see also Not a White Hispanic from steve sailer.
(note: comments do not require an email. the easter bunny!)
“Many were increasingly of the opinion that they’d all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move, and that no one should ever have left the oceans.”
extra-long [insert dongle joke here] linkfest this week since there wasn’t one last sunday (sorry, dog ate it…). note that there (probably) won’t be one next sunday either, ’cause i’ll be too busy hunting for easter eggs…. (^_^)
Common DNA Markers Can Account for More Than Half of the Genetic Influence on Cognitive Abilities – “In the same sample of 3,154 pairs of 12-year-old twins, we directly compared twin-study heritability estimates for cognitive abilities (language, verbal, nonverbal, and general) with GCTA estimates captured by 1.7 million DNA markers. We found that DNA markers tagged by the array accounted for .66 of the estimated heritability, reaffirming that cognitive abilities are heritable. Larger sample sizes alone will be sufficient to identify many of the genetic variants that influence cognitive abilities.” – via race/history/evolution notes.
Genotypes over-represented among college students are linked to better cognitive abilities and socioemotional adjustment – “The present study investigated … genotype frequencies of 284 SNPs covering major neurotransmitter genes in a sample of 478 Chinese college students, comparing these frequencies with those of a community sample (the 1000 Genomes dataset)…. Results showed that 24 loci showed Hardy–Weinberg disequilibrium among college students, but only two of these were in disequilibrium in the 1000 Genomes sample. These loci were found to be associated with mathematical abilities, executive functions, motivation, and adjustment-related behaviors such as alcohol use and emotion recognition.” – via … somebody … can’t remember who. sorry!
Genes and Smarts – from the derb.
Why Bacteria Commit Suicide – “[I]nfected individuals self-destructed before they could spread the virus to others.”
Evolution via Roadkill – “Cliff swallows that build nests that dangle precariously from highway overpasses have a lower chance of becoming roadkill than in years past thanks to a shorter wingspan that lets them dodge oncoming traffic. That’s the conclusion of a new study based on 3 decades of data collected on one population of the birds. The results suggest that shorter wingspan has been selected for over this time period because of the evolutionary pressure put on the population by cars.”
‘Out of Africa’ Story Being Rewritten Again – “Our early human ancestors may have left Africa more recently than thought, between 62,000 and 95,000 years ago, suggests a new analysis of genetic material from fossil skeletons.” – see also Mitochondrial DNA tree calibrated with ancient DNA @race/history/evolution notes and Revised timescale of human mtDNA evolution from dienekes.
Does the Clark-Unz model apply to Japan and Korea? – from peter frost.
Did evolution give us inflammatory disease? – “[S]ome variants in our genes that could put a person at risk for inflammatory diseases such as multiple sclerosis, Crohn’s disease or rheumatoid arthritis, have been the target of natural selection over the course of human history.” – original research article.
Genes may be reason some kids are picky about food – “The study looked at 66 pairs of twins between ages 4 and 7 years old, and found that genes explain 72 percent of the variation among children in the tendency to avoid new foods, while the rest was influenced by environment.”
A Tale of Three Maps – from jayman.
HVGIQ: The Bahamas – from jason malloy.
The Personality of Tribalism – from staffan.
Remembering Stephen Jay Gould: Bully and Boob – from steve sailer.
Assortative mating and shared life history strategy – from mr. mangan.
Uh-Oh… – malcolm pollack on why there’s not so much “diversity” in silicon valley: “It’s because Silicon Valley … *is* a meritocracy — you just can’t fake being good at writing code, solving complex engineering problems, or designing high-tech gadgetry….”
Was inbreeding common among early humans? 100,000-year-old deformed skull adds evidence to theory of ‘very small’ communities – “The discovery adds to growing evidence that early humans inbred often” – prolly because populations were small. see also Abnormalities in Pleistocene Homo from dienekes.
Moral Matter – the neuroscience of morality.
Men programmed to avoid sex with best friends’ wives: study – “Researchers suggest guys may have a biological predisposition against hitting on their best friends’ partners…. A University of Missouri study has found that adult males’ testosterone levels dropped when they were interacting with the marital partner of a close friend.”
Downton Abbey: Earl of Grantham maximizes inclusive fitness – @occam’s razor.
Experts Say Food May Contribute To Anger, Violent Behavior – “Pace and other nutritionists say if you eat plenty of fish, eggs, beans, fruits and green leafy vegetables, you should have the nutrients you need. However, people who tend to eat a diet loaded with processed or packaged foods could find themselves more easily irritated.”
One of Us – animals are people, too.
Text mining uncovers British reserve and US emotion – “An analysis of the digitized texts of English-language books over the past century concludes that, since the 1980s, words that carry emotional content have become significantly more common in US books than in British ones.”
Evolution and Existentialism, an Intellectual Odd Couple – “On the basis of evolutionary existentialism, I would therefore like to suggest the heretical and admittedly paradoxical notion that, in fact, we need to teach more disobedience. Not only disobedience to political and social authority but especially disobedience to some of our troublesome genetic inclinations.” – hmmmm….
Forbidden City – “The left-wing stranglehold on academia.”
bonus: Life found deep under the sea – “Oceanic-crust microbes survive on hydrogen and carbon dioxide.” in other microbial news: Mariana Trench: Deepest ocean ‘teems with microbes’ – “The deepest place in the ocean is teeming with microscopic life, a study suggests.”
bonus bonus: Palestinian Mother Speaks Out About Daughter’s Honor Killing – “[H]onor killing defendants [are] usually given light sentences. Three years in prison was the stiffest in these cases. Life sentences or execution were never a consideration…. Offenders receive reduced sentences pursuant to Article 18 of Penal Code no. 74 of 1936, which is entitled ‘Necessity.’ The article provides for ‘leniency in punishment for crimes that offenders have committed in order to avert consequences, which could cause irreparable damage to their honor, money, or the honor of those such offenders are obliged to protect.'”
bonus bonus bonus: The Hate List – “[T]he [$]PLC’s site explains that it counts counted ‘1,007 active hate groups in the United States in 2012,’ including ‘organizations and their chapters.’ But ‘The Year in Hate and Extremism’ did not make the ‘chapter’ distinction explicit. It is rarely drawn out in the organization’s frequent media appearances, nor was it mentioned in a letter from the SPLC to the Justice Department warning of the growing threat.” – see also What’s hate got to do with it? @bad data, bad!
bonus bonus bonus bonus: Amazing photographs reveal the lost world of the Omo tribes of Ethiopia
bonus bonus bonus bonus bonus: A Tiny Village Where Women Chose to Be Single Mothers – “30 years ago in this bucolic village in northern Vietnam, the fierce determination of one group of women to become mothers upended centuries-old gender rules….”
bonus bonus bonus bonus bonus bonus: Cannibals of the Past Had Plenty of Reasons to Eat People
bonus bonus bonus bonus bonus bonus bonus bonus: Global Internet Porn Habits Infographic – ‘sup finnish people?! and romanians and hungarians (“mom and son”?!)?!
(note: comments do not require an email. double dongle.)
i know, i know — it’s easier to spot inbreeding (or outbreeding) from the presence (or absence) of a lot of long runs of homozygosity (roh) in the genomes of individuals in a population rather than short roh (see for example the central/south and west asians in this post, populations which everyone knows are regular inbreeders), but i haven’t got any data on long roh for separate, sub-populations (like italians vs. europeans), so we’re gonna have to make do with short roh (for now). and anyway, even the amount of short roh is reduced via outbreeding (and increased via inbreeding), so you can use it as a tool to try to work out a population’s mating history. it’s just not as easy/obvious as with longer roh.
so … the map below is taken from Genomic and geographic distribution of SNP-defined runs of homozygosity in Europeans.
the samples come from:
– the rotterdam study – the netherlands
– popgen – northern germany – specifically the schleswig-holstein region (in deutsch if you like)
– the monica augsburg surveys – southern germany – from the city of augsberg and two neighboring counties
– and popres, which, since this is a study of europeans, i presume must mean that the samples came from both the lolipop study in london and the colaus study, lausanne, switzerland — i discussed those two studies in this previous post (scroll down).
again, the problem with taking samples from people living in big cities is that, even if they may be natives of whatever country they happen to live in, they, or some of their recent ancestors, may have migrated to the city — so, who knows, for instance, if the samples from rotterdam tell us anything about rotterdam or even the region of the country in which rotterdam is located. probably tells us something about the dutch, but even then….
these researchers — nothnagel et al. — chose to look at roh that were 1Mb in length. that’s shorter than the 1.5Mb roh as delineated by the researchers who looked at the roh in russian populations. also, nothnagel et al. weighted the average roh in each population according to how much linkage disequilibrium was (estimated to be) present in each population. don’t ask! no, really — don’t ask, because i don’t really understand why they did this. here’s the wikipedia page for linkage disequilibrium. i know that you can have more ld in an inbreeding population and — you guessed it! — less in an outbreeding one. and, of course, other things like bottlenecks can affect how much ld is present in a population. nothnagel et al. found different amounts of ld in the populations in this study and compensated for that, but again i’m not exactly sure why.
anyway … here’s what they found. this map shows the subpopulation averages of the weighted number of roh per individual (the contour lines are guesstimates — educated guesstimates, but still guesstimates):
if you look closely, you’ll see that there’s a sort-of central band of a relatively low average number of roh (between 37-39) that runs from southern england down through beligum/the netherlands (rotterdam) and northeast france, southern germany and switzerland. and, as the researchers observed, and as we saw in the previous post on russia, the numbers of roh increase going northwards and decrease going south. until you get to southern spain and southern italy, southern greece, and (probably) a central spot in the balkans there, all regions where the average number of roh increases again. the researchers suggest that, perhaps, migration from northern africa to the iberian peninsula (that’s the only region for which they offer a possible explanation for this anomaly) explains the longer roh there — presumably they’re thinking of a bottleneck. maybe. but perhaps it’s due to greater historic inbreeding in southern spain — and southern italy and greece and the balkans. some data showing longer roh would help us tell one way or the other.
the researchers, btw, acknowledge that the areas indicated as having very low amounts of roh — colored in the lightest shades of yellow — i.e. northwest spain and eastern europe — are probably artifacts of the interpolation method that they used. also, for all you scots out there (you know who you are! (^_^) ), while i do predict that the average numbers of roh in scotland ought to be higher there than in england, note that there was no data for scotland included in this study, so the shades of the contours up there are wild guesses as well.
i’m quite surprised by the very low levels of roh in romania, but remember that one has to read this map with the underlying north-south differences in numbers of roh in mind, so perhaps the roh in romania really indicates an inbreeding/outbreeding rate in romania that is more like that found in, say, france/germany. dunno. in any event, it’s very interesting.
now i want to compare the average number of roh in eastern europe with western europe. that’s going to be kinda hard to do since 1) the two studies used different roh lengths (1Mb vs. 1.5Mb), and 2) the numbers from this study have been weighted. still, i think we can get at something of a (very!) rough picture by taking the numbers from germany as our starting point and using them to calibrate the results from the two studies. we can do this, i think, since the samples from germany came from the same sources in both studies — the popgen study for northern germany and the monica study for southern germany.
in the russian study, the samples from northern and southern germany were combined, so we only have one number for germany — which was lower than all the results from eastern europe, typically much lower (see map from previous post). the number of roh in the polish sample, for instance, was more than twice that found for the germans. the average number of roh in russia (Rus_HGDP) was also twice that of the germans. czechs, latvians, estonians — all higher than the germans.
now if we work westwards from germany using the results from the study in this post — the english, the dutch (rotterdam), and the swiss are all in the same range as the southern germans, while the southern french have an even lower average number of roh — and the irish (in dublin) and the czechs are in the same range as the northern germans. so all of these populations — and even the spanish and italians — have fewer roh on average than eastern europeans. which is what i would’ve guessed given what we know about the historic mating patterns of europeans beginning in the early medieval period (see mating patterns in europe series below ↓ in left-hand column).
maybe there’s another explanation for this difference between western and eastern europe — and for the apparent differences between central and southern europe. like i said above, a study or two looking at longer roh would help to clear up the picture one way or the other.
previously: russians, eastern europeans, runs of homozygosity (roh), and inbreeding and ibd and historic mating patterns in europe and ibd rates for europe and the hajnal line and runs of homozygosity and inbreeding (and outbreeding) and runs of homozygosity again
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