linkfest – 10/19/15

First humans to leave Africa went to China, not Europe“The first humans to leave Africa decamped to far east Asia, not Europe. A trove of ancient teeth found in a cave in China adds evidence to the idea that humans reached the region thousands of years before they made it to Europe. The find suggests that modern humans reached China between 80,000 and 120,000 years ago. That challenges the widespread assumption that humans didn’t leave Africa until 60,000 years ago. It’s further evidence that Homo sapiens may have left Africa several times, says María Martinón-Torres of University College London. ‘It means we have to re-think different models of our dispersal.'” – and john hawks tweeted: “An 80kya modern human population in SE Asia w/Denisovan ancestry might help explain pattern of admixture in Philippines Mamanwa.”

Way Down South“I hear (tweets by Razib Khan, concerning Sankararaman’s talk at ASHG) that the Denisovans had substantially more genetic diversity than Neanderthals (determined mainly by the variety seen in admixed segments)….” – from greg cochran.

Lactase persistence and ancient DNA“‘…it seems plausible to me that the [European LP] allele first appeared in Central Europe, was spread around Europe by the LBK, before being introduced to the steppe later by migration from Europe.'”

Stonehenge builders had barbecue feasts at nearby party centre – and milk and cheeeeeese!

Basques are not simply a fusion of Iberian hunter-gatherers and early farmers“[T]he story told by the PCA is that Basques are the progeny of Bronze Age Iberians, who, unlike their Copper Age predecessors, experienced a pulse of steppe-related admixture from the east…. The key question now is who brought the steppe-related ancestry to Basque country. Were they Indo-Europeans or speakers of Proto-Basque?”

Sex‐specific demography and generalization of the Trivers–Willard theory – h/t owen jones! who tweeted: “Can mothers adaptively adjust offspring sex ratio? It’s complicated….”

The Great Migration and African-American genomic diversity“We find higher African ancestry in southern United States compared to the North and West. We show that relatedness patterns track north- and west-bound routes followed during the Great Migration, suggesting that admixture occurred predominantly in the South prior to the Civil War and that ancestry-biased migration is responsible for regional differences in ancestry. Rare genetic traits among African-Americans can therefore be shared over long geographic distances along the Great Migration routes, yet their distribution over short distances remains highly structured.”

Connectivity matrix predicts fluid intelligence“The enchanted loom is slowly giving up its secrets, of which it holds many. The patterns of brain activity that so many researchers have tracked with wonder are beginning to reveal a larger pattern: the possibility that each of us has a habitual pattern of brain activity which identifies us, and distinguishes us from others. So, dear reader, we are separated by the idiosyncratic rhythms of our brains, dancing to a different beat, visiting a different pattern of cortical locations, and no doubt coming to different conclusions…. The unexpected finding which I find startling is that individuals can be identified by their habitual brain patterns (not just on specific tasks) and those patterns of activity predict fluid intelligence on Raven’s Matrices at about r=0.5.” – from dr. james thompson.

Meta-analysis of associations between human brain volume and intelligence differences: How strong are they and what do they mean?“Positive associations between human intelligence and brain size have been suspected for more than 150 years…. Our results showed significant positive associations of brain volume and IQ (r = .24, R2 = .06) that generalize over age (children vs. adults), IQ domain (full-scale, performance, and verbal IQ), and sex…. We show that the strength of the positive association of brain volume and IQ has been overestimated in the literature, but remains robust even when accounting for different types of dissemination bias, although reported effects have been declining over time.”

Correlation not Causation: The Relationship between Personality Traits and Political Ideologies“Here we test the causal relationship between personality traits and political attitudes using a direction of causation structural model on a genetically informative sample. The results suggest that personality traits do not cause people to develop political attitudes; rather the correlation between the two is a function of an innate common underlying genetic factor.” – h/t robin hanson!

Generalised Anxiety Disorder – A Twin Study of Genetic Architecture, Genome-Wide Association and Differential Gene Expression“A heritability analysis of the same cohort also confirmed a significant genetic component with h2 of 0.42.” – h/t siberian fox! – and jayman tweeted: “I suspect anxiety is more common in some places than others. Perhaps due to genetic pacification.”

A Unified Crime Theory: The Evolutionary Taxonomy“Drawing on a variety of influences, we argue that many types of crime can be understood in the evolutionary context of human life history. Along these lines, we present a framework capable of explaining different patterns of criminal offending both at the individual level as well as the macro-level.” – from brian boutwell et al.

Resting heart rate and antisocial behavior: An updated systematic review and meta-analysis“Low resting heart rate was associated with higher levels of antisocial behavior…. Results were similar across behaviors, including aggression and violence.” – h/t anthony hoskin!

The association between childhood autistic traits and adolescent psychotic experiences is explained by general neuropsychiatric problems – from amir sariaslan et al. amir tweeted: “The ‘p factor’ explains assoc’s btwn childhood autistic traits and adolescent psychotic experiences.”

The Flynn Effect: IQ Testing Across Space and Time – from steve sailer.

What Extroverts and Introverts Can Learn From Snails“Genes may change a snail’s ‘personality’ and the thickness of its skin (or rather, its shell)”

Dimensional assessment of normal and abnormal personality in adults of the general population: Comparison of ‘five’ and ‘alternative five’ personality models – h/t andrew sabisky! who tweeted: “are normal and pathological personality all part of one continuum?”

So what if grammars don’t help social mobility?“On the Today programme and the New Statesman website, a statistic was quoted showing that grammar schools have a smaller percentage of pupils on free school meals than comprehensives. There are probably many reasons for this, but most likely the largest factor involved is that intelligence is hereditary and social class correlates with IQ; in other words, middle-class kids tend on average to be more intelligent than working-class ones. You could make the system fairer by replacing grammar entrance exams (for which richer parents hire tutors to help their children pass) with straight-up IQ tests, but the number of poorer children would still be disproportionately low. In fact the more social mobility we have over the generations, as everyone seems to want, the more that social class will correlate with intelligence. Richard Herrnstein pointed this out more than four decades ago. Many years earlier, Michael Young warned about this very process in The Rise of the Meritocracy. Social mobility does have its downsides; that’s because intelligence is just another privilege you inherit from mummy and daddy.” – from ed west.

The economic value of Breaking Bad: How misbehavior in school pays off for some kids“Surprisingly, we find evidence that some non-cognitive skills that manifest as childhood misbehavior in the classroom (and are predictive of lower schooling attainment) are also predictive of higher earnings later in life.”

A social science without sacred values“We argue (1) that many social scientists are paranoid egalitarian meliorists; (2) that they are therefore very sensitive to threats to a sacred egalitarian narrative; (3) that this sensitivity may be excessive (at least in the domain of science) and may cause researchers to unfairly reject research that challenges egalitarianism; (4) that this may then lead to the marginalization of individuals who forward controversial theories and/or data; and (5) that these tendencies lead to bias in the social sciences.” – from the winegard bros.

Social Status: Down the Rabbit Hole – h/t billare! who tweeted: “There are two systems of social status: Dominance & Prestige. For what selfish reasons might the latter one evolve?” – this was a really interesting read, btw.

Why Drunk Vegetarians Eat Meat – h/t jonathan haidt! who tweeted: “…esp. health vegs; moral vegs feel more disgust.”

Shame, guilt, and facial emotion processing: initial evidence for a positive relationship between guilt-proneness and facial emotion recognition ability“Guilt-prone people are highly skilled at recognising other people’s emotions.” [via] – w.e.i.r.d. study. pretty small n.

Gamblers, Scientists and the Mysterious Hot Hand“We’re all in the same boat. We evolved with this uncanny ability to find patterns. The difficulty lies in separating what really exists from what is only in our minds.” – h/t claire lehmann!

Dobzhansky and Montagu’s Debate on Race: The Aftermath

The Mutant Genes Behind the Black Death“Only a few genetic changes were enough to turn an ordinary stomach bug into the bacteria responsible for the plague.”

The End of Indian Summer“At first, human rights commissions fought discrimination only in employment and housing, and there was strong resistance to prosecution of people simply for their ideas. This situation changed from the 1970s onward. Human rights took the place in society that formerly belonged to religion, and human rights advocates acquired the immunity from criticism that formerly belonged to the clergy. Discrimination was no longer wrong in certain cases and under certain circumstances. It became evil, and people who condoned it in any form and for any reason were likewise evil.” – from peter frost.

Is Eastern Europe Any More Xenophobic Than Western Europe? – yes. but france is an exception in the west.

bonus: superforecasting conference on october 24th, if you happen to be in or near london: Superforecasting and Geopolitical Intelligence- Who can Predict the Future, and how?

bonus bonus: Did photosynthesis begin 3.2 billion years ago?“Rusty rocks from ancient ocean suggest bacteria produced oxygen far earlier than thought.”

bonus bonus bonus: The Beetle That Eavesdrops on an Ant’s Secret Language“A beetle evolves to ‘listen in’ on ants’ chemical messages to one another, changing the balance of an ecosystem.” [via]

bonus bonus bonus bonus: Ants con others into being their slaves by mimicking their scent

bonus bonus bonus bonus bonus: Sticky situation: maple syrup bandits face Quebec courts for infamous heist“Trials are under way for the 2012 attempt to steal $18m worth of Quebec’s sweetest export – a case that has succeeded in capturing Hollywood’s attention.”

bonus bonus bonus bonus bonus bonus: Pop Culture Pulsar: The Science Behind Joy Division’s Unknown Pleasures Album Cover

and the tweet of the week… (^_^)

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


linkfest: 05/27/14

Quick Questions for Peter and Rosemary Grant“There is widespread misunderstanding about evolution; that it occurs extremely slowly and therefore cannot be studied in a person’s lifetime. This was the view of Charles Darwin. Many biologists and others now know that this is not correct…. The idea that animals as large as birds might evolve before our eyes is not so well known, yet our study in the entirely natural world of Daphne Major island has revealed this does in fact happen when there is a change in the environment, and it takes place over a period as short as a year, and repeatedly.” – h/t billare!

Is DNA Multilingual?“The genetic code has traditionally been viewed as a universal set of instructions, exquisitely tuned to maintain robust stability and allow evolution-sustaining mutations. But the pervasive occurrence of recoded stop codons, and the backchannel crosstalk between microbes and viruses, paints a more intricate picture of multilingual genetic instructions.”

Jelly genome mystery“The uniqueness of this ctenophore’s nervous system leads Moroz and his team to argue that it must have evolved independently, after the ctenophore lineage branched off from other animals some 500 million years ago.”

Genomic divergence in a ring species complex“Ring species provide particularly clear demonstrations of how one species can gradually evolve into two, but are rare in nature…. Here we use genome-wide analyses to show that, although spatial patterns of genetic variation are currently mostly as expected of a ring species, historical breaks in gene flow have existed at more than one location around the ring, and the two Siberian forms have occasionally interbred.” – h/t razib!

Natural selection and infectious disease in human populations“The ancient biological ‘arms race’ between microbial pathogens and humans has shaped genetic variation in modern populations, and this has important implications for the growing field of medical genomics. As humans migrated throughout the world, populations encountered distinct pathogens, and natural selection increased the prevalence of alleles that are advantageous in the new ecosystems in both host and pathogens. This ancient history now influences human infectious disease susceptibility and microbiome homeostasis, and contributes to common diseases that show geographical disparities, such as autoimmune and metabolic disorders.”

High genetic differentiation between populations often driven by classic selective sweeps“‘We demonstrate that while sites of low differentiation represent sampling effects rather than balancing selection, sites showing extremely high population differentiation are enriched for positive selection events and that one half may be the result of classic selective sweeps. Among these, we rediscover known examples, where we actually identify the established functional SNP, and discover novel examples including the genes ABCA12, CALD1 and ZNF804, which we speculate may be linked to adaptations in skin, calcium metabolism and defense, respectively. Conclusions: We have identified known and many novel candidate regions for geographically restricted positive selection, and suggest several directions for further research.'” – @dienekes’.

Mendelian-Mutationism: The Forgotten Evolutionary Synthesis – h/t neuroskeptic! who tweeted: “Did geneticists ‘crack’ the secret of evolution much earlier than believed?”

this one’s for linton!: Why Marrying Your Cousin May Pay Off“In line with previous findings, the researchers found that among non-foraging societies, a couple’s relatedness was linked with having more surviving children. But among foraging societies, the opposite was true: More-closely related spouses had fewer surviving children. Furthermore, the more family intermarriage in a society, the greater the benefit of intermarrying on the number of children couples had. In other words, in societies in which people frequently married their relatives, intermarrying showed a stronger link to having more children.”

The Closest of Strangers“[I]dentical twins who are aunts and uncles invest more in caring for the children of their twins (their ‘genetic’ sons and daughters) than do fraternal twins.”

Why Do Honor Killings Defy the First Law of Homicide? And Will Smaller Families Lead to Fewer Of Them? – h/t tom farsides! – previously: inclusive inclusive fitness.

Genetic and educational assortative mating among US adults“We find that spouses are more genetically similar than two individuals chosen at random but this similarity is at most one-third the magnitude of educational similarity.”

Irish fair skin can be traced to India and the Middle East“A major new US study at Penn State University has found that Europeans’ light skin stems from a gene mutation from a single person who lived 10,000 years ago…. Keith Cheng from Penn State College of Medicine reported that one amino acid difference in the gene SLC24A5 is a key contributor to the skin color difference between Europeans and West Africans…. ‘The mutation in SLC24A5 changes just one building block in the protein, and contributes about a third of the visually striking differences in skin tone between peoples of African and European ancestry, he said…. The mutation, called A111T, is found in virtually everyone of European ancestry. A111T is also found in populations in the Middle East and Indian subcontinent, but not in high numbers in Africans. All individuals from the Middle East, North Africa, East Africa and South India who carry the A111T mutation share traces of the ancestral genetic code. According to the researchers, this indicates that all existing instances of this mutation originate from the same person.” – h/t 23andMe!

The puzzle of European hair, eye, and skin color“The physical appearance of Europeans seems to result from a selection pressure that acted primarily on women and only secondarily on men. This is especially true for highly visible traits on or near the face—the focus of visual attention.” – from peter frost.

The Dark Triad of Personality – special issue of Personality and Individual Differences. – h/t claire lehmann!

Heritability of brain volume change and its relation to intelligence“Human brain volumes change throughout life, are highly heritable, and have been associated with general cognitive functioning…. Results show that changes in volumes of total brain (mean=-6.4ml; -0.5% loss), cerebellum (1.4ml, 1.0% increase), cerebral white matter (4.4ml, 0.9% increase), lateral ventricles (0.6ml; 4.8% increase) and in surface area (-19.7cm2, -1.1% contraction) are heritable (h2=43%; 52%; 29%; 31%; and 33%, respectively). An association between IQ (available for 91 participants) and brain volume change was observed, which was attributed to genes involved in both the variation in change in brain volume and in intelligence. Thus, dynamic changes in brain structure are heritable and may have cognitive significance in adulthood.”

Cognitive abilities amongst the Sámi population“Lapps have an IQ around 100.8 are tilted towards visuospatial ability and away from verbal ability.” – from elijah armstrong, michael woodley the younger, and richard lynn. edit: original paper here on elijah’s blog! (^_^)

The Flynn Effect in a Nutshell – from elijah.

Does brain structure determine your political views?“‘People like to believe that their own political beliefs are rational, that they’re a sensible response to the world around them, so when we come along and say, “Maybe there are these predispositions, influential but perhaps not fully in your conscious awareness,” that’s not the way we like to view our own political beliefs.'” – h/t mr. robert ford!

Sex-Related Neuroanatomical Basis of Emotion Regulation Ability“Behavioral research has demonstrated that males have a higher capability of regulating their own and others’ emotions than females; however, little is known about the sex-specific brain mechanisms involved in emotion regulation ability…. we found the sex differences in the neuroanatomical basis of emotion regulation ability. Males showed a stronger positive relation between emotion regulation ability and regional gray matter volume (rGMV) in the right dorsolateral prefrontal cortex. In contrast, females demonstrated a stronger positive relation between emotion regulation ability and rGMV in an anatomical cluster that extends from the left brainstem to the left hippocampus, the left amygdala and the insular cortex.”

More Maps of the American Nations – from jayman.

Privilege and Morality“Our species isn’t good at nuance. The ‘privilege’ debate will and must take place in a morally charged context. It is not possible to sanitize the discussion by scrubbing it free of moral emotions. That is one of the many reasons why it is so important to understand what morality is and why it exists. It does not exist as a transcendental entity that happened to pop into existence with the big bang, nor does it exist because the Big Man upstairs wants it that way. It exists because it evolved.” – from helian.

Economic Growth & Human Biodiversity“Economic growth in lower-IQ countries does not invalidate either the reality of IQ differences between countries or the persistence of those disparities.” – from pseudoerasmus.

Good Fences: The Importance of Setting Boundaries for Peaceful Coexistence“Switzerland is recognized as a country of peace, stability and prosperity. This is surprising because of its linguistic and religious diversity that in other parts of the world lead to conflict and violence. Here we analyze how peaceful stability is maintained. Our analysis shows that peace does not depend on integrated coexistence, but rather on well defined topographical and political boundaries separating groups, allowing for partial autonomy within a single country. In Switzerland, mountains and lakes are an important part of the boundaries between sharply defined linguistic areas. Political canton and circle (sub-canton) boundaries often separate religious groups. Where such boundaries do not appear to be sufficient, we find that specific aspects of the population distribution guarantee either sufficient separation or sufficient mixing to inhibit intergroup violence according to the quantitative theory of conflict. In exactly one region, a porous mountain range does not adequately separate linguistic groups and that region has experienced significant violent conflict, leading to the recent creation of the canton of Jura.”

Was Territoriality Important in the Pleistocene? A Commentary on Johnson and Toft – @peter turchin’s.

Southern Europe is suspicious: the evolution of trust in the EU – ess and wvs results.

Trust and In-Group Favoritism in a Culture of Crime [pdf] – h/t ben southwood! who tweeted: “Areas in Palermo with high Mafia involvement have lower generalised trust but higher in-group favouritism.”

In dogs’ play, researchers see honesty and deceit, perhaps something like morality – woof!

What is Phonemic Diversity? — And Does It Prove the Out-of-Africa Theory? – h/t james winters!

How a Protestant spin machine hid the truth about the English Reformation“It seems that in 1533, the year of Henry’s break from Rome, traditional Catholicism was the religion of the vast majority of the country. And in most places it was absolutely thriving. It had developed a particularly English flavour, with a focus on the involvement of ordinary people in parish churches, village greens, plays, and pageants – much of which seemed to involve a good deal of community parties, dancing, and drinking. It is true that English religion in the early 1500s was not especially studious or erudite. The people did not spend hours a day in biblical studies, contemplation, and moralising in the manner of the more intense European reformers. But England had a nationally cohesive spirituality that was alive and exuberant, with a distinctly community feel…. The conclusion of this modern grassroots scholarship is that bulldozing the Catholic Church off the face of medieval England was not a ‘bottom up’ revolution in which Henry merely acquiesced to his people’s wishes by throwing off a widely hated foreign domination. To the contrary, it looks increasingly like Henry and his circle imposed the Reformation ‘top down’, unleashing 100 years of deep anger and alienation that was only overcome by sustained politicking and ruthless force.” – h/t william briggs!

bonus: “No Oxygen? No Problem!” Says Squid That Can Shut Down Its Metabolism – h/t kyle hill!

bonus bonus: A Theory on How Flightless Birds Spread Across the World: They Flew There

bonus bonus bonus: Chicken project gets off the ground“Effort aims to unravel the history of bird’s domestication.” – cluck!

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