African pygmies evolved their short stature twice – “In the rainforests of Africa, being small is so helpful that it evolved twice in separate groups. Luis Barreiro of the University of Montreal in Quebec, Canada, and his colleagues identified 16 regions of the genome associated with short stature in the Batwa pygmies of Uganda. They then compared these regions in 169 Batwa and 74 Baka pygmies from West Africa. ‘In both groups, there was greater variation in those regions associated with being short, but no overlap between them,’ says Barreiro. This suggests they evolved their stature independently instead of inheriting the same ‘pygmy genes’ from a common ancestor.”
The strange history of the North American Arctic – “Archaeologists mapping ancient cultures in the North American Arctic — a region spanning present-day Greenland — have long puzzled over how different cultures relate to one another. Now, an unprecedented large-scale genomics study has traced many such cultures to the Paleo-Eskimos, a people who early inhabited the harsh environment continuously for 4000 years, only to vanish mysteriously about 700 years ago. The discovery could change how scientists understand migration patterns in the North American Arctic…. After comparing the ancient and modern genetic data, the researchers found that the Saqqaq and Dorset cultures belonged to one Paleo-Eskimo people, whose genetic lineage continued in the region for more than 4000 years, from 3000 B.C.E. to 1300 C.E., contradicting previous theories that the diverse cultures came from different peoples. The Paleo-Eskimos are genetically distinct from Native Americans and Inuits, which means they represent a separate, later pulse of migration into the New World, says evolutionary geneticist Eske Willerslev of the University of Copenhagen, a co-author of the study. This contradicts previous theories that humans arrived in the Americas in three waves, painting a scenario of four waves instead — the Amerinds, the Na Dene Native Americans, the Paleo-Eskimos, and the Neo-Eskimo Thules…. What intrigues researchers most is why the Paleo-Eskimo lineage disappeared after the late Dorsets, around the same time that Neo-Eskimo Thules expanded rapidly to the Arctic. Archaeologists have found no evidence of violent conflict between the Thules and the Dorsets, but it would be hard to ignore contrasts between the two groups. The whale-hunting Thules lived in large, well-organized villages and boasted advanced technologies such as dog sleds and sinew-backed bows. The Dorsets, on the other hand, lived in small villages of 20 to 30 people and hunted with chipped stone blades. The researchers suspect that the Dorsets might have been pushed out to the fringes of the Arctic, or perhaps annihilated by a disease. ‘It’s just mind-blowing to imagine an entire people who just completely vanished,’ Willerslev says.” — see also Degüello from greg cochran.
Genetic changes transformed wild rabbits into tame bunnies, DNA study reveals – “When humans domesticated wild rabbits and turned them into pet store favorites, they also changed their genome, a study has found…. The domestication of rabbits happened much more recently than that of cattle, sheep, pigs and dogs, which happened between about 15,000 and 9,000 years ago. Monks in monasteries in the south of France first domesticated
northwestern europeans rabbits around 1,400 years ago…. [T]he researches report in the journal Science, small pre-existing genetic variations — sometimes just one letter of DNA code — started to become more common in the animals as they became domesticated. These variations generally didn’t affect the genes themselves, but rather acted on the genome’s regulatory regions, which are in control of whether genes are turned on or off. ‘Wild and domestic rabbits do not differ so much in actual protein sequences, but in how gene and protein expression is regulated,’ says Andersson. Among the genes particularly targeted during domestication were those involved in rabbits’ brains and nervous systems. That’s to be expected, Andersson says, because the differences between domestic and wild rabbits are almost all behavioral, while physical differences are slight…. Domestication of rabbits was made easier because the wild variety is a highly polymorphic species that already possesses many of gene variants selectively enhanced during domestication, the researchers say. That is likely to have been the case with most domesticated species, they say. ‘We predict that a similar process has occurred in other domestic animals and that we will not find a few specific genes that were critical for domestication,’ Andersson says.” — see also: Rabbit genome analysis reveals a polygenic basis for phenotypic change during domestication.
Comparative population genomics in animals uncovers the determinants of genetic diversity – h/t lars penke! who tweeted: “Across species, higher genetic diversity is not predicted by ecology, but by faster life history.”
Genome-wide genotype and sequence-based reconstruction of the 140,000 year history of modern human ancestry — “We investigated ancestry of 3,528 modern humans from 163 samples. We identified 19 ancestral components, with 94.4% of individuals showing mixed ancestry. After using whole genome sequences to correct for ascertainment biases in genome-wide genotype data, we dated the oldest divergence event to 140,000 years ago. We detected an Out-of-Africa migration 100,000–87,000 years ago, leading to peoples of the Americas, east and north Asia, and Oceania, followed by another migration 61,000–44,000 years ago, leading to peoples of the Caucasus, Europe, the Middle East, and south Asia. We dated eight divergence events to 33,000–20,000 years ago, coincident with the Last Glacial Maximum. We refined understanding of the ancestry of several ethno-linguistic groups, including African Americans, Ethiopians, the Kalash, Latin Americans, Mozabites, Pygmies, and Uygurs, as well as the CEU sample. Ubiquity of mixed ancestry emphasizes the importance of accounting for ancestry in history, forensics, and health.” — don’t miss figure 2!
Seals May Have Carried Tuberculosis To The New World — thousand-year-old skeletons from peru suggest seals brought tuberculosis to americas.
Y Chromosomes of 40% Chinese Descend from Three Neolithic Super-Grandfathers – “This observation suggests that the main patrilineal expansion in China occurred in the Neolithic Era and might be related to the development of agriculture.”
Blue Eyes Are More Common Than Any Other Colour in Britain – “The Blue Eyes Project has found that although all eyes in Britain were once brown, they are now 48% blue, 30% green and just 22% brown…. The study mapped eye colour across the UK and Ireland and found that Scottish and Irish people are more likely to have blue eyes than in other parts of the UK, particularly the south. Just over a third (35%) of the population of south-west England and 41% in east England have blue eyes, compared to 57% in southeast Scotland…. Blue eyes are the result of a variant in the HERC2 gene, which, when it mutates, switches off the supply of brown-eye forming melanin, researchers say. Green eyes are also a result of this change, because they arise from a combination of the blue variant with brown. The first gene mutation resulting in blue eyes is understood to have occurred in the Baltic region around 10,000 years ago.”
Admixture in South African Afrikaners — from razib.
Finland’s love of milk dates back to the Stone Age – “A combined team from the Universities of Bristol (England) and Helsinki (Finland) have been examining examples of Corded Ware pottery found in the northern parts of Finland. The pieces examined were cooking pots dated at 3,900 to 3,300 BCE and also approx. 2,500 BCE. Astonishingly the pots from 2,500 BCE contained traces of milk fats. This proved that the inhabitants at that time, despite a climate where it can snow for up to four months of the year, had domesticated animals.”
Holding a Mirror to Their Natures – “[U]nrelated look-alikes showed little similarity in either personality or self-esteem. By contrast, twins — especially identical twins — score similarly on both scales, suggesting that the likeness is largely because of genetics…. Personality traits do not appear to be influenced by the way people are treated because of appearance. Moreover, they found, there appears to be no special bond between look-alikes. Helen Fisher, a biological anthropologist at Rutgers University who is also an identical twin, praised that study, saying it went to the heart of what makes people form a bond. ‘Even in cases where a person is a dead ringer for another, the natural pull is not there,’ Dr. Fisher said, ‘which builds the case that there is an underlying biology to kinship.'” — h/t steve stewart williams!
On the genetic architecture of intelligence and other quantitative traits — from steve hsu. h/t richard harper! who tweeted: “cognitive ability gene search requires sample sizes of 10,000 genes across a million persons.”
Genes Influence Young Children’s Human Figure Drawings and Their Association With Intelligence a Decade Later – “Do genes influence individual differences in this species-typical behavior, and is drawing related to intelligence (g) in modern children? We report on the first genetically informative study of children’s figure drawing. In a study of 7,752 pairs of twins, we found that genetic differences exert a greater influence on children’s figure drawing at age 4 than do between-family environmental differences. Figure drawing was as heritable as g at age 4 (heritability of .29 for both). Drawing scores at age 4 correlated significantly with g at age 4 (r = .33, p < .001, n = 14,050) and with g at age 14 (r = .20, p < .001, n = 4,622). The genetic correlation between drawing at age 4 and g at age 14 was .52, 95% confidence interval = [.31, .75]. Individual differences in this widespread behavior have an important genetic component and a significant genetic link with g." – h/t rosalind arden!
The Canadian IQ calculated from the standardization of the WAIS IV eh? — h/t emil kirkegaard (no relation)!
Differences in cognitive abilities among primates are concentrated on G: Phenotypic and phylogenetic comparisons with two meta-analytical databases – “Using meta-analytic databases of ethological observations of cognitive abilities involving 69 primate species, we found that cognitive abilities that load more strongly on a common factor (which is here termed G, in line with the terminology developed in previous literature to describe aggregated measures of general intelligence) are associated with significantly bigger interspecies differences and bigger interspecies variance. Additionally, two novel evolutionary predictions were made: more G-loaded abilities would present (1) weaker phylogenetic signals, indicating less phylogenetic conservativeness, and (2) faster rates of trait evolution, as it was hypothesized that G has been subjected to stronger selection pressures than narrower, more domain-specific abilities. These predictions were corroborated with phylogenetic comparative methods, with stronger effects among catarrhines (apes and Old World monkeys) than within the entire primate order. These data strongly suggest that G is the principal locus of selection in the macroevolution of primate intelligence. Implications for the understanding of population differences in cognitive abilities among human populations and for the theory of massive modularity applied to intelligence are discussed.” – h/t erwin schmidt!
The Elusive X-Factor, or Why Jonathan Kaplan Is Wrong about Race and IQ – @humanvarieties.
Coevolution of languages and genes – “[E]volutionary processes are more complex than simple models of gene-language coevolution predict, with linguistic boundaries only occasionally functioning as barriers to gene flow. More frequently, admixture takes place irrespective of linguistic differences, but with a detectable impact of contact-induced changes in the languages concerned.” – h/t jayman!
Does Natural Law exist? – “While certain notions of right and wrong can apply to all humans, much of what we call ‘morality’ will always be population-dependent. What is moral in one population may not be in another.” – from peter frost.
Morality: The Amazing Side-Taking Machine – “If there are so many evolutionary pathways to nice behaviors, and if many animals are cooperative, including bees, bats, hyenas, and monkeys, then perhaps the elaborate paraphernalia of human morality — explicit rules of behavior, moral taboos, moral debates, accusations, impartiality, punishments — are not needed to make people nice. Right? This is exactly what psychological research indicates. Developmental evidence shows that children are nice to people before acquiring adult-like moral judgment. Moreover, when children develop moral judgment, it does not prevent them from taking actions they judge wrong such as lying or stealing. In adults, research shows that moral judgments differ from and can even oppose altruistic motives. Research on hypocrisy shows that people are mostly motivated to appear moral rather than to actually abide by their moral judgments. Research on ‘motivated reasoning’ shows that people deviously craft moral justifications to push their own agendas. In short, people can be nice without morality and nasty with morality — altruism and morality are independent. In fact, humans are more eager to judge other people than to follow their own moral advice. Moral condemnation of other people’s behavior is distinctly, perhaps uniquely, human. So, what is the evolutionary function of condemnation…? People can use moral judgment to assess the wrongness of fighters’ actions and then choose sides against whoever was most immoral. When all bystanders use this strategy, they all take the same side and avoid the costs of escalated fighting. That is, moral condemnation functions to synchronize people’s side-taking decisions. This moral strategy is, of course, mostly unconscious just like other evolved programs for vision, movement, language, and so on.”
The roots of human altruism – “[T]he willingness to provision others varies greatly from one primate species to the next. But there was a clear pattern, as summarized by Burkart: ‘Humans and callitrichid monkeys acted highly altruistically and almost always produced the treats for the other group members. Chimpanzees, one of our closest relatives, however, only did so sporadically.’ Similarly, most other primate species, including capuchins and macaques, only rarely pulled the lever to give another group member food, if at all – even though they have considerable cognitive skills. Until now, many researchers assumed that spontaneous altruistic behavior in primates could be attributed to factors they would share with humans: advanced cognitive skills, large brains, high social tolerance, collective foraging or the presence of pair bonds or other strong social bonds. As Burkart’s new data now reveal, however, none of these factors reliably predicts whether a primate species will be spontaneously altruistic or not. Instead, another factor that sets us humans apart from the great apes appears to be responsible. Says Burkart: ‘Spontaneous, altruistic behavior is exclusively found among species where the young are not only cared for by the mother, but also other group members such as siblings, fathers, grandmothers, aunts and uncles.’ This behavior is referred to technically as the ‘cooperative breeding’ or ‘allomaternal care.'”
Feminist activist women are masculinized in terms of digit-ratio and dominance: A possible explanation for the feminist paradox – “The feminist movement purports to improve conditions for women, and yet only a minority of women in modern societies self-identify as feminists. This is known as the feminist paradox…. We measured the 2D:4D digit ratios (collected from both hands) and a personality trait known as dominance (measured with the Directiveness scale) in a sample of women attending a feminist conference. The sample exhibited significantly more masculine 2D:4D and higher dominance ratings than comparison samples representative of women in general, and these variables were furthermore positively correlated for both hands. The feminist paradox might thus to some extent be explained by biological differences between women in general and the activist women who formulate the feminist agenda.”
Global genetic variations predict brain response to faces – “[A] significant proportion of the brain response to facial expressions is predicted by common genetic variance in a subset of regions constituting the face network. These regions show the highest inter-individual variability in the number of connections with other network nodes, suggesting that the genetic model captures variations across the adolescent brains in co-opting these regions into the face network.” – h/t razib!
Brain, behavior and genetics – “Regardless of where the science now lies, we know that biology controls behavior. Our actions and thoughts aren’t magic, they rely on the biochemistry of neurotransmitters and nerve signals. They have physical substrates that are controlled by our genes….”
The impact of neighbourhood deprivation on adolescent violent criminality and substance misuse: A longitudinal, quasi-experimental study of the total Swedish population — “We found that the adverse effect of neighbourhood deprivation on adolescent violent criminality and substance misuse in Sweden was not consistent with a causal inference.” — see also Depraved on account of being deprived? from dr. james thompson.
Honor: The Cause of — and Solution to — All of Society’s Problems – “Centuries-old cultural norms don’t change overnight….” — gee, i wonder why? (where does culture come from?)
Social sciences suffer from severe publication bias – “Survey finds that ‘null results’ rarely see the light of the day.” – h/t claire lehmann!
Haidt: “Political Diversity Will Improve Social Psychological Science” – from steve sailer.
How Do Liberal and Conservative Attitudes About Obedience to Authority Differ? The Surprising Result of My Study — “Together with my collaborators Dr. Danielle Gaucher and Nicola Schaefer, we asked both red and blue Americans to share their views about obeying liberal authorities (e.g., ‘obey an environmentalist’). In an article that we recent published in Personality and Social Psychology Bulletin, we found that liberals were now the ones calling for obedience. And when the authorities were viewed as ideologically neutral (e.g., office manager), liberals and conservatives agreed. Only when people perceived the authority to be conservative (e.g., religious authority) did conservatives show a positive bias.”
Measuring Inbreeding in the Greek Gods — “it seems that Ares has an inbreeding coefficient of 37.5%. This is due to the fact that his parents—Zeus and Hera—are siblings, as well as his grandparents with each other. Zeus has an inbreeding coefficient of 25%.” — (^_^)
bonus bonus: Why are all our wagtails vanishing? Scientists baffled by long-term decline of three species in Britain – “The three wagtail species spotted on our shores are the Yellow Wagtail, a farmland bird that migrates to sub-Saharan Africa, and two which largely remain in the UK over the winter, the Grey Wagtail, a river specialist, and the familiar Pied Wagtail. Researchers said the races of both Pied and Yellow Wagtail breeding in the UK nest almost nowhere else in the world…. Sarah Harris, BBS Organiser at the British Trust for Ornithology, said: ‘I find it fascinating that three seemingly similar birds, the Yellow, Grey and Pied Wagtail can lead such different lives and face such a variety of challenges. With the UK races of two of these species – Pied and Yellow Wagtails – being largely confined to our islands, these population changes are of global conservation significance….'” – ornithologists are soooo waaaaycist! they make me sick! (~_^)
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