Archives for posts with tag: evolution

Deep-ocean microbe is closest living relative of complex cells“A new study indicates that plants, fungi, and animals are descendants of archaea, the group of single-celled organisms that includes Sulfolobus, a resident of hot springs.” – h/t bill barendse! – see also: New Loki Microbe Is Closest Relative To All Complex Life.

A Surprise for Evolution in Giant Tree of Life“Researchers build the world’s largest evolutionary tree and conclude that species arise because of chance mutations — not natural selection…. This controversial proposal stems from efforts by Hedges and collaborators to build the world’s most comprehensive tree of life — a chart plotting the connections among 50,000 species of Earth’s vast menagerie. Their analysis suggests that speciation is essentially random. No matter what the life form — plant or animal, insect or mammal — it takes about 2 million years for a new species to form. Random genetic events, not natural selection, play the main role in speciation.” – see also Was Charles Darwin Wrong About Speciation? from razib.

Genetic changes to basic developmental processes evolve more frequently than thought“Newly evolved genes can rapidly assume control over fundamental functions during early embryonic development. The findings suggest that evolutionary changes to the genetics of fundamental biological processes occur more frequently than previously thought.” – h/t david bachinsky!

The First GMO Is 8,000 Years Old“Scientists find that bacteria modified DNA in sweet potatoes millennia ago.”

Behavioral idiosyncrasy reveals genetic control of phenotypic variability [pdf] – “If we could rear genetically identical individuals from a variety of genetic backgrounds and rear them in the same environment, how much phenotypic variation between individuals of the same genotype would we see? Would different genetic backgrounds differ in their degree of variability? What would account for these differences? We used Drosophila inbred lines to address these questions focusing on variability in locomotor handedness. We show that different genotypes vary dramatically in their propensity for variability, that phenotypic variability itself, as a trait, can be heritable, and that loci affecting variability can be mapped. The genetic control of variability has received little attention in quantitative genetics despite the important role variability plays in explaining phenotypic variation between individuals.”

two tweets from the Biology of Genomes meeting re. a presentation on mutation rates:

Team Characterizing DNA from Ancient Human with Recent Neanderthal Ancestry [registration req.] – see also Ancient DNA from an Upper Paleolithic European with recent Neanderthal ancestry“the male sample, Oase 1, is 37-42K years old and comes from the Pestera cu Oase site in southwestern Romania. it’s estimated to harbor 5-11% of genome-wide Neanderthal ancestry, with as much as 50% on chromosome 12. the admixture is in relatively long stretches, which suggests that the mixture took place four to six generations before Oase 1 was alive. – @the eurogenes blog.

The archaeology, chronology and stratigraphy of Madjedbebe (Malakunanja II): A site in northern Australia with early occupation“The stone artefacts and stratigraphic details support previous claims for human occupation 50–60 ka and show that human occupation during this time differed from later periods.” – h/t chris stringer!

Stone bracelet is oldest ever found in the world“Dating back 40,000 years to the Denisovan species of early humans, new pictures show beauty and craftsmanship of prehistoric jewellery.” – denisovan jewelry!!

The Old Race – from greg cochran.

Ancient DNA Tells a New Human Story“The study of ancient DNA has challenged this view. We now know that mass migrations occurred repeatedly, overwhelming natives while absorbing some of their genes…. Joseph Pickrell of Columbia University and David Reich of Harvard University argue that ‘major upheavals’ of human population have been ‘overwriting’ the genetic history of the past 50,000 years. The result, they say, is that ‘present-day inhabitants of many places in the world are rarely related in a simple manner to the more ancient peoples of the same region.'” – from matt ridley.

2,500-year old Etruscans“All that can be said based on this is that they seem broadly southern European and not particularly Tuscan.” – from dienekes. – h/t anthropology tip!

The time and place of European gene flow into Ashkenazi Jews – @the eurogenes blog.

Symbolic bones and interethnic violence in a frontier zone, northwest Mexico, ca. 500–900 C.E.“Persistent interethnic violence has affected some global regions for centuries…. In the prehispanic Northern Frontier of Mesoamerica, approximately 500–900 C.E., people of different ethnic backgrounds struggled for standing in a shifting sociopolitical landscape. Evidence is consistent with long-term social violence….” – h/t gaetan burgio!

London Conference on Intelligence 2015 Keynote – from dr. james thompson.

NIH bans funding for genetic engineering of human embryos – (>.<)

Three hundred years of low non-paternity in a human population“Here we use this approach to investigate 1273 conceptions over a period of 330 years in 23 families of the Afrikaner population in South Africa. We use haplotype frequency and diversity and coalescent simulations to show that the male population did not undergo a severe bottleneck and that paternity exclusion rates are high for this population. The rate of cuckoldry in this Western population was 0.9% (95% confidence interval 0.4–1.5%), and we argue that given the current data on historical populations we have to conclude that, at least for Western human populations, cuckoldry rate is probably in the range of 1%.” – h/t debbie kennett!

Genius and autism may share genetic link, study finds“Child prodigies and their autistic family members may share a genetic link, according to findings published online for the April issue of Human Heredity.”

Immediate susceptibility to visual illusions after sight onset – h/t laura kelley!

The glass is half full *and* half empty: A population-representative twin study testing if optimism and pessimism are distinct systems“Here, we addressed these questions in a genetically informative sample of 852 pairs of twins. Distinct genetic influences on optimism and pessimism were found. Significant family-level environment effects also emerged, accounting for much of the negative relationship between optimism and pessimism, as well as a link to neuroticism. A general positive genetics factor exerted significant links among both personality and life-orientation traits. Both optimism bias and pessimism also showed genetic variance distinct from all effects of personality and from each other.” – h/t stuart ritchie!

Stanford researchers observe the moment when a mind is changed

Nature or nurture? Are sporting champions born to win? – h/t razib!

Menstrual Cycle Phase Does Not Predict Political Conservatism

Heritability of decisions and outcomes of public goods games

The kind of student you were in elementary school predicts mortality – h/t timothy bates!

The Mask of Sanity Revisited: Psychopathic Traits and Affective Mimicry – h/t claire lehmann! who tweeted: “People with psychopathy can produce highly convincing but fake expressions of feelings.”

Polygyny without wealth: popularity in gift games predicts polygyny in BaYaka Pygmies – h/t steve stewart williams!

The kin selection argument continues, with those denying its importance holding firm. They’re wrong. – from jerry coyne.

Behaviorism and the revival of antiracism – from peter frost.

Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles – hmmmm. really? – see also: What your smile says about where you’re from“If you come from a country of immigrants, you’re more likely to crack a friendly smile on the street. That’s the conclusion of a new study, which may explain why Americans beam more than their Chinese and Russian counterparts.”

Is reading to your kids “unfairly disadvantaging” others? – hahahahahaha! – h/t brian boutwell! who tweeted: “The nonsense that you can believe when you’re convinced that genes don’t matter.” – see also Is having a loving family an unfair advantage?

How uncommon is tickertaping? Prevalence and characteristics of seeing the words you hear – h/t kevin mitchell!

Peter Visscher: Genomics, Big Data, Medicine, and Complex Traits – @steve hsu’s.

Memes are Genes – from evolution theorist. (where do memes come from?) – h/t jayman!

How can our future Mars colonies be free of sexism and racism? – (>.<) #virtuesignalling – h/t ed west!

Paternity Case for a New Jersey Mother of Twins Bears Unexpected Results: Two Fathers – ruh roh!

After Nearly Claiming His Life, Ebola Lurked in a Doctor’s Eye“Before he contracted Ebola, Dr. Ian Crozier had two blue eyes. After he was told he was cured of the disease, his left eye turned green [temporarily].” – whoa.

How music evolves“Statistical analysis of music reveals the truth about its periods of revolution.” – h/t argumatronic!

The Medieval Roots of Our DIY Gun Culture“Forget 3-D printers. The first garage gunsmiths date back to the late Middle Ages.”

When Baltimore Shook With Anger, Here’s What China Saw“Online reaction revealed much about Chinese tension with an influx of African immigrants.” – h/t holtz!

No, there’s no “hate speech” exception to the First Amendment – duh. – from eugene volokh.

bonus: The migration of the eagle hunters – awesome!

(note: comments do not require an email. kazakh eagle hunter!)

a linkfest! =D

Experimental evolution reveals hidden diversity in evolutionary pathways“Our findings show that parallel genetic evolution is strongly biased by constraints and we reveal the genetic bases. From such knowledge, and in instances where new phenotypes arise via gene activation, we suggest a set of principles: evolution proceeds firstly via pathways subject to negative regulation, then via promoter mutations and gene fusions, and finally via activation by intragenic gain-of-function mutations. These principles inform evolutionary forecasting and have relevance to interpreting the diverse array of mutations associated with clinically identical instances of disease in humans.”

Selectionism Strikes Back! – from razib.

Genomes carry a heavy burden“Most people’s DNA contains genetic mutations that are potentially lethal to offspring…. Most people carry one or two genetic mutations that can cause early death or infertility in their offspring….”

World’s oldest stone tools discovered in Kenya“Researchers…say they have found the oldest tools made by human ancestors — stone flakes dated to 3.3 million years ago. That’s 700,000 years older than the oldest-known tools to date, suggesting that our ancestors were crafting tools several hundred thousand years before our genus Homo arrived on the scene. If correct, the new evidence could confirm disputed claims for very early tool use, and it suggests that ancient australopithecines like the famed ‘Lucy’ may have fashioned stone tools, too.”

Neanderthals manipulated the bodies of adults and children shortly after death

Neandertal flutes debunked – @dienekes’.

IQ prediction from structural MRI – from steve hsu. see also: MRI-Based Intelligence Quotient (IQ) Estimation with Sparse Learning.

New brain science shows poor kids have smaller brains than affluent kids – see also: Credit, where credit is due, to Lyndsey Layton and Income, brain, race: Prof Kimberly Noble replies and Howitzer or Katyusha: Reply to Prof Noble at dr. james thompson’s blog. – and see also: In today’s social science, wishing makes it so – from charles murray.

Gene study may explain why some remain quick thinkers“Genetic differences could explain why some people are quicker thinkers in middle age and later life, a study of data from 30,000 people suggests.” – see also: GWAS for executive function and processing speed suggests involvement of the CADM2 gene.

Prediction of brain age suggests accelerated atrophy after traumatic brain injury – h/t stuart ritchie! who tweeted: “Super-cool new paper on how to predict someone’s age just from a brain image (r = .92!)”

National Wealth and IQ at the Edge: American Exceptionalism, East Asian Mediocrity – anatoly karlin’s “big-ass blog on national wealth, IQ, HBD, East Asians, smart fractions, etc.” (~_^)

In the beginning was the Word – dr. james thompson blogs on the recent woodley et al. paper “By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century.”

Born That Way – from greg cochran.

Female Same-Sex Attraction Revisited – from jayman.

Examining the S factor in Mexican states – from emil kirkegaard.

Sex differences and vulnerability: how the male-female divide affects health“[S]ome studies have shown that premature baby girls will grow up to suffer greater language deficits than premature boys, whereas boys exposed to certain prenatal toxins will suffer greater deficits to spatial skills than girls similarly exposed, but because sex differences were never the original focus of the research no one, until Geary, has united these sex specific developmental problems and placed them in evolution’s bigger picture. Geary explains, ‘Sexually selected traits are the first to go; for example, low level exposure to prenatal toxins will affect play in boys but not their IQ: if you don’t measure the right thing you will fail to detect underlying problems.'” – h/t steve stewart williams!

Men up to five times more likely to commit sex crimes than the average male if they have brother or father convicted of a sex offence – h/t claire lehmann! who tweeted: “Survey of 21,566 men convicted of sex crimes from 1973- 2009 has revealed a strong genetic component to sex offending.” – see also: Sexual offending runs in families: A 37-year nationwide study.

Aggressive-Antisocial Boys Develop Into Physically Strong Young Men“We found that males’ antisocial tendencies temporally precede their physical formidability. Boys, but not girls, with greater antisocial tendencies in childhood attained larger increases in physical strength between the ages of 11 and 17. These results support sexual selection theory, indicating an adaptive congruence between male-typical behavioral dispositions and subsequent physical masculinization during puberty.”

Childhood Self-Control and Unemployment Throughout the Life Span: Evidence From Two British Cohort Studies“Analyzing unemployment data from two nationally representative British cohorts (N = 16,780), we found that low self-control in childhood was associated with the emergence and persistence of unemployment across four decades. On average, a 1-SD increase in self-control was associated with a reduction in the probability of unemployment of 1.4 percentage points after adjustment for intelligence, social class, and gender.”

Enlisting in the Military: The Influential Role of Genetic Factors“Given that enlistment in the U.S. military is completely voluntary, there has been a great deal of interest in identifying the various factors that might explain why some people join the military, whereas others do not. The current study expanded on this line of literature by estimating the extent to which genetic and environmental factors explained variance in the liability for lifetime participation in the military. Analysis of twin pairs drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health) revealed that 82% of the variance was the result of genetic factors, 18% of the variance was the result of nonshared environmental factors, and none of the variance was accounted for by shared environmental factors.” – from brian boutwell et al.

Risk of Suicide Among US Military Service Members Following Operation Enduring Freedom or Operation Iraqi Freedom Deployment and Separation From the US Military“Findings do not support an association between deployment and suicide mortality in this cohort. Early military separation (<4 years) and discharge that is not honorable were suicide risk factors.” – h/t michael story!

Verbal ability as a predictor of political preferences in the United States, 1974–2012“[H]igher vocabulary scores are associated with a greater likelihood that people place themselves on the ideological and political spectrum and that they vote in presidential elections, but have only small relationships with liberal-versus-conservative self-identification.”

Do our genes tell us how to vote? Study of twins says they might

On the Malleability and Plasticity of the History of the Blank Slate and 21st Century Moral Philosophy Advances Boldly into the 19th Century – from helian.

More on the younger Franz Boas – from peter frost.

Surnames and Y-Chromosomal Markers Reveal Low Relationships in Southern Spain – ruh roh.

New study finds genetic predisposition for noise-induced hearing loss

New function of obesity gene revealed

The placebome: Where genetics and the placebo effect meet

Chimps That Hunt Offer a New View on Evolution“[A] 10-year study of chimpanzees in Senegal shows females playing an unexpectedly big role in hunting and males, surprisingly, letting smaller and weaker hunters keep their prey. The results do not overturn the idea of dominant male hunters, said Jill D. Pruetz of Iowa State University, who led the study. But they may offer a new frame of reference on hunting, tools and human evolution. ‘We need to broaden our perspective,’ she said.”

Upper Palaeolithic ritualistic cannibalism at Gough’s Cave (Somerset, UK): The human remains from head to toe“Our present analysis of the postcrania has identified a far greater degree of human modification than recorded in earlier studies. We identify extensive evidence for defleshing, disarticulation, chewing, crushing of spongy bone, and the cracking of bones to extract marrow. The presence of human tooth marks on many of the postcranial bones provides incontrovertible evidence for cannibalism.”

Yes, You Can Catch Insanity“A controversial disease revives the debate about the immune system and mental illness.” – pediatric autoimmune neuropsychiatric disorders or “PANDAS”.

Hatfield and McCoy Feud — The Real Thing

Colors help set body’s internal clock“[Mice] use light’s changing color to set their own clocks, a finding that researchers expect will hold for humans, too.”

The Myth of the Angry Atheist“[T]hese results support the idea that people believe atheists are angry individuals, but they do not appear to be angrier than other individuals in reality.”

Flowers Are “Darker” at Lower Latitudes“UV radiation may explain why plants and animals closer to the equator come in darker varieties.”

The Disease That Turned Us Into Genetic-Information Junkies – brief history on tay–sachs disease research.

Antibiotic Resistant Bacteria Could Predate Antibiotics“A South American tribe, called the Yanomami, which was isolated for about 11,000 years prior to 2009, have gut bacteria that carry antibiotic resistance genes, according to new research. The Yanomami’s microbiome is far more diverse than that of Europeans or North Americans, but it also contains antibiotic resistant genes, despite never having had antibiotics. The findings suggest antibiotic resistance predates antibiotics, although it is possible the Yanomami ingested naturally occurring antibiotics in soil at some point.” – see also: The microbiome of uncontacted Amerindians.

Rotherham Worker ‘Told To Give Girls To Abusers’“The ex-protection worker says she repeatedly raised concerns about men taking girls away but her boss told her to ‘let them go’.” – also: State wards being groomed for prostitution by paedophile gangs“Organised gangs of paedophiles are grooming state wards as young as 12 for prostitution. Veteran child protection workers have told the Herald Sun they are powerless to protect the children in their care and that the sexual exploitation of state wards is ‘endemic’…. Victoria Police has set up a taskforce to investigate a gang of Afghani men in Dandenong suspected of preying on teens in care.” – australia now. =/

bonus: Jurassic Park in real life: The race to modify the DNA of endangered animals and resurrect extinct ones“Professor Church has applied a sophisticated and revolutionary ‘gene editing’ technique known as Crispr and has managed to get it working in elephant cells to carry out 14 precise changes to its genome. ‘We are now working on in vitro organogenesis [organ formation] and embryogenesis [embryo formation],’ he told The Independent in an email.”

bonus bonus: Genome Digest – findings from genomes of mountain gorilla, pseudomonas aeruginosa, canary, bird flu strain, and leprosy bacterium.

bonus bonus bonus: Through This Chemical Loop, Dogs Win Our Hearts

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Human evolution tied to a small fraction of the genome“Only about 7.5 percent of the human genetic instruction book shaped the evolution of human traits, a new study suggests. And it’s often not genes, but the how-to instructions for using those genes that are most important, researchers report January 19 in Nature Genetics…. Previously, researchers have mostly looked for evolutionary clues in protein-producing genes because proteins do much of the important work in cells and organisms. Altering a protein may change the way an organism looks or acts. But mutations that alter proteins often are devastating to an organism and therefore aren’t passed on to offspring. Gulko and colleagues found that only 9 percent of the DNA that got evolution’s attention resides in protein-coding parts of the genome that are shared with other species. About 52 percent of the places showing signs of natural selection were in intergenic regions, the stretches of DNA between genes. Another 35 percent were in introns — spacer DNA found within genes but not involved in encoding proteins. Both intergenic regions and introns often contain DNA responsible for controlling gene activity. These findings suggest that human evolution works mostly through changes in how genes are used, rather than by altering genes and the proteins they encode.”

The Wrists of Birds Reveal Evolution Undoing Itself“Contrary to earlier claims, a new study shows that evolution may be reversible.” – previously from greg cochran: Back to the trees.

Kennewick Man was Native American“‘Genetic analysis is still under way in Denmark, but documents obtained through the federal Freedom of Information Act say preliminary results point to a Native-American heritage.'” – from dienekes. see also from razib: Native Americans Are Evolutionarily Elegant“One insight of modern ancient DNA is that there has been a great deal of population turnover over the past ~10,000 years, as well as admixture between disparate lineages. When Kennewick Man died ~9,000 years ago Europeans as we understand them did not exist genetically.”

The Genetic Ancestry of African Americans, Latinos, and European Americans across the United States“Over the past 500 years, North America has been the site of ongoing mixing of Native Americans, European settlers, and Africans (brought largely by the trans-Atlantic slave trade), shaping the early history of what became the United States. We studied the genetic ancestry of 5,269 self-described African Americans, 8,663 Latinos, and 148,789 European Americans who are 23andMe customers and show that the legacy of these historical interactions is visible in the genetic ancestry of present-day Americans. We document pervasive mixed ancestry and asymmetrical male and female ancestry contributions in all groups studied. We show that regional ancestry differences reflect historical events, such as early Spanish colonization, waves of immigration from many regions of Europe, and forced relocation of Native Americans within the US. This study sheds light on the fine-scale differences in ancestry within and across the United States and informs our understanding of the relationship between racial and ethnic identities and genetic ancestry.” – see also: The Fluidity of Race from greg cochran.

Genghis Khan’s genetic legacy has competition“The Mongolian leader left a strong footprint in the Y chromosomes of modern descendants — but he was not the only one.”

Largest-ever autism genome study finds most siblings have different autism-risk genes“In the new study, Dr. Scherer’s team sequenced 340 whole genomes from 85 families, each with two children affected by autism. The majority of siblings (69 percent) had little to no overlap in the gene variations known to contribute to autism. They found that the sibling pairs shared the same autism-associated gene changes less than one third of the time (31 percent). The findings challenge long-held presumptions. Because autism often runs in families, experts had assumed that siblings with the disorder were inheriting the same autism-predisposing genes from their parents. It now appears this may not be true.” – h/t shrikant mantri!

Genetic mutation for metabolic disease identified within an Inuit population“The disease in question, glycogen storage disease type IIIa, is caused by mutations in the AGL gene, leading to less-active glycogen-debranching enzymes. The disorder disrupts the body’s capacity to release sugar from glycogen, resulting in the formation of damaging glycogen deposits…. Glycogen storage disease IIIa affects around one in 100,000 people in North America. However, the researchers estimate that the disorder may affect around 1 in 2,500 people in Nunavik – the homeland of the Inuit in Quebec.” – maybe they should stick to eating seal blubber. srsly!

Admixture in the Americas: Admixture among US Blacks and Hispanics and academic achievement“[W]e see the expected directions and order, for Blacks (who are mostly African), American admixture is positive and European is more positive…. We do not see the expected results per genetic model. Among Hispanics who are 73% European, African admixture has a positive relationship to academic achievement. American admixture is negatively correlated and European positively, but weaker than African. The only thing that’s in line with the genetic model is that European is positive. On the other hand, results are not in line with a null model either….” – from emil kirkegaard.

School“In summary, it very much looks like more years of education are associated with an increase in intelligence test scores, but not anything like as strongly to underlying general intelligence or to underlying basic processing speeds.” – from dr. james thompson.

Genetic Pleiotropy Explains Associations between Musical Auditory Discrimination and Intelligence“[A] large sample of Swedish twins (N = 10,500) was used to investigate the genetic architecture of the associations between intelligence and performance on three musical auditory discrimination tasks (rhythm, melody and pitch). Phenotypic correlations between the tasks ranged between 0.23 and 0.42 (Pearson r values). Genetic modelling showed that the covariation between the variables could be explained by shared genetic influences. Neither shared, nor non-shared environment had a significant effect on the associations. Good fit was obtained with a two-factor model where one underlying shared genetic factor explained all the covariation between the musical discrimination tasks and IQ, and a second genetic factor explained variance exclusively shared among the discrimination tasks. The results suggest that positive correlations among musical aptitudes result from both genes with broad effects on cognition, and genes with potentially more specific influences on auditory functions.” – h/t rosalind arden!

The Role of Parenting in the Prediction of Criminal Involvement: Findings From a Nationally Representative Sample of Youth and a Sample of Adopted Youth [pdf] – “The role of parenting in the development of criminal behavior has been the source of a vast amount of research, with the majority of studies detecting statistically significant associations between dimensions of parenting and measures of criminal involvement. An emerging group of scholars, however, has drawn attention to the methodological limitations — mainly genetic confounding — of the parental socialization literature. The current study addressed this limitation by analyzing a sample of adoptees to assess the association between 8 parenting measures and 4 criminal justice outcome measures. The results revealed very little evidence of parental socialization effects on criminal behavior before controlling for genetic confounding and no evidence of parental socialization effects on criminal involvement after controlling for genetic confounding.” – h/t jayman!

Hospitals Aim to Better Match Blood Donors and Recipients“People fall into one of four main blood groups — A, B, AB and O — and they have a so-called Rh factor that is either positive or negative. But scientists over the last few decades have discovered around 33 blood groups and continue to identify more. Each group also contains multiple variations that go to make up a patient’s exact blood type.”

Ageing research: Blood to blood“By splicing animals together, scientists have shown that young blood rejuvenates old tissues. Now, they are testing whether it works for humans.” – parabiosis. it’s baaaack!

Comparative analysis of the human saliva microbiome from different climate zones: Alaska, Germany, and Africa [pdf] – “Here we analyze the saliva microbiome from native Alaskans (76 individuals from 4 populations), Germans (10 individuals from 1 population), and Africans (66 individuals from 3 populations) based on next-generation sequencing of partial 16S rRNA gene sequences. After quality filtering, a total of 67,916 analyzed sequences resulted in 5,592 OTUs (defined at ≥97% identity) and 123 genera. The three human groups differed significantly by the degree of diversity between and within individuals (e.g. beta diversity: Africans > Alaskans > Germans; alpha diversity: Germans > Alaskans > Africans). UniFrac, network, ANOSIM, and correlation analyses all indicated more similarities in the saliva microbiome of native Alaskans and Germans than between either group and Africans. The native Alaskans and Germans also had the highest number of shared bacterial interactions.”

Tuberculosis genomes track human history“A study of nearly 5,000 samples of Mycobacterium tuberculosis from around the world shows how a lineage of the bacterium that emerged thousands of years ago in Asia has since become a global killer that is widely resistant to antibiotic drugs. Although M. tuberculosis probably first emerged some 40,000 years ago in Africa, the disease did not take hold until humans took to farming…. [T]he common ancestor of all the M. bacterium strains circulating today began spreading around 10,000 years ago in the ancient Fertile Crescent, a region stretching from Mesopotamia to the Nile Delta that was a cradle of agriculture…. But of all the M. bacterium strains circulating today, few strike more fear in public-health officials than the ‘Beijing lineage’. First identified in greater Beijing in the mid-1990s, this lineage now circulates throughout the world and many strains are resistant to drugs that vanquish other types of TB…. Consistent with its name, the Beijing lineage did indeed emerge near north-eastern China…. And it did so around 6,600 years ago, the researchers found, which coincides with archaeological evidence for the beginnings of rice farming in China’s upper Yangtze River valley.” – h/t billare!

Your Friends Know How Long You Will Live: A 75-Year Study of Peer-Rated Personality Traits“To test whether friends’ reports of personality predict mortality risk, we used data from a 75-year longitudinal study (the Kelly/Connolly Longitudinal Study on Personality and Aging). In that study, 600 participants were observed beginning in 1935 through 1938, when they were in their mid-20s, and continuing through 2013. Male participants seen by their friends as more conscientious and open lived longer, whereas friend-rated emotional stability and agreeableness were protective for women. Friends’ ratings were better predictors of longevity than were self-reports of personality, in part because friends’ ratings could be aggregated to provide a more reliable assessment.”

Voluntary Activities and Daily Happiness in the US [pdf] – “This paper analyzes differences in daily happiness between those individuals in the United States who perform voluntary activities during the day, and those who do not…. [T]hose who devote any time to voluntary activities during the day report higher levels of daily happiness than those who do not…. [W]hen the issue of reverse causality is taken into account, we find no differences in daily happiness between volunteers and non-volunteers, which indicates that happier individuals are also more likely to volunteer.” – h/t ben southwood!

Aberrant Gene Expression in Humans“The uniqueness of individuals is due to differences in the combination of genetic, epigenetic and environmental determinants. Understanding the genetic basis of phenotypic variation is a key objective in genetics…. One of our major findings is that private SNPs may contribute to aberrant expression in outlier individuals. These private SNPs are more frequently located in the enhancer and promoter regions of genes that are aberrantly expressed, suggesting a possible regulatory function of these SNPs.”

Recurrent loss of sex is associated with accumulation of deleterious mutations in Oenothera“Sexual reproduction is nearly universal among eukaryotes. Theory predicts that the rarity of asexual eukaryotic species is in part caused by accumulation of deleterious mutations and heightened extinction risk associated with suppressed recombination and segregation in asexual species. We tested this prediction with a large dataset of 62 transcriptomes from 29 species in the plant genus Oenothera, spanning 10 independent transitions between sexual and a functionally asexual genetic system called permanent translocation heterozygosity…. These results confirm that an important advantage of sex is that it facilitates selection against deleterious alleles, which might help to explain the dearth of extant asexual species.” – h/t melissa wilson sayres!

Perceptions Of Required Ability Act As A Proxy For Actual Required Ability In Explaining The Gender Gap – @slate star codex. make sure to read jayman’s comment there! this one, too.

Lewontin wins the Crafoord Prize“The Crafoord Prize for 2015 was awarded to Richard Lewontin and Tomoko Ohta, for their discovery that there was very much more genetic variation that had been expected. Lewontin discovered this using protein gel electrophoresis to study a number of loci in Drosophila. It’s an important result. The problem is, virtually everything he’s said and done since that time has been a pile of steaming ideological crap.” – from greg cochran.

Single Markers Tell You Only a Bit About Individual Ancestry“A new paper in The American Journal of Human Genetics, Estimates of Continental Ancestry Vary Widely among Individuals with the Same mtDNA Haplogroup, tells you something which should be obvious: one marker tells you only so much about individual ancestry. In other words, the history of one gene can only tell you so much about the whole genome. Because mtDNA and Y chromosome* does not recombine you can treat it as one long genetic marker…. But Richard Lewontin’s insight that a great deal of human genetic variation is not partitioned across populations, but within them, applies to mtDNA and the Y chromosomes as well. Where Lewontin’s insight misleads is that using just a few more markers one can obtain relatively robust phylogenetic trees which reflect well the population structure and history of a given species.” – also from razib.

The Economist takes a half step forwards“They do not examine the usual finding that educated parents are more influential than rich parents in supposedly ‘boosting’ intelligence. They leave out the genetic element entirely, and say it is ‘incomes’ which are inherited. If so adoption into a rich household should have massive effects on intellect, but that is not found. If adoption cannot wipe the slate clean, what chance a kindergarten?” – from dr. james thompson.

Gender divide in religious belief, survey suggests“A big gender divide exists between men and women in their 40s in belief in God and life after death, a poll suggests. Of the British men surveyed, 54% said they were atheists or agnostics compared with only 34% of women. The study also showed that Muslims in the survey had the fewest doubts about the existence of God and the afterlife. The research involving more than 9,000 British people born in 1970 was analysed at the University of Essex.” – h/t ed west! who tweeted: “71% of evangelical Christians have no doubts about God’s existence. 33% of Catholics, 16% of Anglicans & Methodists.”

This Woman Can’t Feel Fear“Damage from a rare genetic condition appears to have knocked out the ‘fear center’ in her brain.”

Thumb bones in pre-humans make them more like us, study says“Some of our tree-swinging pre-human ancestors may have been a bit more like us than previously thought, thanks to a tiny section of their thumbs. One key attribute that separates humans from other animals is our opposable thumb, and the way parts of the thumb are structured to allow for a strong yet precise grip that fostered advanced use of tools. It’s what allows us to throw items more precisely, pick guitars and turn a key. And now, thanks to high-tech tools of our own, scientists have determined that a couple million years ago one of our pre-human ancestors had the same human-defining precision grip, even though researchers think of them as little more than upright walking apes, according to a study published Thursday in the journal Science. That supports earlier but controversial evidence that the small-brained Australopithecus africanus fashioned early tools.” – h/t regular ron!

‘Designer babies’ debate should start, scientists say – h/t avi tuschman!

Darwin May Have Experienced Extreme Anxiety

Why Footbinding Persisted in China for a Millennium“Despite the pain, millions of Chinese women stood firm in their devotion to the tradition.”

Thomas Cromwell was the Islamic State of his day“No one can be sure of the exact figure, but it is estimated that the destruction started and legalised by Cromwell amounted to 97% of the English art then in existence. Statues were hacked down. Frescoes were smashed to bits. Mosaics were pulverized. Illuminated manuscripts were shredded. Wooden carvings were burned. Precious metalwork was melted down. Shrines were reduced to rubble.”

bonus: When it comes to speedy evolution, you can’t outpace this lizard’s penis

bonus bonus: FDA Considering Releasing Genetically-Modified Mosquitos In Florida – h/t sam bowman!

bonus bonus bonus: Fish Live Under Antarctica’s Ice Shelf, Where It Seems They Shouldn’t Survive“Biologists expected the seafloor under a glacier to be nearly barren, until life swam into view.”

bonus bonus bonus bonus: This fish lived in peace for 70 million years. Then it met the Army Corps of Engineers.

bonus bonus bonus bonus bonus: All in the (bigger) family“A decade of genetic data and other evidence has persuaded most researchers that insects and crustaceans, long considered widely separated branches of the arthropod family, actually belong together. The new arthropod tree puts hexapods — six-limbed creatures that include insects, springtails, and silverfish — as closer kin to crabs, lobster, shrimp, and crayfish than those ‘standard’ crustaceans are to others such as seed shrimp.”

(note: comments do not require an email. comparing apples and oranges.)

Genetic Variation in the Nuclear and Organellar Genomes Modulates Stochastic Variation in the Metabolome, Growth, and Defense“Systems biology is largely based on the principal that the link between genotype and phenotype is deterministic, and, if we know enough, can be predicted with high accuracy. In contrast, recent work studying transcription within single celled organisms has shown that the genotype to phenotype link is stochastic, i.e. a single genotype actually makes a range of phenotypes even in a single environment. Further, natural variation within genes can lead to each allele displaying a different phenotypic distribution. To test if multi-cellular organisms also display natural genetic variation in the stochastic link between genotype and phenotype, we measured the metabolome, growth and defense metabolism within an Arabidopsis RIL population and mapped quantitative trait loci. We show that genetic variation in the nuclear and organeller genomes influence the stochastic variation in all measured traits. Further, each trait class has distinct genetics underlying the stochastic variance, showing that there are different mechanisms controlling the stochastic genotype to phenotype link for each trait.” – h/t kevin mitchell! who tweeted: Some genomes are ‘noisier’ than others – robustness of developmental outcome is itself a genetic trait.

Evolutionary pattern in the OXT-OXTR system in primates: Coevolution and positive selection footprints“It was previously believed that placental mammals present no variability in oxytocin (OXT). The present study reports novel data on the diversity of OXT and its receptor (OXTR) in primate species, including New World monkeys. Contrary to prior expectations, we found three novel OXT forms and several OXTR nonsynonymous changes not previously described. In the Cebidae family, signals of positive selection were found for an OXT variant at position 8, which is associated with larger litter sizes. We detected positive selection for OXTR forms and report a coevolutionary process between changes in OXT and OXTR.”

Effects of the demographic transition on the genetic variances and covariances of human life history traits“The recent demographic transitions to lower mortality and fertility rates in most human societies have led to changes and even quick reversals in phenotypic selection pressures. This can only result in evolutionary change if the affected traits are heritable, but changes in environmental conditions may also lead to subsequent changes in the genetic variance and covariance (the G matrix) of traits. It currently remains unclear if there have been concomitant changes in the G matrix of life history traits following the demographic transition. Using 300 years of genealogical data from Finland, we found that four key life history traits were heritable both before and after the demographic transition. The estimated heritabilities allow a quantifiable genetic response to selection during both time periods, thus facilitating continued evolutionary change. Further, the G matrices remained largely stable but revealed a trend for an increased additive genetic variance and thus evolutionary potential of the population after the transition.” – h/t ruben c. arslan!

Mapping granny: ancestry inference for admixed individuals“In the December issue of G3: Genes|Genomes|Genetics, Yang et al. describe a method for ancestry inference of admixed individuals that uses a geographic approach to explicitly model some of the messy realities of populations. Testing the new method on data from the Population Reference Sample project, the authors were able to localize the grandparents of admixed Europeans to within around 500 kilometres of their reported ancestry, while simultaneously identifying which segments of each person’s genome were inherited from each ancestor.”

Different neurodevelopmental symptoms have a common genetic etiology“Parents of all Swedish 9- and 12-year-old twin pairs born between 1992 and 2002 were targeted for interview regarding problems typical of autism spectrum disorders, ADHD and other neurodevelopmental conditions (response rate: 80 percent). Structural equation modeling was conducted on 6,595 pairs to examine the genetic and environmental structure of 53 neurodevelopmental problems. One general genetic factor accounted for a large proportion of the phenotypic covariation among the 53 symptoms. Three specific genetic subfactors identified ‘impulsivity,’ ‘learning problems,’ and ‘tics and autism,’ respectively.” – h/t jayman! who tweeted: More evidence for the p-factor. Common genetic factor underlies many mental disorders in study of all Swedish twins.”

Measuring missing heritability: Inferring the contribution of common variants“[T]he most reasonable hypothesis concerning ‘missing heritability’ is simply that larger sample size is required to find the many remaining alleles of small effect. Fisher’s infinitesimal model will turn out to be a good first approximation for most human traits.” – from steve hsu.

Self evident but unexplored – how genetic effects vary over time – from jason collins.

Mendelian and polygenic inheritance of intelligence: A common set of causal genes? Using next-generation sequencing to examine the effects of 168 intellectual disability genes on normal-range intelligence“Despite twin and family studies having demonstrated a substantial heritability of individual differences in intelligence, no genetic variants have been robustly associated with normal-range intelligence to date. This is largely ascribed to the high polygenicity of intelligence, i.e., to its being subject to the effects of a large number of genes of individually small effect. Intellectual disability, on the other hand, frequently involves large effects of single genetic mutations, many of which have been identified…. Using an existing pool of known intellectual disability genes, we constructed a set of 168 candidate genes for normal-range intelligence, and tested their association with intelligence in 191 individuals (aged 5–18) sampled from the high and low ends of the IQ distribution. In particular, we 1) employed exon sequencing to examine the possible effects of rare genetic variants in the 168 genes, and 2) used polygenic prediction to examine the overall effect of common genetic variants in the candidate gene set in a larger sample (N = 2125, mean age 20.4, SD = 14.1). No significant association between the candidate gene set and intelligence was detected.”

IQ and Birth Order Effects: Real? No – from jayman.

Educated parents more important than rich parents“Having a mobile phone, a video recorder and a game computer are associated with lower scholastic ability, and the only substantial positive correlation is with the number of books, and of course the cause may not be the books themselves, but the intellect and character of the families who choose to buy books.” – from dr. james thompson.

The inconsistency of studies of gender differences in cognitive abilities: due to using different methods? – from emil kirkegaard.

Familial Mediterranean fever – from greg cochran.

The etiologic role of genetic and environmental factors in criminal behavior as determined from full- and half-sibling pairs: an evaluation of the validity of the twin method“Heritability estimates for CB from full- and half-siblings closely approximated those found from twins in the same population, validating the twin method.” – h/t ben southwood! who tweeted: “N=1,005,471 study of Swedish siblings and half-siblings (reared together & apart) estimates criminal behaviour is 33-56% heritable.”

Genetic polymorphisms predict national differences in life history strategy and time orientation“Polymorphisms in three genes have been linked to aspects of life-history strategy. National frequencies of these polymorphisms form a strong single genetic factor. The genetic factor is strongly associated with national differences in life-history strategy. This association remains after controlling for national socioeconomic differences.”

Genetic clue points to most vulnerable children“Some children are more sensitive to their environments, for better and for worse. Now Duke University researchers have identified a gene variant that may serve as a marker for these children….” – h/t carlos esteban!

French lesson“Modern France is founded on Western principles of equality, human betterment, and universal morality. Anyone anywhere can become French. That view, the official one, seems more and more disconnected from reality.” – from peter frost.

Is Nothing Sacred? – thosewhocansee on the charlie hebdo killings.

Twin study suggests genetic factors contribute to insomnia in children, teens

Monkeys seem to recognize their reflections“Trained macaques studied themselves in mirrors, fuelling debate over animals’ capacity for self-recognition.”

Insights into hominin phenotypic and dietary evolution from ancient DNA sequence data“Nuclear genome sequence data from Neandertals, Denisovans, and archaic anatomically modern humans can be used to complement our understanding of hominin evolutionary biology and ecology through i) direct inference of archaic hominin phenotypes, ii) indirect inference of those phenotypes by identifying the effects of previously-introgressed alleles still present among modern humans, or iii) determining the evolutionary timing of relevant hominin-specific genetic changes. Here we review and reanalyze published Neandertal and Denisovan genome sequence data to illustrate an example of the third approach.”

A New Antibiotic That Resists Resistance

There is A Scientific Reason That Cold Weather Could Cause Colds“The rhinovirus that most commonly causes colds likes chillier temperatures, where the host’s immune system doesn’t fare so well…. [W]e now know that covering your nose might actually help it stay cold-free, in more than one way.” – yes! fiiiiinally!

Remains of long-dead viruses in our genomes aid our immune response

Skip Your Annual Physical“Regardless of which screenings and tests were administered, studies of annual health exams dating from 1963 to 1999 show that the annual physicals did not reduce mortality overall or for specific causes of death from cancer or heart disease…. [S]creening healthy people who have no complaints is a pretty ineffective way to improve people’s health. If you screen thousands of people, maybe you’ll find tens whose exams suggest they might have a disease. And then upon further tests, you’ll find it is really only a few individuals who truly have something. And of those individuals, maybe one or two actually gain a health benefit from an early diagnosis. The others may have discovered a disease, but one that either would never have become clinically evident and dangerous, or one that is already too advanced to treat effectively. For instance, early detection of most thyroid cancers leads to surgery, but in many cases those cancers would not have caused serious problems, much less death. Conversely, for individuals whose annual exams lead to the diagnosis of esophageal or pancreatic cancer, the early diagnosis might extend the time they know they have cancer but is unlikely to extend their lives.” – h/t jason collins!

Variation in cancer risk among tissues can be explained by the number of stem cell divisions“Some tissue types give rise to human cancers millions of times more often than other tissue types. Although this has been recognized for more than a century, it has never been explained. Here, we show that the lifetime risk of cancers of many different types is strongly correlated (0.81) with the total number of divisions of the normal self-renewing cells maintaining that tissue’s homeostasis. These results suggest that only a third of the variation in cancer risk among tissues is attributable to environmental factors or inherited predispositions. The majority is due to ‘bad luck,’ that is, random mutations arising during DNA replication in normal, noncancerous stem cells.”

Germs May Play Key Role in Wound-Induced Skin Cancer

Race and Police Killings: Additional Thoughts – from robert verbruggen who tweeted: “Three data sets now show that racial disparities in police shootings can be explained by violent crime rates.”

In Search of an Association Between Conception Risk and Prejudice [pdf] – h/t lars penke! who tweeted: “4 large studies (1 pre-reg) by @BrianNosek et al. fail to replicate menstrual cycle effects on racial biases.”

The Strange Inevitability of Evolution“Good solutions to biology’s problems are astonishingly plentiful…. [T]wo crucial things about the RNA sequence space. First, there are many, many possible sequences that will all serve the same function. If evolution is ‘searching’ for that function by natural selection, it has an awful lot of viable solutions to choose from. Second, the space, while unthinkably vast and multi-dimensional, is navigable: You can change the genotype neutrally, without losing the all-important phenotype. So this is why the RNAs are evolvable at all: not because evolution has the time to sift through the impossibly large number of variations to find the ones that work, but because there are so many that do work, and they’re connected to one another.” – h/t billare!

Skeptic’s Guide to Debunking Claims about Telomeres in the Scientific and Pseudoscientific Literature – h/t richard harper!

Mathematicians refute oft-cited ‘diversity trumps ability’ study“‘Diverse groups of people bring to organizations more and different ways of seeing a problem and, thus, faster/better ways of solving it,’ Page told The New York Times in 2008. ‘The reason: the diverse groups got stuck less often than the smart individuals, who tended to think similarly,’ Page said. ‘What the model showed was that diverse groups of problem solvers outperformed the groups of the best individuals at solving problems.’ But Thompson’s paper in the Notices of the American Mathematical Society systematically dismantles Page’s sophistic mathematics.”

Easter Island’s Demise May Have Surprising New Explanation“The downfall of Easter Island may have had more to do with preexisting environmental conditions than degradation by humans….”

13,000 Year Old Cosmic Impact Actually Just a Stone Age House Fire

bonus: Deep bacteria may evolve even without passing genes on“Bacteria living hundreds of metres below the seafloor carry more genetic changes than their peers nearer the surface – even though the deep microbes are unlikely to reproduce and undergo natural selection in its traditional sense…. The results show – for the first time, Briggs thinks – that the bacterial genomes change with depth: the micro-organisms at 554 metres carry more mutations in genes that code for energy-related processes like cell division and biosynthesis of amino acids than are seen in their shallower counterparts…. [I]f you take evolution in its broader sense to mean genetic changes across the population, then it might be occurring even without cell division, says Briggs. That’s because in theory, bacteria in these environments grow so slowly that they may survive for hundreds of thousands of years. Individual bacteria might have begun life at the seafloor before being gradually buried, over a period of thousands of years, as more sediment accumulated at the bottom of the sea. If so, perhaps the bacteria now at 554 metres were rare cells in the initial population that have now come to dominate because the other cells, which didn’t carry their genetic mutations, have all died.”

bonus bonus: Insights into the evolution of longevity from the bowhead whale genome“The bowhead whale (Balaena mysticetus) is estimated to live over 200 years and is possibly the longest-living mammal. These animals should possess protective molecular adaptations relevant to age-related diseases, particularly cancer. Here, we report the sequencing and comparative analysis of the bowhead whale genome and two transcriptomes from different populations. Our analysis identifies genes under positive selection and bowhead-specific mutations in genes linked to cancer and aging. In addition, we identify gene gain and loss involving genes associated with DNA repair, cell-cycle regulation, cancer, and aging. Our results expand our understanding of the evolution of mammalian longevity and suggest possible players involved in adaptive genetic changes conferring cancer resistance. We also found potentially relevant changes in genes related to additional processes, including thermoregulation, sensory perception, dietary adaptations, and immune response.”

bonus bonus bonus: A Museum’s Butterfly Emerged Half Male, Half Female“The rarity is like a natural experiment that tells scientists how genes and hormones interact to produce different sexes.”

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

look! another linkfest! (^_^)

Our Cats, Ourselves“Which brings us to the genome of one critical tame animal: ourselves, humans. The Nobel Prize-winning zoologist Konrad Z. Lorenz once suggested that humans were subject to the same dynamics of domestication. Our brain and body sizes peaked during the end of the last ice age, and declined with the spread of agriculture…. Our cultural flexibility and creativity since the end of the ice age have not freed humans from evolutionary forces, but have opened up novel and startling paths. Thinking of domestication as an evolutionary process that occurs through ‘artificial’ selection creates a false dichotomy of nurture and nature that plays into a conceit of human exceptionalism. In fact, the idea that we are apart from nature, that it is ours to tame and exploit, is an outmoded approach. A more useful interpretation is that over the past 10,000 years, humans fashioned their own ecosystem. We were part of a natural process that altered the landscape…. The same forces that reshaped the genomes of our domesticates also reshaped ours.” – from razib. in the new york times! (^_^)

Ancient Easter Islanders Interbred With Native Americans“According to the recent study conducted by geneticists, the ancient inhabitants of Easter Island met and interbred with Native Americans long before Westerners arrived…. The recent genetic study is published on Thursday in the Current Biology journal. According to the study, these ancient people had significant contact with Native Americans hundreds of years ago, before the westerners reached the Island in 1722…. The finding of the study suggests that the intermixing occurred 19 to 23 generations ago. The researchers said that the Polynesian people (Rapa Nui’s) are not believed to have started mixing with Europeans until much later, the 19th century. Malaspinas said the genetic ancestry of today’s Rapa Nui people is roughly 75% Polynesian, 15% European and 10% Native American.”

Barley fuelled farmers’ spread onto Tibetan plateau“Cold-tolerant crop enabled high-altitude agriculture some 3,600 years ago”

Faster than Fisher“[M]igration and conquest, must explain the wide distribution of many geographically widespread selective sweeps and partial sweeps. They were adaptive, all right, but expanded much faster than possible from purely local diffusion.” – from greg cochran.

The Germ of Laziness – also from greg cochran.

Putting IBD to Bed – from razib.

The Red Queen Model of Recombination Hotspots Evolution in the Light of Archaic and Modern Human Genomes – h/t mwpennell! who tweeted: “Recombination hotspots in humans appear to be young…evidence for Red Queen theory for evolution of recombination?”

Inclusive fitness and sexual conflict: How population structure can modulate the battle of the sexes – h/t rebecca sear!

Do Chinese people get bored less easily?“Advanced farming — intensive land use, task specialization, monoculture — has profoundly shaped East Asian societies, particularly China. This is particularly so for rice farming. Because the paddies need standing water, rice farmers must work collectively to build, dredge, and drain elaborate irrigation networks. Wheat farming, by comparison, requires no irrigation and only half as much work. Advanced farming seems to have favored a special package of predispositions and inclinations, including greater acceptance of monotony. This has been shown in two recent studies.” – from peter frost.

Culture and state boredom: A comparison between European Canadians and Chinese“European Canadians (vs. Chinese) are more likely to experience state boredom.” – h/t erwin schmidt!

Gender differences in preferences, choices, and outcomes: SMPY longitudinal study“The figures show significant gender differences in life and career preferences, which affect choices and outcomes *even after ability is controlled for*…. According to the results, SMPY men are more concerned with money, prestige, success, creating or inventing something with impact, etc. SMPY women prefer time and work flexibility, want to give back to the community, and are less comfortable advocating unpopular ideas. Some of these asymmetries are at the 0.5 SD level or greater.” – from steve hsu.

Are liberals and conservatives differently wired? – also from peter frost.

Detecting ‘polygenes’ using signals of polygenic selection. Tools for increasing the power of GWAS – from davide piffer who tweeted: “Watson and Venter’s genomes have higher frequency of intelligence polygenenes.”

Intelligence lost at 1.23 IQ points per decade“Michael Woodley of Menie spends much of his time tending his ancestral estate, pacing the linen-fold panelled rooms of the ancient house, warming his hands at the towering stone fireplace and meditating on the collapse of the aristocracy, the paucity of contemporary innovation and the lamentable and persistent downward drift of the national intellect. Now he sends me a barefoot runner with his latest manuscript, which I have read as the autumn mists creep across the Nadder valley, before penning this reply for the poor urchin to carry back to his master. Young Woodley avers that, not only are we going to hell in a handcart, but we are doing so at a pace which he can predict with some accuracy (1.23 IQ points per decade), composed as it is of two dysgenic effects: the dull have been reproducing with greater fecundity than the bright (.39), and increasing paternal age has increased the rate of deleterious mutations (.84).” – from dr. james thompson.

Gypsy intelligence – also from dr. james thompson.

Lower Body Symmetry and Running Performance in Elite Jamaican Track and Field Athletes – h/t keith laws! who tweeted: “More symmetrical knees & ankles in Elite Jamaican track and field athletes…Of course…”

Great Ape Origins of Personality Maturation and Sex Differences: A Study of Orangutans and Chimpanzees

The Case Against Early Cancer Detection“[C]ancer screening may harm more people than it helps.” – h/t jason collins!

In the U.S., Few Heavy Drinkers Are Actually Alcoholics“About 90 percent of people who drink excessively — more than eight drinks a week for women, 15 for men — are not alcohol dependent.” – h/t ray sawhill!

Genes tell new story: Alcohol in moderation only benefits 15% of population“An alcoholic beverage a day, especially wine, is widely believed to help keep heart disease risk low, but new research from the University of Gothenburg shows that only about 15% of the human population — those with a specific the form of the cholesteryl ester transfer protein (CETP) gene — actually gain this benefit from moderate alcohol consumption.”

The Real Roots of Midlife Crisis“What a growing body of research reveals about the biology of human happiness — and how to navigate the (temporary) slump in middle age.”

Despite its problems, the United States of America is still the best. Thing. Ever.“Other aspects of America’s story, though, seem less important now that the quest for racial equality has become almost a religious mission; this week I finally got around to watching the HBO series John Adams, which begins with the Massachusetts lawyer defending Captain Thomas Preston, the officer blamed for the Boston massacre. The mob wanted to avenge the deaths but, this being a colony where people passionately believed in their ancestral English liberties, ‘due process’ was followed – a term that dates back to the Parliament of Edward III but was obviously influenced by Clause 39 of the Magna Carta. Due process is what was followed in the Ferguson case, but maybe that’s just a boring old racist Anglo-Saxon idea that we can forget about now (grand juries are literally Anglo-Saxon, dating back to the reign of Ethelred II, or possibly the vibrant culturally-enriching Viking maniac King Canute).” – from ed west.

Children are not science projects“What do we tell to prospective adoptive parents? The first answer, and the only answer that ultimately counts, is that they are doing the Lord’s work. They have the opportunity to provide love and nurturing to a child who needs it. There are few better things that human beings can do with their time. The second answer is that they, like biological parents, are not miracle-workers. They will be unable to mold the child. Sometimes their adopted child will experience problems that are not the adoptive parents’ fault; sometimes they will reveal gifts of talent and character that are equally not to the adoptive parents’ credit. What is to the credit of good parents, adoptive and biological alike, is enfolding the child in love.” – from charles murray…who’s really just a big softie after all. (^_^) — see also: Adopt a child, but discard an illusion from dr. james thompson.

In Northern Ireland, a Wave of Immigrants Is Met With Fists – which came (or *should’ve* come) as a surprise to absolutely no one….

When exactly did the Industrial Revolution start?

Europe’s Bronze Age Collapse Not Caused by Climate Change

How Thanksgiving, the ‘Yankee Abolitionist Holiday,’ Won Over the South

Your Inner Feather“About 300 million years ago, our ancestors began to lay hard-shelled eggs. Those early animals would give rise to mammals, reptiles, and birds (collectively known as amniotes, named for the amniotic egg). Edwards and his colleagues found that the first amniotes already had the *entire* complement of feather patterning genes. That means you, as an amniote, have them too.” – cool!

Viruses as a Cure

Stop eating cats and dogs say animal rights campaigners in Switzerland“Cat appears on traditional Christmas menus in some areas of Switzerland.” – wait. what?!

bonus: Snakes are ‘righties’ — with their penis, that is

bonus bonus: Snakes Leave Identity Within Their Fang Marks“Getting a DNA swab from the fang marks of a snake bite can accurately identify the type of snake, a team working in Nepal has found.”

bonus bonus bonus: Monterey Bay researchers capture rare deep-sea anglerfish on video for first time – whoa!

bonus bonus bonus bonus: Ants Regularly Pack Up and Dig New Nests, and Nobody Knows Why

bonus bonus bonus bonus bonus: Red Baron’s WWI German Fokker triplane rebuilt by flying enthusiast – oooo! pretty. (^_^)

(note: comments do not require an email. a face only a mother could love. maybe.)

look! a linkfest! (^_^)

Bayesian analyses of Yemeni mitochondrial genomes suggest multiple migration events with Africa and Western Eurasia

37,000-year-old Russian skeleton has Neanderthal DNA that’s gone missing“Sequences present in its genome haven’t been found in modern human populations.” – see also Remix from greg cochran. – see also Genome of Kostenki-14, an Upper Paleolithic European (Seguin-Orlando, Korneliussen, Sikora, et al. 2014) from dienekes.

Humans Would Beat Neanderthals in Marathon

Different Ways to Color a Cat – from razib. – h/t billare! who tweeted: “Progenitors of modern Europeans were fairly light-skinned–why did a 2nd bout of selection leave its tell-tale marks?”

Admixture in the Americas: Introduction, partial correlations and IQ predictions based on ancestry – from emil kirkegaard.

Our Futile Efforts to Boost Children’s IQ“How can parenting and socioeconomic status play such minor roles in determining IQ, when scholars on all sides of the nature-nurture debate agree that somewhere around half of the variation in IQ is environmental? The short answer is that the environment that affects IQ doesn’t consist of the advantages that most people have in mind — parents who talk a lot to their toddlers, many books in in the house for the older children, high-quality schools and the like. Instead, studies over the past two decades have consistently found that an amorphous thing called the “nonshared” environment accounts for most (in many studies, nearly all) of the environmentally grounded variation. Scholars are still trying to figure out what features of the nonshared environment are important. Peers? Events in the womb? Accidents? We can be sure only of this: The nonshared environment does not lend itself to policy interventions intended to affect education, parenting, income or family structure.” – from charles murray. – h/t mr. mangan, esq!

Results of a “GWAS Plus:” General Cognitive Ability Is Substantially Heritable and Massively Polygenic – h/t emil kirkegaard!

Does neural crest development drive domestication syndrome?“Altered neural crest development could be the reason mammals change in oddly consistent ways during domestication. As first noted by Darwin more than 140 years ago, domestic mammals tend to share certain characteristics—a suite of traits called the domestication syndrome.”

‘Darwin’s Dilemma’ May Be Solved“Scientists following two different lines of evidence have just published research that may help resolve ‘Darwin’s dilemma,’ a mystery that plagued the father of evolution until his death more than a century ago. Biologists and geologists have been puzzled for decades over why life began so early on this planet, and then took so long to get interesting.”

A new study pieces together the puzzle of insect evolution“A new study of insect evolution — the largest of its kind ever undertaken — has uncovered some surprising new information, confirmed some long-held hypotheses and may lead researchers toward a more comprehensive understanding of evolution. One hundred scientists from 10 countries worked together to examine 144 insect species. Their goal was to create an insect ‘family tree’ and establish a timeline of insect evolution. Their results were published recently in the journal Science.” – cool!

More evidence that certain versions of some genes can encourage violence

Facial structure predicts goals, fouls among World Cup soccer players“The scientists studied the facial-width-to-height ratio (FHWR) of about 1,000 players from 32 countries who competed in the 2010 World Cup. The results, published in the journal Adaptive Human Behavior and Physiology, showed that midfielders, who play both offense and defense, and forwards, who lead the offense, with higher FWHRs were more likely to commit fouls. Forwards with higher FWHRs also were more likely to score goals or make assists.”

Mental health: Depression needs large human-genetics studies“To understand the molecular mechanisms of depression, collect genetic data from more than 100,000 people, says Steven Hyman.”

Geneticists tap human knockouts“On average, every person carries mutations that inactivate at least one copy of 200 or so genes and both copies of around 20 genes.”

The Inexorable Progress of Science: Archaeology“With a very limited set of clues, smart guys managed to get key facts about European prehistory roughly correct almost 90 years ago . With tremendously better tools, better methods, vastly more money, more data, etc, archaeologists (most of them) drifted farther and farther from the truth.” – from greg cochran.

How Your Facebook Updates Reveal Your Personality“Extroverts tend to use words like love, tonight, party, excited and amazing. Several length variants of the word soooo and ‘text speak’ terms like lovin and ur, are more often found on extroverts’ updates. In general the extrovert word cloud is sloppy enough to make any ‘Grammar Nazi’ red in the face. When we come to introverts, use of the word computer was one of the biggest giveaways. Posting status updates about Internet, and to a lesser extent anime, doctor who, and books, were also predictive of introversion.” – from neuroskeptic.

The contribution of additive genetic variation to personality variation: heritability of personality“[W]e found that approximately 52% of animal personality variation was attributable to additive genetic variation.”

The genetics of impulsivity: evidence for the heritability of delay discounting – h/t ben southwood! who tweeted: “Impulsivity is 55% heritable at age 18.”

We are not equally empathic – from peter frost.

He’s Definitely a Liberal—Just Check Out His Brain Scan“[W]e’ve had solid indications for a while now that our ideological biases are based, in large part, on the biology of our brains…. Of course, we’d like to think we came to our core beliefs through a process of rational reflection and discussion — or, at the very least, as a psychological reaction to the influence of our parents and peers…. But the profound influence of basic brain biology has just been re-affirmed in a new research paper, which found liberals and conservatives can be easily identified through fMRI scans…. ‘Remarkably,’ writes a team led by P. Read Montague of the Virginia Tech Carilion Research Institute, ‘brain responses to a single disgusting stimulus were sufficient to make accurate predictions about an individual subject’s political ideology.'”

The Most Heritable Gut Bacterium is… Wait, What is That?“By studying 416 pairs of British twins, Julia Goodrich and colleagues from Cornell University have identified the gut microbes whose presence is most strongly affected by our genes.”

Microbiome science threatened by contamination“Non-sterile sequencing returns rogue results in dilute microbe samples.”

Global IQ and health – from dr. james thompson.

Book Review: The Ten Thousand Year Explosion (2009) by Greg Cochran and Henry Harpending – from staffan.

The ecology of religious beliefs“Both comparative and experimental evidence indicate that beliefs in moralizing high gods promote cooperation among humans, a behavioral attribute known to correlate with environmental harshness in nonhuman animals. Here we combine fine-grained bioclimatic data with the latest statistical tools from ecology and the social sciences to evaluate the potential effects of environmental forces, language history, and culture on the global distribution of belief in moralizing high gods (n = 583 societies). After simultaneously accounting for potential nonindependence among societies because of shared ancestry and cultural diffusion, we find that these beliefs are more prevalent among societies that inhabit poorer environments and are more prone to ecological duress.”

Edvard Westermarck on Morality: The Light Before the Darkness Fell and Post-Darwinian, “Evolutional” Theories of Morality in the 19th Century – from helian.

Genes contribute to behavior differences between fierce and friendly rats“Genes active in the brain implicated in differences in rats selected for aggression or tameness”

Intimidating chimpanzee males are more likely to become fathers – ruh roh. – h/t steve stewart williams!

Marriage Records Reveal Patterns of Korean Migration Through the Centuries

What Edward Luttwak Doesn’t Know About Ancient China (Or a Short History of Han-Xiongnu Relations), pt. 1 and What Edward Luttwak Doesn’t Know About Ancient China (Or a Short History of Han-Xiongnu Relations), pt. 2 – from t.greer.

There’s Something About Teutonics – from those who can see.

An extremely low-density human population exterminated New Zealand moa“Here we show that the Polynesian population of New Zealand would not have exceeded 2,000 individuals before extinction of moa populations in the habitable areas of the eastern South Island. During a brief (<150 years) period and at population densities that never exceeded ~0.01 km(-2), Polynesians exterminated viable populations of moa by hunting and removal of habitat. High human population densities are not required in models of megafaunal extinction."

A Gene by Any Other Name“What is the logic in naming human genes?”

bonus: Keeping Mates Close and Competition Out in an Ocean Sponge

bonus bonus: Here’s Why Other People’s Farts Smell Way Worse Than Your Own – we cover *all* aspects of human biodiversity here on the hbd chick blog! (~_^)

(note: comments do not require an email. an ocean sponge.)

there were a handful of science news stories out this past week about how a couple of researchers reportedly discovered a case of “group selection” in certain spiders (Anelosimus studiosus or tangle web spiders): for example, see Proving ‘group selection': Spider colonies need the correct mix of personalities to survive and Elusive Form of Evolution Seen in Spiders. a bunch of people on twitter got all excited about this finding, because they wonder if (some of them i think hope that) group selection might also apply to groups of humans. i agree: that would be very interesting to know one way or the other. so i went and read the original paper — Site-specific group selection drives locally adapted group compositions — to see what these guys had found.

before i offer up my admittedly layman’s thoughts on this paper, let me first say what a really neat piece of research this was! if there existed a nobel prize for geeky dedication and sheer nerdiness, these guys would’ve won it! — and i mean that as a compliment! the researchers, pruitt and goodnight, studied groups of tangle web spiders in the wild, captured some and brought them back to their lab, conducted personality tests on the spiders (yes! there are apparently personality tests for spiders!), painstakingly painted those little dots on the backs of individuals to keep track of them (you know, like how they sometimes do with bees), bred the spiders, released new groups of them back into the wild, and checked up on them one and two generations later to see how they fared. this is some really cool research! nerds ftw! (^_^)

but did they find evidence for group selection?

weeeellll, no, i don’t think so.

to begin with, right at the start of the paper pruitt and goodnight (p&g) define group selection as “selection caused by the differential extinction or proliferation of groups.” eeeehhhh, as far as i understand it, that’s not really the definition of group selection, and even the authors admit that their definition is a “broad” one.

group selection is more accurately defined as when “natural selection [operates] between groups of organisms, rather than between individuals.” in contrast, p&g’s broad definition could theoretically include cases in which natural selection worked between individuals (individual selection) which also just incidentally happened to result in the proliferation of the group to which the lucky selected individuals belonged. an example of this is the selection for lactase persistence in some humans in which those individuals who could drink milk as adults were able to leave behind more descendants than those individuals who could not. while lactase persistence might indeed have benefitted groups of milk-drinking individuals, natural selection did not act on the group, but rather on the individuals in that group. (pretty sure i stole this example from @supermisdreavus, but i can’t find where he said that right now.)

in other words, you always need to work out what the target of selection is: the group or the individuals that make up the group. (really it’s ultimately the genes, but — oh, nevermind.) remember that “‘a fleet herd of deer’ is really just a herd of fleet deer.”

so, really, the discussion could end right here, because i don’t think the authors are talking about group selection proper. but, since i’ve read the whole paper, i’ll carry on. (yes, i’m one of those people who’s never learned to quit while they’re ahead!)

a. studiosus spiders live either as solitary individuals or in groups where they cooperate on tasks like hunting and the raising of young. the individuals that live together in groups are, on average, more closely related to one another than those that live alone [pdf] — they’re generally as related to one another as though they were half-siblings. one reason why they’re probably not more related to one another in these groups — like to the degree that ants or bees in colonies often are — is that the males move between groups. remember that.

the personality types of the individual spiders in a. studiosus groups come in two sorts: docile and aggressive. the docile spiders are typically pretty laid back and aren’t much bothered by the presence of other spiders (even spiders from other species), whereas the aggressive individuals like their space — they’ll chase off other individuals. individuals of both types are found in groups of a. studiosus, but the frequencies vary. from the paper:

“At…high-resource sites, small colonies were dominated by docile females and the frequency of aggressive individuals increased with colony size. By contrast, at low-resources sites, small colonies were dominated by the aggressive phenotype and the frequency of the docile phenotype increased with colony size.”

well, that doesn’t sound too surprising at all. in locales where there is plenty of resources, there are more laid back individuals in the colonies, prolly ’cause being laid back works just fine. in areas where resources are lacking, more aggressive individuals do better. btw, they found that the heritability of these personality types in the spiders is 0.66.

groups that have more docile individuals (i.e. the ones in high-resource areas) are at a greater risk of invasion by other types of spiders which, over the long-term, tends to be a really bad thing for an a. studiosus colony (i.e. it’s usually destroyed). groups that have more aggressive individuals (i.e. the ones in low-resource areas) tend in bad times to experience too much “egg case cannibalism.” needless to say, that’s not a good thing over the long-term either.

what p&g did in their study was to introduce into the wild — into differing environments — groups having varying frequencies of these personality types [source]:

“He [pruitt] took spiders from warrior-heavy colonies and used them to assemble new groups that were heavy on the nannies. He also used spiders from mostly docile colonies to create warrior-laden groups. In addition, he assembled control groups that matched the composition of their original groups.”

what they found was that after three generations:

“60 percent of the colonies were extinct. Control groups that returned to their ancestral homes tended to do well, and those that were transplanted into a new environment generally died. Neither of these outcomes was much of a surprise.

The most interesting results came from colonies made up of spiders that had been forced into a composition different from the one they grew up in — warrior-majority colonies containing spiders from mostly docile groups, for example. The colonies whose composition fit the new environment tended to survive. But over time, surviving colonies reverted to their members’ original group composition. The warrior-majority colonies went back to having more nannies, for example. On the face of it, this is bizarre behavior; if the colonies are well-suited to their environment, why not maintain that ratio? It seems that some innate sense, perhaps encoded in the spiders’ genes, pulled the colony back to its original configuration, even though this change meant the colony would perish.”

well, i dunno. is that really “bizarre behavior?” i mean, if the personality types of a. studiosus are really highly heritable (0.66), is it strange that a population having come from a bunch of docile individuals should regress toward a docile mean? and vice versa? don’t forget, too, that the individuals in these groups are all related to one another as though they were half-siblings, so presumably individuals of either personality type might carry a great many genes of the other type in their genomes. (don’t know about that — i’m just guessing here, tbh.)

what really made me question whether or not this is “bizarre behavior” is the way in which the researchers bred the spiders when they had them in captivity [from the methods section at the end of the paper]:

“Females were mated randomly to a male of like behaviour type from their same source population, but which was collected from a source colony >5m distance.”

hmmmm. i dunno about that. they mated all the females with males of the same personality types, docile or aggressive? i’m guessing that they did this in order to reduce the number of possible confounding factors in the study, but i’m afraid they might’ve added something to the mix here that wouldn’t be found in nature, i.e. a 100% assortative mating rate (for personality type). mightn’t this almost guarantee that individual spider lineages would regress to their original personality-type means? docile females always mated with docile males and aggressive females always mated with aggressive males? that seems unlikely to happen in nature, especially given the fact that the males normally leave their colonies and move to others. (btw, male a. studiosus spiders prefer moving into colonies over mating with lone females. typical males, favoring harems! (~_^) )

p&g offer a number of explanations for how the frequencies of personalities in the groups might change over time:

“How native spiders are actually able to adjust their composition is unknown, but plausible regulatory mechanisms include developmental plasticity in the docile:aggressive phenotypes, policing of group membership, phenotype-biased dispersal, and/or selective cessation of reproduction.”

they reject the first explanation (the plasticity one) on the basis (in part) of the rather high heritability of spider personality types which they found. i’m inclined to agree with them on that.

out of their other reasons, policing of group membership and selective cessation of reproduction are behaviors that can be easily explained by natural selection between individuals, especially in populations that have rather highly related individuals so that levels of altruism are pretty high. the selective cessation of reproduction occurs, for instance, in some ant colonies since, due to the really high degrees of relatedness between individuals, the inclusive fitness payoffs are really large (eg. if you share three-quarters of your dna with your sister’s offspring, there’ll be a greater genetic payoff in helping her to reproduce rather than reproducing yourself, since you’d only share half of your genome with your offspring). that’s individual selection, not group selection. h*ck! both behaviors also occur in meerkat groups, although they, of course, show much less specialization of individuals than ants or bees. the policing of group membership can also be plausibly explained by natural selection between individuals — for example, aggressive individuals keep at bay all sorts individuals because that’s good for aggressive individuals (who are typically found in sparse environments).

so, i’m not at all convinced that pruitt and goodnight have found an example of group selection. i think they’ve found that genetics (as indicated by the heritability of the spiders’ personality traits) and natural selection certainly shape the average characteristics of groups, but it looks to me as though the seemingly “bizarre behaviors” that they found can easily be explained by individual selection. in fact, i’m more than a little concerned that due to the way they bred the spiders, p&g may have affected the outcomes of the reintroduced groups.

see also: The False Allure of Group Selection from steven pinker.

(note: comments do not require an email. a. studiosus group web!)

we know that human biodiversity (hbd) is true because, for one thing, we have many, many examples of it (see here)!

additionally, both the workings of the natural world and specifically the theory of evolution predict that hbd must be the case.

nature likes to throw up variety (see here for example) — the variation between individual organisms is, after all, what natural selection acts upon — and there’s no reason for humans to be any exception. add to that the fact that humans reproduce sexually — with all the genetic shuffling and remixing that happens there — and it’s inevitable that individual humans will be biologically diverse.

various groups or populations of humans — ranging from small-sized families to races and even beyond (for example, think: east asians+native americans together compared to caucasians or subsaharan africans) — will also inevitably be biologically diverse from one another, to greater or lesser degrees, due to forces of evolution such as natural selection, gene flow, and/or genetic drift.

keep in mind that humans — including various discrete-ish human populations (biological borders are fuzzy, naturally) — have experienced recent evolution (i.e. within the last 40,000 years or so), that human evolution has probably sped up since the advent of agriculture, and that we are undoubtedly still evolving today.

ignoring or denying the existence of human biodiversity won’t make it go away. hbd — and its implications — will remain a reality in spite of all your hopes and dreams, however well-intentioned they may be.
_____

this is one of a set of posts on What is Human Biodiversity? please, before you fire off a rant leave a comment here, check out the other posts, because your question or objection may have been dealt with in one of them. here they all are!:

what is human biodiversity (hbd)?
what human biodiversity (hbd) is not
examples of human biodiversity (hbd)
hbd and racism
hbd and politics

(note: comments do not require an email. another great moment in evolution.)

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