linkfest – 09/20/15

What Your DNA Says About Medieval History“A new study uses genetic data from living people to trace millennia-old migration patterns…. [M]uch of what Capelli and his colleagues discovered meshed with what historians already knew. For example, among northern Europeans, highest rate of admixing took place ‘around the late first millennium C.E., a time known to have involved significant upheaval in Europe,’ while admixture between north African and southern European populations was dated to a time span ‘consistent with migrations associated with the Arabic Conquest of the Iberian peninsula.’ But there were surprises, too. Most notably, Capelli and his colleagues discovered evidence for an influx of Mongolians into Europe that predated the reign of Ghengis Khan.” – orig. research article: The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape.

Inuit Study Adds Twist to Omega-3 Fatty Acids’ Health Story“A study published on Thursday in the journal Science reported that the ancestors of the Inuit evolved unique genetic adaptations for metabolizing omega-3s and other fatty acids. Those gene variants had drastic effects on Inuit’s bodies, reducing their heights and weights. Rasmus Nielsen, a geneticist at the University of California, Berkeley, and an author of the new study, said that the discovery raised questions about whether omega-3 fats really were protective for everyone, despite decades of health advice. ‘The same diet may have different effects on different people,’ he said…. The researchers found several genetic variants at different locations in the genome that were unusually common in the Inuit, compared with people in Europe or China. Several of these variations occurred within a cluster of genes that direct construction of enzymes called fatty acid desaturases. (The genes are called FADS, for short….) Even more intriguing was the fact that one of these gene variants was present in almost every Inuit in the study. It is much less common in other populations: About a quarter of Chinese people have it, compared with just 2 percent of Europeans. Natural selection is the only known way this gene variant could have become so common in the Inuit. Dr. Nielsen said this adaptation might have arisen as long ago as 20,000 years, when the ancestors of the Inuit were living in the Beringia region, which straddles Alaska and Siberia…. The adaptation did more than just change blood levels of fatty acids, the scientists found. Inuit who carried two copies of the variant gene were on average an inch shorter and 10 pounds lighter than those without a copy.” – orig. research article: Greenlandic Inuit show genetic signatures of diet and climate adaptation. see also Your Genes Are What You Eat from razib.

Height-reducing variants and selection for short stature in Sardinia“[K]nown height-decreasing alleles are at systematically higher frequencies in Sardinians than would be expected by genetic drift. The findings are consistent with selection for shorter stature in Sardinia and a suggestive human example of the proposed ‘island effect’ reducing the size of large mammals.” – h/t andrew sabisky!

Are humans still evolving? Yes, both globally and locally. – from jerry coyne.

5 key facts about the nuclear DNA from Sima de los Huesos“If confirmed, the results will push back the H. sapiens-H. neanderthalensis ancestor beyond 400 KYA. Meyer suggested that the ancestors of H. sapiens could have diverged from the branch leading to neandertals and denisovans 550 K to 765 K years ago. It may be possible that H. sapiens evolved in western Eurasia and later migrated back into Africa. The fossils from Europe, Asia and Africa in the 400 Ka. period are physically very diverse and may represent multiple species, only one of which could be the ancestor of today’s humans. For example, Chris Stringer thinks it may be needed to look at Homo antecessor and not Homo heidelbergensis as our last common ancestor with neandertals.”

New DNA tests on ancient Denisovan people ‘shows them occupying Altai cave 170,000 years ago’“Prehistoric Siberians lived in Denisova Cave earlier than scientists realised – new claim based on state-of-the-art technology.” – h/t paleoanthropology!

Origins, admixture and founder lineages in European Roma“We found a set of founder lineages, present in the Roma and virtually absent in the non-Roma, for the maternal (H7, J1b3, J1c1, M18, M35b, M5a1, U3, and X2d) and paternal (I-P259, J-M92, and J-M67) genomes. This lineage classification allows us to identify extensive gene flow from non-Roma to Roma groups, whereas the opposite pattern, although not negligible, is substantially lower (up to 6.3%). Finally, the exact haplotype matching analysis of both uniparental lineages consistently points to a Northwestern origin of the proto-Roma population within the Indian subcontinent.”

Why I’m sceptical about the idea of genetically inherited trauma“A recent scientific paper claiming that the children of Holocaust survivors showed evidence of inherited stress was deeply flawed – here’s why.”

Population genetic differentiation of height and body mass index across Europe“Here we find that many independent loci contribute to population genetic differences in height and body mass index (BMI) in 9,416 individuals across 14 European countries.”

North-South divide, Japanese style – from dr. james thompson.

Genetics of IQ and lifespan and Genius? Avoid rare functional genes and Heritability of Specific Cognitive Abilities and Schizophrenia and cognitive decline and g for Latinos and White matter efficiency predicts women’s IQ, but not men’s – all also from dr. james thompson!

SNP hits on cognitive ability from 300k individuals – from steve hsu. h/t holtz!

Do smart girls postpone first sex? and Do women find bright men sexy? – and even MORE from dr. james thompson!! whew!

Green Arabia’s key role in human evolution“Scientists have been illuminating the vital role played by the Arabian Peninsula in humankind’s exodus from Africa. Far from being a desert, the region was once covered by lush vegetation and criss-crossed by rivers, providing rich hunting grounds for our ancestors.”

The UK10K project identifies rare variants in health and disease – h/t kevin mitchell!

Genetics of aggressive behavior: An overview – h/t brian boutwell!

Sons of the Soil, Migrants, and Civil War“In nearly a third of ethnic civil wars since 1945, the conflict develops between members of a regional ethnic group that considers itself to be the indigenous “sons of the soil” and recent migrants from other parts of the country.” – h/t whyvert!

It’s finally out: The big review paper on the lack of political diversity in social psychology“Psychologists have demonstrated the value of diversity – particularly diversity of viewpoints – for enhancing creativity, discovery, and problem solving. But one key type of viewpoint diversity is lacking in academic psychology in general and social psychology in particular: political diversity.” – from jonathan haidt.

The genetics of alcohol dependence: Twin and SNP-based heritability, and genome-wide association study based on AUDIT scores – h/t amir sariaslan!

Chronotype Associations with Depression and Anxiety Disorders in a Large Cohort Study – h/t emily deans! who tweeted: “‘Morning people’ less likely to be depressed in this large and relatively thorough observational study.” – (morning people depress me. (~_^) )

The Hormone That Bonds Humans to Dogs – h/t old whig! who tweeted: “Evolutionary change is faster than we think? Case study: oxytocin.”

Does the Gender of Offspring Affect Parental Political Orientation? – h/t ben southwood! who tweeted: “Studies on offspring gender & political orientation plagued by publication bias; actually there’s no relationship.”

Do Angry Birds Make for Angry Children? A Meta-Analysis of Video Game Influences on Children’s and Adolescents’ Aggression, Mental Health, Prosocial Behavior, and Academic Performance“Overall, results from 101 studies suggest that video game influences on increased aggression (r = .06), reduced prosocial behavior (r = .04), reduced academic performance (r = −.01), depressive symptoms (r = .04), and attention deficit symptoms (r = .03) are minimal.” – h/t joseph schwartz!

Ancient campfires show early population numbers [in australia]“ANU archaeologist Alan Williams used radio carbon dating technology to examine charcoal dates from more than 1000 prehistoric campfires and based on this he says populations appear to have increased steadily until 25,000 years ago…. After this initial increase, he says, population levels remained steady or even declined from 25,000 years ago, during the more arid Last Glacial Maximum (25,000 to 13,000 years ago) when temperatures were about ten degrees cooler…. Campfire numbers began to grow again 13,000 years ago when the northern wet season re-emerged.”

Aboriginal ‘memories’ of Australia’s coastline go back more than 7,000 years

History became legend, legend became myth: Crater Lake – h/t razib! who tweeted: “8,000 year old explosion preserved in folk memory of klamath indians?”

Ancient Script Spurs Rethinking of Historic ‘Backwater’“At a temple site in the Republic of Georgia, letters carved in stone could change the way we see the development of writing.”

bonus: Microbiologists Keep Finding Giant Viruses in Melting Permafrost

bonus bonus: Ancient Cats Drove Ancient Dogs to Extinction – woof? (O.O)

bonus bonus bonus: this year’s ig nobel mathematics prize went to the authors of The Case of Moulay Ismael – Fact or Fancy?“Textbooks on evolutionary psychology and biology cite the case of the Sharifian Emperor of Morocco, Moulay Ismael the Bloodthirsty (1672–1727) who was supposed to have sired 888 children. This example for male reproduction has been challenged and led to a still unresolved discussion. The scientific debate is shaped by assumptions about reproductive constraints which cannot be tested directly — and the figures used are sometimes arbitrary. Therefore we developed a computer simulation which tests how many copulations per day were necessary to reach the reported reproductive outcome…. The results indicate that Moulay Ismael could have achieved this high reproductive success. A comparison of the three conception models highlights the necessity to consider female sexual habits when assessing fertility across the cycle. We also show that the harem size needed is far smaller than the reported numbers.” (~_^)

and the tweet of the week!:

https://twitter.com/History_Pics/status/644508143049940992
_____

(note: comments do not require an email. moulay ismael the bloodthirsty!)

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different mutation rates in different human populations

well this seems important! via race/history/evolution notes, an abstract from the society for molecular biology and evolution 2014 conference (in puerto rico! – teh scientists are always good to themselves whenever they can be (~_^) ):

Evidence for different mutation rates across human populations
Ron Do, David Reich
Department of Genetics, Harvard Medical School, Boston, USA

Although mutation rates (per base pair) have clearly changed across primate evolution, many analyses continue to assume that all present-day human populations have the same mutation rates. Recently, William Amos analyzed 1000 Genomes Project and Complete Genomics sequences and found evidence of significantly higher divergence rates on African than on non-African lineages since separation (W. Amos, PLoS One 4, e63048). The detected pattern was strongest in genomic regions of high polymorphism rate, a pattern that the author hypothesized was due to ‘heterozygote instability’, whereby gene conversion events surrounding heterozygous sites increase the mutation rate. To further test this observation, we measured the relative accumulation of mutations in lineages drawn from two different populations, using 25 deep genome sequences generated according to the same experimental protocol using the Illumina technology. We carried out pairwise comparisons of five sub-Saharan African (Dinka, Mandenka, Mbuti, San, Yoruba) and eight Non-African populations (Australian, Dai, French, Han, Karitiana, Mixe, Papuan, Sardinian) on all divergent sites. We observed statistically significant differences in the relative accumulation of mutations for many pairs of African and Non-African populations. Among the strongest differences is significantly more lineage-specific mutations in Mbuti than in Han Chinese (R=1.044, standard error (SE) =0.0015). On average, we observed about 1% more mutations on African lineages compared to Non-African lineages. We also observed some significant differences across non-African populations, with the Han Chinese who have experienced extreme expansions in population size associated with agriculture having more mutations than the Karitiana, a hunter-gatherer population from Amazonia who did not experience such expansions (R=1.015, SE=0.0014). The results are consistent across both European and African segments of the human reference sequence, so are not an artifact of reference sequence bias. Taken together, these results support the view that per-base pair mutation rates may be dynamically and substantially changing across humans.

cool!

wrt to greater number of mutations in african lineages: polygamy (and, therefore, older fathers)? life in the tropics?

(note: comments do not require an email. old san juan. (^_^) )

linkfest – 07/01/13

a day late and (*hbd chick checks her wallet*) … yes, a dollar short!

World’s Oldest Genome Sequenced From 700,000-Year-Old Horse DNA – cool!

Bad Health at the Origins of Agriculture – from henry harpending! see also andrew badenoch from evolvify.

DNA Evidence for Strong Genome-Wide Pleiotropy of Cognitive and Learning Abilities“Genetic correlations were greater than 0.70 between general cognitive ability and language, reading, and mathematics, results that were highly similar to twin study estimates of genetic correlations. These results indicate that genes related to diverse neurocognitive processes have general rather than specific effects.” – via jayman!

Insulin differs between ethnicities, study finds“People have differing abilities to release and react to insulin depending on ethnicity, according to a new study from researchers at Lund University in Sweden, Stanford University and Kitasato University.” – see also previous linkfest.

I Don’t Feel Your Pain“A recent study shows that people, including medical personnel, assume black people feel less pain than white people…. In each experiment, the researchers found that white participants, black participants, and nurses and nursing students assumed that blacks felt less pain than whites.”original research article.

Studying Tumors Differently, in Hopes of Outsmarting Them“[C]ancer: It is an evolutionary disease.”

Accelerating adaptive evolution in humans“In my last post, I noted R.A. Fisher’s argument that a larger population leads to more mutations and greater potential for adaptive evolution. As human populations have undergone massive growth over recent tens of thousands of years, we would expect the evidence of this population growth to show in our genomes. In this post, I point to a couple of papers that look at this evidence.” – from jason collins.

Three-Parent IVF Set to Go Ahead in Britain

Complete mtDNA from Filipino groups – @dienekes’.

Still missing the point – more good stuff from peter frost on stephen jay gould.

The Search for Western Tribalism“Tribalism as clannishness light.” – from staffan!

How Long Can You Wait to Have a Baby?“[M]illions of women are being told when to get pregnant based on statistics from a time before electricity, antibiotics, or fertility treatment. Most people assume these numbers are based on large, well-conducted studies of modern women, but they are not.”

Grandparents effect spotted in British class system“Children’s eventual position in Britain’s class system is closely linked to that of their grandparents, not just their parents, academics say. And where parents have ‘dropped down’ the socio-economic ladder, the so-called ‘grandparents effect’ often pulls them back up, research suggests…. [A]mong men with both parents and grandparents in the highest socio-economic group, 80% stayed in those positions when they were adults. But among men whose parents had been upwardly mobile, only 61% stayed in the group they had been born in to.” – don’t they mean the “regression to the mean effect’? – via jason collins.

Study: People With a Lot of Self-Control Are Happier“Improbably enough, people who are better able to resist impulses report being more satisfied with their lives.”

Clues in the Cycle of Suicide“Every year, suicide peaks with the tulips and lilacs — increasing roughly 15 percent over the annual average to create one of psychiatry’s most consistent epidemiological patterns. It may seem perverse that the period of spring and early summer … should contain ‘a capacity for self-murder that winter less often has.’ Yet it does.”

A Test to Measure How Rational You Really Are – dysrationalia!

Does life have a purpose?“Nobody expects atoms and molecules to have purposes, so why do we still think of living things in this way?”

Study appears to overturn prevailing view of how the brain is wired

Sardinian family’s tip for a long life: minestrone – and good longevity genes! (~_^) – “Luca Deiana, a professor of clinical biochemistry at the university of Sassari in Sardinia, who has studied some 2500 centenarians on the island since 1996, was quoted by Corriere della Sera at the time as saying the longevity of local inhabitants was influenced by genetics along with environmental, nutritional and lifestyle habits.”

Chilean Mummies Reveal Ancient Nicotine Habit“The hair of mummies from the town of San Pedro de Atacama in Chile reveals the people in the region had a nicotine habit spanning from at least 100 B.C. to A.D. 1450.”

Mysterious Pair Buried With Flowers — Oldest Example Yet“The pair — an adult male and an adolescent of undetermined sex — belonged to the primitive Natufian culture, which flourished between 15,000 and 11,600 years ago in an area that is now Israel, Jordan, Lebanon, and Syria.”

bonus: Judge jails depraved sex gang for 95 years after they committed grotesque abuse on girls as young as 11 – good!

bonus bonus: Foreign reporter raped in Tahrir Square – again. see also Arab Spring Unleashes Illiberal Repressive Masses from parapundit.

bonus bonus bonus: The Divided States of America, in 25 Charts“As America approaches its 237th birthday, it’s feeling quite a bit more ‘pluribus’ than ‘unum’…” – gee, i wonder why?

bonus bonus bonus bonus: First Pictures: Peru’s Rare, Unlooted Royal Tomb

bonus bonus bonus bonus bonus: India: If you have casual sex, you are legally married – ruh roh.

bonus bonus bonus bonus bonus bonus: Take the Impossible “Literacy” Test Louisiana Gave Black Voters in the 1960s – it’s not impossible, but it’s not easy either. esp. given that not all of the questions are worded very clearly. =/

bonus bonus bonus bonus bonus bonus bonus: The scientific feud that ended in an execution

bonus bonus bonus bonus bonus bonus bonus bonus: Leeches from the Underworld Don’t Want Your Blood

bonus bonus bonus bonus bonus bonus bonus bonus bonus: Awesome astronomical board game from 1804

(note: comments do not require an email. the tapir’s PREHENSILE penis! good lord.)