent of agriculture, and that we are undoubtedly still evolving today.

ignoring or denying the existence of human biodiversity won’t make it go away. hbd — and its implications — will remain a reality in spite of all your hopes and dreams, however well-intentioned they may be.
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this is one of a set of posts on What is Human Biodiversity? please, before you fire off a rant leave a comment here, check out the other posts, because your question or objection may have been dealt with in one of them. here they all are!:

what is human biodiversity (hbd)?
what human biodiversity (hbd) is not
examples of human biodiversity (hbd)
hbd and racism
hbd and politics

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linkfest – 10/14/12

today, some classics (and soon-to-be classics?):

Latitude, elevation and the tempo of molecular evolution in mammals“[B]ecause climatic variables change with latitude and elevation in a similar manner, our results suggest that climate has influenced the tempo of genetic change in mammals…. These findings provide new insights into microevolution that are likely to have important implications for understanding global patterns of biodiversity and diversification.”

An Asian perspective on early human dispersal from Africa“Asia might not have been the passive recipient of whatever migrated out of Africa but might have been a major donor to speciation events, as well as dispersals back into Africa. Such two-way traffic is well documented for other mammals in the Pliocene and Early Pleistocene, such as Equus and bovids, with more taxa migrating into than out of Africa. There is no reason why hominin migrations were always from Africa into Asia, and movements in the opposite direction might also have occurred, as has been suggested for the Olduvai OH9 (refs 13, 58) and Daka specimens. We should even allow for the possibility that H. ergaster originated in Asia and perhaps explain its lack of an obvious east African ancestry as the result of immigration rather than a short (and undocumented) process of anagenetic (in situ) evolution (Dennell and Roebroeks 2005:1100-1101).” – see also: Did Early Humans First Arise in Asia, Not Africa?

Recent acceleration of human adaptive evolution“It is sometimes claimed that the pace of human evolution should have slowed as cultural adaptation supplanted genetic adaptation…. Cultural changes have reduced mortality rates, but variance in reproduction has continued to fuel genetic change. In our view, the rapid cultural evolution during the Late Pleistocene created vastly more opportunities for further genetic change, not fewer, as new avenues emerged for communication, social interactions, and creativity.” – hawks, wang, cochran, harpending & moyzis.

Innate Social Aptitudes of Man: An Approach from Evolutionary Genetics [opens pdf] – w.d. hamilton.

How obedience of marriage rules may counteract genetic drift“Continuous unilateral or bilateral cross-cousin mating, reflecting the most common form of prescribed marriage, increases homozygosity but at the same time slows down considerably the loss of gene diversity due to genetic drift.”

It’s All Relative: Race as partly inbred extended family – from steve sailer.

Human genetic diversity: Lewontin’s fallacy [opens pdf] – “In popular articles that play down the genetical differences among human populations, it is often stated that about 85% of the total genetical variation is due to individual differences within populations and only 15% to differences between populations or ethnic groups. … This conclusion, due to R.C. Lewontin in 1972, is unwarranted because the argument ignores the fact that most of the information that distinguishes populations is hidden in the correlation structure of the data and not simply in the variation of the individual factors.”

Discerning the Ancestry of European Americans in Genetic Association Studies“Here we mine much larger datasets (more markers and more samples) to identify a panel of 300 highly ancestry-informative markers which accurately distinguish not just northwest and southeast European, but also Ashkenazi Jewish ancestry.”

Genes predict village of origin in rural Europe“After excluding close kin and inbreeding, village of origin could still be predicted correctly on the basis of genetic data for 89–100% of individuals.”

E Pluribus Unum: Diversity and Community in the Twenty-first Century [opens pdf] – “New evidence from the US suggests that in ethnically diverse neighbourhoods residents of all races tend to ‘hunker down’. Trust (even of one’s own race) is lower, altruism and community cooperation rarer, friends fewer.” – robert putnam.

The Misguided Advocates of Open Borders“Rising diversity within human societies tends to drive people apart, causing them to take sanctuary in individual pursuits and ethnic communities. The practical consequences are reduced public altruism or social capital, evident in falling volunteerism, government welfare for the aged and sick, public health care and a general loss of trust. Ethnic diversity is second only to lack of democracy in predicting civil war. Globally it correlates negatively with governmental efficiency and prosperity.” – frank salter.

Why g Matters: The Complexity of Everyday Life [opens pdf] – linda gottfredson.

State IQ estimates (2009) – from the awesome epigone.

Inbreeding depression and IQ in a study of 72 countries [opens pdf]. see also Consanguinity and national IQ scores.

American Murder Mystery“Why is crime rising in so many American cities? The answer implicates one of the most celebrated antipoverty programs of recent decades.” – h/t anonymous.

bonus: Ethnic differences: Variation in human testis Size – jared diamond.

bonus bonus: Late Middle Eocene primate from Myanmar and the initial anthropoid colonization of Africa

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evolution likes it hot

i posted about this before, but the topic came up in conversation recently, so i thought i’d post about it again:

“Evolution faster when it’s warmer”
24 June 2009

“Climate could have a direct effect on the speed of ‘molecular evolution’ in mammals, according to a study.

“Researchers have found that, among pairs of mammals of the same species, the DNA of those living in warmer climates changes at a faster rate.

“These mutations – where one letter of the DNA code is substituted for another – are a first step in evolution.

“The study, reported in Proceedings of the Royal Society B, could help explain why the tropics are so species-rich….

“The idea that microevolution happens faster in warmer environments is not new. But this is the first time the effect has been shown in mammals, which regulate their own body temperature.

“‘The result was unexpected,’ said Len Gillman from Auckland University of Technology, who led the study.

“‘We have previously found a similar result for plant species and other groups have seen it in marine animals. But since these are “ectotherms” – their body temperature is controlled directly by the environment – everyone assumed that the effect was caused by climate altering their metabolic rate….’

“‘We suspected the same effect might be happening in mammals, because seasonal changes affect the animals’ activity,’ Dr Gillman told BBC News.

“He and his team compared the DNA of 130 pairs of mammals, looking at genetically similar ‘sister species’ – where each of the pair lived at a different latitude or elevation.

“They tracked changes in one gene that codes for a protein known as cytochrome b, comparing the same gene in each of the pair of mammals to a “reference” gene in a common ancestor.

“By looking for mutations in the DNA code for this gene – each point where one letter in the code was substituted for another – the researchers were able to see which of the two mammals had ‘microevolved’ faster.

“Animals living in environments where the climate was warmer, had about 1.5 times more of these substitutions than the animals living in cooler environments.

“Dr Gillman explained that, at higher latitudes where environments are colder and less productive, animals often conserve their energy – hibernating or resting to reduce their metabolic activity.

“‘In warmer climates annual metabolic activity is likely to be greater, so this will lead to more total cell divisions per year in the germline.’

“These results support the idea that high tropical biodiversity is caused by faster rates of evolution in warmer climates.”
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here’s the original research article: Latitude, elevation and the tempo of molecular evolution in mammals

one of the first things that popped into my mind — right after cool! — when hearing about this a few years ago was: so what could this mean for the out-of-africa (ooa) theory? one of the foundational pillars of ooa is that, because genetic variation is greatest in africans, they must be some of the oldest populations on earth ’cause they’ve acquired so many, many mutations — therefore, everyone else prolly came ooa:

“A 10-year study published in 2009 analyzed the patterns of variation at 1,327 DNA markers of 121 African populations, 4 African American populations, and 60 non-African populations. The research showed that there is more human genetic diversity in Africa than anywhere else on Earth….

“Human genetic diversity decreases in native populations with migratory distance from Africa and this is thought to be the result of bottlenecks during human migration, which are events that temporarily reduce population size. It has been shown that variations in skull measurements decrease with distance from Africa at the same rate as the decrease in genetic diversity. These data support the Out of Africa theory over the multiregional origin of modern humans hypothesis.”

but if genetic variation might be increased just by living in a hot climate … well … then what?

more recently, davidski over at eurogenes posted about this paper the other day: An Abundance of Rare Functional Variants in 202 Drug Target Genes Sequenced in 14,002 People. turns out african americans have a lot more rare genetic variants than europeans — and northern europeans have the least of all:

could the differences be related to the fact that these people’s ancestors came from different latitudes/climates and, so, their mutation rates were different? dunno. maybe.

previously: here’s my question

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here’s my question

ok. so, we’re all out of africa, right?

and one of the reasons for thinking this is ’cause there’s greater genetic diversity in african populations than non-africans suggesting, from what i understand, a population bottleneck in those groups who left africa and greater genetic drift back in the african population. (amiright?)

but, mutation rates are higher in hot climates than cold (edit: see better link re. mammals here), so couldn’t the greater genetic diversity in africans simply be a product of that effect?

see what i’m sayin’/askin’?

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