Archives for posts with tag: polygyny

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)…

(note: comments do not require an email. smile!)

Deep-ocean microbe is closest living relative of complex cells“A new study indicates that plants, fungi, and animals are descendants of archaea, the group of single-celled organisms that includes Sulfolobus, a resident of hot springs.” – h/t bill barendse! – see also: New Loki Microbe Is Closest Relative To All Complex Life.

A Surprise for Evolution in Giant Tree of Life“Researchers build the world’s largest evolutionary tree and conclude that species arise because of chance mutations — not natural selection…. This controversial proposal stems from efforts by Hedges and collaborators to build the world’s most comprehensive tree of life — a chart plotting the connections among 50,000 species of Earth’s vast menagerie. Their analysis suggests that speciation is essentially random. No matter what the life form — plant or animal, insect or mammal — it takes about 2 million years for a new species to form. Random genetic events, not natural selection, play the main role in speciation.” – see also Was Charles Darwin Wrong About Speciation? from razib.

Genetic changes to basic developmental processes evolve more frequently than thought“Newly evolved genes can rapidly assume control over fundamental functions during early embryonic development. The findings suggest that evolutionary changes to the genetics of fundamental biological processes occur more frequently than previously thought.” – h/t david bachinsky!

The First GMO Is 8,000 Years Old“Scientists find that bacteria modified DNA in sweet potatoes millennia ago.”

Behavioral idiosyncrasy reveals genetic control of phenotypic variability [pdf] – “If we could rear genetically identical individuals from a variety of genetic backgrounds and rear them in the same environment, how much phenotypic variation between individuals of the same genotype would we see? Would different genetic backgrounds differ in their degree of variability? What would account for these differences? We used Drosophila inbred lines to address these questions focusing on variability in locomotor handedness. We show that different genotypes vary dramatically in their propensity for variability, that phenotypic variability itself, as a trait, can be heritable, and that loci affecting variability can be mapped. The genetic control of variability has received little attention in quantitative genetics despite the important role variability plays in explaining phenotypic variation between individuals.”

two tweets from the Biology of Genomes meeting re. a presentation on mutation rates:

Team Characterizing DNA from Ancient Human with Recent Neanderthal Ancestry [registration req.] – see also Ancient DNA from an Upper Paleolithic European with recent Neanderthal ancestry“the male sample, Oase 1, is 37-42K years old and comes from the Pestera cu Oase site in southwestern Romania. it’s estimated to harbor 5-11% of genome-wide Neanderthal ancestry, with as much as 50% on chromosome 12. the admixture is in relatively long stretches, which suggests that the mixture took place four to six generations before Oase 1 was alive. – @the eurogenes blog.

The archaeology, chronology and stratigraphy of Madjedbebe (Malakunanja II): A site in northern Australia with early occupation“The stone artefacts and stratigraphic details support previous claims for human occupation 50–60 ka and show that human occupation during this time differed from later periods.” – h/t chris stringer!

Stone bracelet is oldest ever found in the world“Dating back 40,000 years to the Denisovan species of early humans, new pictures show beauty and craftsmanship of prehistoric jewellery.” – denisovan jewelry!!

The Old Race – from greg cochran.

Ancient DNA Tells a New Human Story“The study of ancient DNA has challenged this view. We now know that mass migrations occurred repeatedly, overwhelming natives while absorbing some of their genes…. Joseph Pickrell of Columbia University and David Reich of Harvard University argue that ‘major upheavals’ of human population have been ‘overwriting’ the genetic history of the past 50,000 years. The result, they say, is that ‘present-day inhabitants of many places in the world are rarely related in a simple manner to the more ancient peoples of the same region.'” – from matt ridley.

2,500-year old Etruscans“All that can be said based on this is that they seem broadly southern European and not particularly Tuscan.” – from dienekes. – h/t anthropology tip!

The time and place of European gene flow into Ashkenazi Jews – @the eurogenes blog.

Symbolic bones and interethnic violence in a frontier zone, northwest Mexico, ca. 500–900 C.E.“Persistent interethnic violence has affected some global regions for centuries…. In the prehispanic Northern Frontier of Mesoamerica, approximately 500–900 C.E., people of different ethnic backgrounds struggled for standing in a shifting sociopolitical landscape. Evidence is consistent with long-term social violence….” – h/t gaetan burgio!

London Conference on Intelligence 2015 Keynote – from dr. james thompson.

NIH bans funding for genetic engineering of human embryos – (>.<)

Three hundred years of low non-paternity in a human population“Here we use this approach to investigate 1273 conceptions over a period of 330 years in 23 families of the Afrikaner population in South Africa. We use haplotype frequency and diversity and coalescent simulations to show that the male population did not undergo a severe bottleneck and that paternity exclusion rates are high for this population. The rate of cuckoldry in this Western population was 0.9% (95% confidence interval 0.4–1.5%), and we argue that given the current data on historical populations we have to conclude that, at least for Western human populations, cuckoldry rate is probably in the range of 1%.” – h/t debbie kennett!

Genius and autism may share genetic link, study finds“Child prodigies and their autistic family members may share a genetic link, according to findings published online for the April issue of Human Heredity.”

Immediate susceptibility to visual illusions after sight onset – h/t laura kelley!

The glass is half full *and* half empty: A population-representative twin study testing if optimism and pessimism are distinct systems“Here, we addressed these questions in a genetically informative sample of 852 pairs of twins. Distinct genetic influences on optimism and pessimism were found. Significant family-level environment effects also emerged, accounting for much of the negative relationship between optimism and pessimism, as well as a link to neuroticism. A general positive genetics factor exerted significant links among both personality and life-orientation traits. Both optimism bias and pessimism also showed genetic variance distinct from all effects of personality and from each other.” – h/t stuart ritchie!

Stanford researchers observe the moment when a mind is changed

Nature or nurture? Are sporting champions born to win? – h/t razib!

Menstrual Cycle Phase Does Not Predict Political Conservatism

Heritability of decisions and outcomes of public goods games

The kind of student you were in elementary school predicts mortality – h/t timothy bates!

The Mask of Sanity Revisited: Psychopathic Traits and Affective Mimicry – h/t claire lehmann! who tweeted: “People with psychopathy can produce highly convincing but fake expressions of feelings.”

Polygyny without wealth: popularity in gift games predicts polygyny in BaYaka Pygmies – h/t steve stewart williams!

The kin selection argument continues, with those denying its importance holding firm. They’re wrong. – from jerry coyne.

Behaviorism and the revival of antiracism – from peter frost.

Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles – hmmmm. really? – see also: What your smile says about where you’re from“If you come from a country of immigrants, you’re more likely to crack a friendly smile on the street. That’s the conclusion of a new study, which may explain why Americans beam more than their Chinese and Russian counterparts.”

Is reading to your kids “unfairly disadvantaging” others? – hahahahahaha! – h/t brian boutwell! who tweeted: “The nonsense that you can believe when you’re convinced that genes don’t matter.” – see also Is having a loving family an unfair advantage?

How uncommon is tickertaping? Prevalence and characteristics of seeing the words you hear – h/t kevin mitchell!

Peter Visscher: Genomics, Big Data, Medicine, and Complex Traits – @steve hsu’s.

Memes are Genes – from evolution theorist. (where do memes come from?) – h/t jayman!

How can our future Mars colonies be free of sexism and racism? – (>.<) #virtuesignalling – h/t ed west!

Paternity Case for a New Jersey Mother of Twins Bears Unexpected Results: Two Fathers – ruh roh!

After Nearly Claiming His Life, Ebola Lurked in a Doctor’s Eye“Before he contracted Ebola, Dr. Ian Crozier had two blue eyes. After he was told he was cured of the disease, his left eye turned green [temporarily].” – whoa.

How music evolves“Statistical analysis of music reveals the truth about its periods of revolution.” – h/t argumatronic!

The Medieval Roots of Our DIY Gun Culture“Forget 3-D printers. The first garage gunsmiths date back to the late Middle Ages.”

When Baltimore Shook With Anger, Here’s What China Saw“Online reaction revealed much about Chinese tension with an influx of African immigrants.” – h/t holtz!

No, there’s no “hate speech” exception to the First Amendment – duh. – from eugene volokh.

bonus: The migration of the eagle hunters – awesome!

(note: comments do not require an email. kazakh eagle hunter!)

i thought i’d start running through pinker’s “war deaths chart” to see if i can work out any/some of these populations’ mating patterns. already posted about the semai (low violence rates, outbreeders) and the yąnomamö (greater violence rates than the semai, inbreeders).

now i’m just going to begin at the top of the list and work my way down — so today it’s the cato kato indians of california (or the cahto depending on your spelling preferences):

pinker - war deaths per 100,000 people per year - the kato

as you can see, the kato are at the top of pinker’s list. (in the 1840s, the kato were fighting the yuki, so remind me to post about them, too.)

from The North American Indian. Volume 14 [pg. 11]:

Marriage was arranged between the two persons concerned without consulting anybody else. Having secured a girl’s consent her lover went clandestinely that night to sleep with her, and at dawn he stole away. The secret was preserved as long as possible, perhaps for several days, and the news of the match transpired without formal announcement, even the girl’s parents learning of their daughter’s marriage in this indirect fashion. His marriage no longer a secret, the young man might then erect a house of his own. The bond was no more easily tied than loosed, for either could leave the other for any reason whatever, the man retaining the male children and the woman the female. Children were not regarded as belonging any more to the paternal than to the maternal side. When adultery was discovered, the only result was a little bickering and perhaps an invitation to the offender to take up permanent relations with the new love.”

sounds like cousin marriage was not insisted upon in kato society. otoh, sounds like there were no proscriptions against it, either. so matings in kato society could’ve been close — at least some of the time.

from Native Americans: An Encyclopedia of History, Culture, and Peoples [pgs. 156-57]:

Marriage was generally a matter between the couple involved, although girls were generally prepubescent when married. The Cahto practiced polygyny as well as the taboo that prevented a man from addressing his mother-in-law directly. Divorce was easily obtained for nearly any reason.”

again, no apparent insistence upon, or prohibitions against, cousin/other close marriage. however, from here [pg. 247] we learn that the pre-contact kato population was ca. 1,100 individuals. that’s not very many! with such a small population, it would be very difficult, indeed, to avoid inbreeding. (don’t forget, too, because native americans went through a bottleneck coming to the americas, they’re all relatively related to one another — genetically speaking. so any inbreeding would be even more inbred than in other populations — if that’s the right way to put it [i know it’s not!].)

interestingly, from Handbook of North American Indians, Volume 8: California [pg. 244]:

“The Cahto lacked a true tribal organization. During precontact time there are estimated to have been 50 villages, with the permanent settlement situated in the three valleys where the town of Cahto once stood, and the towns of Branscomb and Laytonville now stand.”

another question is whether or not the kato married non-kato people. they were, apparently, on quite friendly terms with the pomo indians and many of them spoke pomo. did they marry out? dunno.

so, the kato? i’m gonna call it: probable inbreeding.

kato lady (she looks nice!):


previously: the semai and the fierce people

(note: comments do not require an email. cato.)


Get every new post delivered to your Inbox.

Join 394 other followers