linkfest – 01/03/ thecurrentyear

The human migration out of Africa left its mark in mutations“The farther from Africa, the more of them there are.” – h/t billare! – see also: Distance from sub-Saharan Africa predicts mutational load in diverse human genomes.

Genomic Evidence Establishes Anatolia as the Source of the European Neolithic Gene Pool“Kum6 shows a strong population continuity with present-day Sardinia. Kum6 expresses connections to the central Eurasian gene pool. Kum6 shares notable affinity with the Iceman, a 5,300-year-old southern European. Genetic affinities to both East and West suggest continuous contact with Anatolia.”

Ancient Irish had Middle Eastern ancestry, study reveals“Genetic researchers find evidence of mass migration to Ireland thousands of years ago.” – see also: Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome. and see also from razib: The Gaels Were from Scythia. and from dienekes: Bronze Age people from Ireland had steppe ancestry and R1b. – (my mtDNA hapologroup [more here] — H13a1a — is rather rare in ireland, but is most common in daghestan and may have arisen there. the parent group H originated in the near east.)

The Residents of Vanuatu, Then and Now“Analysis of skulls in the oldest known cemetery in the South Pacific suggests that the earliest inhabitants of Vanuatu may have descended from Asian and Polynesian populations, while modern residents share more physical similarities with people in Melanesia.”

The evolution of the age at menarche from pre-historical to modern times“Data from skeletal remains suggest that in the Paleolithic female menarche occurred at an age between 7 and 13 years, early sexual maturation being a trade-off for reduced life expectancy. In the classical, as well as in the medieval years, the age at menarche was generally reported to be at about 14 years, with a range from 12-15 years. A significant retardation of the age at menarche occurred in the beginning of the modern times, soon after the industrial revolution, due to the deterioration of the living conditions, most studies reporting menarche to occur at 15-16 years. In the 20th century, especially in the second half of it, in the industrialized countries, the age at menarche decreased significantly, as a result of the improvement of the socioeconomic conditions, occurring between 12-13 years. In the present times, in the developed countries, this trend seems to slow down or level-off.” – h/t neuroskeptic!

Why parenting may not matter and why most social science research is probably wrong and How to Find a Parenting Effect – from brian boutwell! – from the first article: “Whether it’s a study purporting to link some aspect of parenting to child development, or a study intended to link some new diet fad to weight loss, the results are unclear if they did not control for genetics. Lest someone put words into my mouth later, this does *not* mean that every correlation reported by social scientists is the result of correlated genetic influences. The point, however, is that we have spent decades churning out correlations and we have no idea whether the findings were polluted by unmeasured genetic factors. That’s frightening, especially since public policies have been built on some of these potentially illusory correlations. The standard way of doing business in the social sciences ignores genetic influences, and has for years. Be careful which findings you cling to. Most social science research can only reveal associations; which is important, no doubt, but I presume you want to know something about causality also (i.e., if you eat bacon everyday what’s the chance that it’ll *cause* you to get cancer; that sort of thing). To even begin approximating causality (assuming you cannot do an experiment, which you can’t with most social science research), you must account for all confounding factors—genes included.”

Discontinuity in the genetic and environmental causes of the intellectual disability spectrum“[O]ur results suggest that most severe ID is a distinct condition, qualitatively different from the preponderance of ID, which, in turn, represents the low extreme of the normal distribution of intelligence.”

Heritability of autism spectrum disorders: a meta-analysis of twin studies – between 64-91%.

Progress and promise in understanding the genetic basis of common diseases

The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers: The Discordant Twin (DISCOTWIN) Consortium – h/t amir sarislan! who tweeted: “Heritability of Type 2 Diabetes 72% (95% CI: 61–78%).”

Clinical Genetics Has a Big Problem That’s Affecting People’s Lives“Unreliable research can lead families to make health decisions they might regret.”

Schizophrenia and violence“[T]here are startling new results from a large, representative sample of Norwegians [swedes, i think-h.chick], showing that the rate of violence is about 7 times higher in schizophrenics as compared to controls, and 3 times higher for those with bi-polar disorder.” – from dr. james thompson.

How Time Preferences Differ: Evidence from 53 Countries“Time discounting correlates with innovation, environmental protection, innovation, etc.” – h/t rolf degen!

Personality, cognitive/psychological traits and psychiatric resilience: A multivariate twin study“Neuroticism evidenced the largest phenotypic and genetic relationship with resilience, and accounted for nearly all of the phenotypic and genetic variance between resilience and the other traits.”

Polls and Elections Some Folks You Just Can’t Reach: The Genetic Heritability of Presidential Approval“The model is tested using twin data to estimate the genetic heritability of presidential performance evaluations and finds that presidential approval has a strong genetic component.” – h/t andrew sabisky!

Status Decreases Dominance in the West but Increases Dominance in the East“Across two experiments, having high status decreased punishment by American participants but increased punishment by Chinese and Indian participants. Moreover, within each culture, the effect of status on punishment was mediated by feelings of being respected. A final experiment found differential effects of status on punishment imposed by Asian Americans depending on whether their Asian or American identity was activated.” – h/t timothy bates!

Assortative Mating for Educational Level in Parents of Public School Children (N > 7000 Individuals) in the Lagos State, Nigeria“Approximately 61.5 % of the parents had spouses at the same level of education. More mothers than fathers married upward in educational level. The assortative mating coefficients for educational level were .52–.61 across respondents’ classes, .51–.62 across six school districts, and .57 (.55–.59) in the total sample. Overall, these results were very similar to the findings from Western or Asian samples, providing evidence to support the robustness of human mating pattern in educational attainment across different cultures and ethnic groups.”

‘The Bell Curve’ 20 years later: A Q&A with Charles Murray“The lesson, subsequently administered to James Watson of DNA fame, is that if you say it is likely that there is *any* genetic component to the black-white difference in test scores, the roof crashes in on you. On this score, the roof is about to crash in on those who insist on a purely environmental explanation of all sorts of ethnic differences, not just intelligence. Since the decoding of the genome, it has been securely established that race is not a social construct, evolution continued long after humans left Africa along different paths in different parts of the world, and recent evolution involves cognitive as well as physiological functioning.”

Why Some of the Worst Attacks on Social Science Have Come From Liberals“In the halls of social-science academia, where liberals [have a numerical advantage], it’s telling that some of the same sorts of feeding frenzies occur. This should stand as a wake-up call, as a rebuke to the smugness that sometimes infects progressive beliefs about who ‘respects’ science more. After all, what both the Bailey and Chagnon cases have in common — alongside some of the others in Galileo’s Middle Finger — is the extent to which groups of progressive self-appointed defenders of social justice banded together to launch full-throated assaults on legitimate science, and the extent to which these attacks were abetted by left-leaning academic institutions and activists too scared to stand up to the attackers, often out of a fear of being lumped in with those being attacked, or of being accused of wobbly allyship.”

Small families are better for kids, new research says – hmmmm. – see also: The Quantity-Quality Trade-Off And The Formation Of Cognitive And Non-Cognitive Skills.

edge question 2016: What Do You Consider The Most Interesting Recent [Scientific] News? What Makes It Important? – john tooby’s response: The Race Between Genetic Meltdown and Germline Engineering. – h/t steve stewart williams!

Oldest Hoabinhian site discovered in SW China“The oldest Hoabinhian culture, an important technological adaptation by hunter-gatherers to the humid tropical and subtropical environments of southeast Asia some 43,500 years ago, was identified in southwest China’s Yunnan Province. Discovered at Xiaodong Rockshelter, it is the first-ever Hoabinhian site to be found in China, according to a research team at the Yunnan Institute of Cultural Relics and Archaeology.”

Palaeolithic stone tools found in Iranian Kurdistan

bonus: Do Dogs Know Other Dogs Are Dogs?“This is not a philosophical riddle. Despite their highly variable appearance, dogs can recognize each other by sight alone.” – woof!

bonus bonus: Carrie Fisher: I had sex with Princess Leia fans – what happens at comic-con STAYS at comic-con! (~_^) – h/t razib!

and the tweet of the (last) week…! (~_^)

(note: comments do not require an email. carrie fisher. you’re welcome! (~_^) )

Advertisements

linkfest: 06/10/14

Crickets in two places fall silent to survive“To hide themselves from deadly flies, crickets on two Hawaiian islands have evolved an inability to sing. Ten years ago, two years apart, males appeared on Kauai and Oahu with altered wings, which they would normally rub together to chirp and attract females. New findings published in the journal Current Biology show that the wing changes are physically different and arose from separate mutations. This makes the silent crickets a brand new example of ‘convergent evolution’.” – and some really rapid evolution!

Microbes May Drive Evolution of New Animal Species“[S]ymbiosis — a long-term, stable and often beneficial interaction between organisms — could drive two populations apart, the first step in the development of new species. Although the idea has been floating around for nearly a century, it has only recently begun to gain traction in biology. This idea contrasts sharply with the traditional picture of evolution, in which new species emerge either from geological isolation or from a relentless struggle for food and mates. According to this new hypothesis, a host organism’s microbes might trigger changes in mating and reproduction that begin to define two different populations.” – h/t charles!

you gotta read this!: Coincidental Killers“We assume that microbes evolved to attack humans when actually we are just civilian casualties in a much older war…. Many of the pathogens we fear most are mere tourists on the human body. Their real homes are oceans, caves, or soils. To understand them, we need to understand them within their natural ecology. Soil, for example, is an extreme habitat for a microbe: harsh and constantly changing. It can quickly oscillate from flood to drought, from scalding heat to freezing cold, and total darkness to intense solar radiation. It’s rife with other competing microbes, and crawling with hungry predators. We fear lions and tigers and bears; bacteria have to contend with phage viruses, nematode worms, and predatory amoebas. All of these conditions can lead to adaptations that make microbes accidentally suited for life in a human host. We are, after all, just another environment. A thick capsule that shields a microbe from dehydration could also shield it from our immune system. A spore that is adapted for travelling through the air can be easily inhaled into a respiratory tract.”

Genetically identical ants help unlock the secrets of larval fate“A young animal’s genes are not the only genes that determine its fate. The genetic identity of its caretakers matters too…. [A] team led by Serafino Teseo of the University of Paris 13 used the unique aspects of the [clonal] ants’ biology to test the indirect role genes play in shaping the future identity of larvae and whole colonies by looking at the interaction between larvae and adults. They did so by observing the success of two ant clones, A and B, in pure colonies or mixed together into chimeric colonies. They also swapped broods, so A adults raised B larvae and vice versa. It turned out that A and B larvae developed differently depending on whether A or B nurses raised them. Left alone, pure A colonies produced the most young after six generations, making them more successful than B. However, in mixed colonies, B did better because its larvae more frequently turned into large adults that specialize in egg-laying rather than smaller, foraging-focused individuals….” – h/t rolf muertter!

Mitochondrial DNA of first Near Eastern farmers is sequenced for the first time“According to conclusions, genetic affinities have been observed between the mitochondrial DNA of first Neolithic populations and the DNA of first Catalan and German farmers. This suggests that probably Neolithic expansion took place through pioneer migrations of small groups of population. Moreover, the two main migration routes — Mediterranean and European — might have been genetically linked. ‘The most significant conclusion — highlights Eva Fernández — is that the degree of genetic similarity between the populations of the Fertile Crescent and the ones of Cyprus an Crete supports the hypothesis that Neolithic spread in Europe took place through pioneer seafaring colonization, not through a land-mediated expansion through Anatolia, as it was thought until now….’ Other scientific studies had already provided signs of an alternative scenario of Neolithic spread in Europe different from the one through Anatolia. According to Turbón, ‘recent archaeological finds have proved that the Neolithic arrived to Cyprus around 10,600 years ago, some years after the first documentation of agricultural practices in the Near East.’ Architecture and burial models found in Cyprus’ sites are similar to the ones found in the Middle Euphrates basin, ‘that indicates a direct colonisation of these territories,’ highlights the author. ‘Besides, spatial interpolation of radiocarbon dates from different Neolithic sites in the Near East and Europe also suggests a first seafaring expansion through Cyprus,’ he concludes.” – orginal research article.

The Giant Rat of Sumatra and Sardinia and No True Sardinian – from greg cochran.

A twist in Austronesian origins“The Taiwanese origin of Austronesians is widely accepted. A new preprint confirms this theory, but adds a new twist to the story of Austronesian dispersals, as it seems that in their western expansion, Austronesians picked up some Austroasiatic ancestry. This means either that Austroasiatic speakers preceded them in islands where Austronesian languages are now spoken, or that the Austronesians picked up this kind of ancestry in the mainland before settling in the islands.” – from dienekes.

A new allele for blond hair“There is a widespread belief that whatever made Europeans fair-skinned also gave them their unique palette of hair and eye colors. In reality, fair skin has only a weak genetic linkage with either non-black hair or non-brown eyes.” – from peter frost. see also: A molecular basis for classic blond hair color in Europeans.

A Genetic Map of Fireworks in Time“French Canadians and Slavs are both cases of populations which were once relatively modest and began in a narrow delimited region, but now are quite expansive and numerous. In the case of the East Slavs the demographic expansion also entailed the absorption of numerous Uralic tribes, as well as later Turks. And this illustrates one of the major details which I think has characterized the genetic turnover of human populations: phase shifts from a relatively static one defined by isolation by distance gene flow across clinal gradiants, to a rapid expansion of a small subset, and the overlay of this component as a palimpsest over the underlying variation. In some cases the replacement is nearly total, as in the modern United States. In other cases, as among Great Russians, the Slavic affinities of this population, and its association with Poles and other groups are clear, but there was a non-trivial uptake of exogenous segments which might allow for a reconstruction of the prior genetic landscape. These changes occur over short periods, and are bright fireworks against the comparatively static firmament.” – from razib.

Male faces ‘buttressed against punches’ by evolution“A new theory suggests that our male ancestors evolved beefy facial features as a defence against fist fights. The bones most commonly broken in human punch-ups also gained the most strength in early “hominin” evolution. They are also the bones that show most divergence between males and females.” – h/t darwin evolution! – original research article.

Faster eye responses in Chinese people not down to culture“New research from University of Liverpool scientists has cast doubt on the theory that neurological behaviour is a product of culture in people of Chinese origin. Scientists tested three groups – students from mainland China, British people with Chinese parents and white British people – to see how quickly their eyes reacted to dots appearing in the periphery of their vision…. The findings, published in the journal PLoS One, revealed that similar numbers of the British Chinese and mainland Chinese participants made high numbers express saccades, with the white British participants made far fewer. Culturally the British Chinese participants were similar to their white British counterparts and different to the mainland Chinese students.”

Cultural differences in human brain activity: A quantitative meta-analysis“East Asians show enhanced activity underlying mentalizing and emotion regulation. Westerners show enhanced activity underlying self-reflection and emotional responses.”

Race could be a factor in head, neck cancer survival rates“The national survival rates for African-Americans diagnosed with head and neck cancer have not improved in the last 40 years despite advances in the treatment and management of the disease, researchers have found. The researchers suggest that inherent genetic factors in African-Americans may make some tumors resistant to treatments.”

Severe intellectual disability diagnosed by analysis of entire genome“[A]lmost all mental impairments are caused by new mutations that have not yet occurred in father or mother.” – h/t mr. robert ford!

New genes involved in food preferences will revolutionize diets and improve health“The researchers undertook genome wide association studies (GWAS) to try to unravel the genetic basis for certain food preferences. 2311 Italian subjects participated in the discovery step, while 1755 from other European countries and from Central Asia were used in order to further verify the findings. They uncovered 17 independent genes related to liking for certain foods, including artichokes, bacon, coffee, chicory, dark chocolate, blue cheese, ice cream, liver, oil or butter on bread, orange juice, plain yoghurt, white wine and mushrooms. Surprisingly, none of the genes thus identified belonged to the category of taste or smell receptors…. In a second study, the researchers amassed the response of around 900 healthy adults from North Eastern Italy to salt, and related this to a DNA sequence variation found on the KCNA5 gene, known to be related to taste pathways in mammals.”

First direct evidence for human sex pheromones“‘By using dynamic point-light displays that portray the gaits of walkers whose gender is digitally morphed from male to female, we show that smelling androstadienone systematically biases heterosexual females, but not males, toward perceiving the walkers as more masculine. By contrast, smelling estratetraenol systematically biases heterosexual males, but not females, toward perceiving the walkers as more feminine. Homosexual males exhibit a response pattern akin to that of heterosexual females, whereas bisexual or homosexual females fall in between heterosexual males and females. These effects are obtained despite that the olfactory stimuli are not explicitly discriminable. The results provide the first direct evidence that the two human steroids communicate opposite gender information that is differentially effective to the two sex groups based on their sexual orientation.'” – @deric bownds’ mindblog.

Genetic relatedness predicts contact frequencies with siblings, nieces and nephews: Results from the Generational Transmissions in Finland surveys“Individuals have more contacts with full than with half siblings. Individuals have more contacts with nieces/nephews via full than via half siblings. Individuals have more contacts with nieces/nephews via sisters than via brothers.” – h/t jayman!

Beware Armchair Psychoanalysis“‘Behavioral genetic studies have proved beyond a shadow of a doubt that heredity is responsible for a sizable portion of the variations in people’s personalities. Some people are more hot-tempered or outgoing or meticulous than others, and these variations are a function of the genes they were born with as well as the experiences they had after they were born. The exact proportion— how much is due to the genes, how much to the experiences—is not important; the point is that heredity cannot be ignored.'” – from jayman (quoting judith rich harris there).

SD-IE and other differentiation effects in Italy and Spain [pdf] – “SD–IE [strategic differentiation–integration effort] is a strategic differentiation effect present amongst indices of life history (LH), such that persons and populations of slow LH are more differentiated compared to those of fast LH. We found that this phenomenon is present amongst provinces in Italy and Spain, similarly to demonstrations among US states and Japanese prefectures. The average effect size of SD–IE was found to be bigger in Spain and Italy….. In the present study, we test SD–IE using regional-level data for counties in Spain and Italy.”

Is the smart fraction as valuable as previously thought?“‘Consistent with the intellectual class theory advocated by Rindermann and Thompson (2011) and Rindermann et al. (2009), our research findings showed strong evidence that those people that have high IQ are the most relevant influence on economic development. Although our results suggested that all three examined IQ categories promote higher economic growth, the intellectual class has the highest impact followed by the mean ability and non-intellectual classifications. Similarly, the intellectual class also has a highly significant effect on generating technological progress, whereas the influence of the other two groups is immaterial.'” – @dr. james thompson’s blog.

HVGIQ: Burma and HVGIQ: U.S. Virgin Islands – from jason malloy.

Life unworthy of life – post about, as jayman put it, who supports eugenics. – from the awesome epigone.

The Biology of Risk“The state of your body predicts your appetite for financial risk just as it predicts an athlete’s performance. If we understand how a person’s body influences risk taking, we can learn how to better manage risk takers. We can also recognize that mistakes governments have made have contributed to excessive risk taking.”

We can’t ignore the evidence: genes affect social mobility“Why do so many people fail to accept the overwhelming evidence that genes contribute to academic achievement and thereby social status?” – h/t hbd bibliography!

India’s Feudal Rapists

Old chaps? 3,300-year-old trousers found in China may be world’s oldest“Animal-fur menswear found on the bodies of two mummies in Xinjiang province ‘almost the same shape as today’s trousers'”

Grave find may be Western Europe’s earliest false tooth“Archaeologists have identified what could be remains of the earliest false tooth found in Western Europe. The dental implant comes from the richly-furnished timber burial chamber of an Iron Age woman that was excavated in Le Chene, northern France.”

Cat People Are Smarter Than Dog People, New Study Shows – (~_^) – ftr, i like both. i’m not a speciesist!

bonus: Blind cavefish are able to ‘count’“Blind cave-dwelling fish are able to discriminate between different quantities, scientists say…. Researchers say it is the first time non-visual numerical abilities have been shown in fish.” – h/t mo costandi!

bonus bonus: Bees build mental maps to get home“Study suggests the insects do not rely solely on the Sun as a compass…. ‘The surprise comes for many people that such a tiny little brain is able to form such a rich memory described as a cognitive map,’ says co-author Randolf Menzel, a neurobiologist at the Free University of Berlin.”

bonus bonus bonus: Nemo’s Dad Should Have Become His Mom, And Other Lies Children’s Movies Told You – h/t steve stewart williams!

(note: comments do not require an email. “i wandered lonely as a cloud….”)