Misc. links

Genetic Genealogy Comes of Age: Perspectives on the Use of Deep-Rooted Pedigrees in Human Population Genetics

Facial Structure Is Indicative of Explicit Support for Prejudicial Beliefs

Our results indicate that males with a greater fWHR are more likely to explicitly endorse racially prejudicial beliefs, though fWHR was unrelated to implicit bias. NN

"Ironically" (according to Vice blogger) a Man's Face Can Tell You If He's Likely to Act Racist

There’s an obvious irony to a study that says we can tell if a man will act bigoted based on the shape of his face. But the logic underpinning the study, conducted by researchers at the University of Delaware and soon to be published in the journal Psychological Science, is a circuitous and unexpected one, and makes a persuasive case.

Turns out it’s all about the testosterone.

Recent research indicates that men with high levels of testosterone have certain facial characteristics that set them apart from men with less testosterone. In particular, they have what researchers call a higher facial Width-to-Height Ratio (fWHR) which compares the distance between cheekbones to the distance between the upper lip and midbrow.

Charlton: Modern sub-fertility may be a pathologically slow life history, triggered by a supernormal stimulus of modernity

The Human Varieties Global IQ Dataset / HVGIQ

Human Varieties: Colorism in America?

Light skin color does not seem to cause higher IQ or educational achievement either through pleiotropy or because of color discrimination — otherwise the within-families correlations would have been similar to those obtained between families. Colorism, the theory that discrimination based on skin color is a major source of socioeconomic differences, appears to not apply within the African American population, at least as far as IQ and educational attainment are concerned.
Genetic Influences on the Overlap Between Low IQ and Antisocial Behavior in Young Children
The well-documented relation between the phenotypes of low IQ and childhood antisocial behavior could be explained by either common genetic influences or environmental influences. These competing explanations were examined through use of the Environmental Risk Longitudinal Twin Study 1994–1995 cohort (Moffitt & the E-Risk Study Team, 2002) of 1,116 twin pairs and their families. Children’s IQ was assessed via individual testing at age 5 years. Mothers and teachers reported on children’s antisocial behavior at ages 5 and 7 years. Low IQ was related to antisocial behavior at age 5 years and predicted relatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This association was significantly stronger among boys than among girls. Genetic influences common to both phenotypes explained 100% of the low IQ–antisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes.
Toxoplasma gondii infection enhances testicular steroidogenesis in rats (pdf)

The genetic origin and history of speed in the Thoroughbred racehorse and a related talk

Selective breeding for speed in the racehorse has resulted in an unusually high frequency of the C-variant (g.66493737C/T) at the myostatin gene (MSTN) in cohorts of the Thoroughbred horse population that are best suited to sprint racing. Here we show using a combination of molecular- and pedigree-based approaches in 593 horses from 22 Eurasian and North-American horse populations, museum specimens from 12 historically important Thoroughbred stallions (b.1764-1930), 330 elite-performing modern Thoroughbreds and 42 samples from three other equid species that the T-allele was ancestral and there was a single introduction of the C-allele at the foundation stages of the Thoroughbred from a British-native mare. Furthermore, we show that although the C-allele was rare among the celebrated racehorses of the 18th and 19th centuries, it has proliferated recently in the population via the stallion Nearctic (b.1954), the sire of the most influential stallion of modern time, Northern Dancer (b.1961).
Alistair Overeem's testosterone level at dangerously low levels in Antonio Silva fight
Overeem's test, taken the morning after the fight, was low enough that most doctors would recommend him to be on a testosterone replacement plan even if he was not an athlete [. . .]

Overeem went from being a 205-pound light heavyweight who lost frequently, to looking like a different human being, gaining nearly 60 pounds of competitive weight with no increase in body fat. Due to that, he probably had more suspicion over steroids than nearly any MMA competitor, even before he tested positive the first time he was tested on a date he wasn't told about well in advance.

Save the Pygmies

Pygmy slavery is a wide range from being held to gunpoint by rebel militia's in the gold, diamond, and coltan mines to being slaves because of no possibility of monetary gain or obtaining land ownership. The Pygmies that we have been seeing released are not being held to gunpoint or in shackles. The kind of slavery we are immediately putting an end to is slavery due to having no other option to survive. The easiest way to end this kind of slavery has been to see them be placed on their own land, and then showing them how to work it for themselves instead of their slavemasters. This year in Congo will give more insight into all the unique kinds of slavery and what action can be taken for the Pygmies of Africa (Meaning a future goal to expand into other countries where the Pygmy people reside). The main reason for Pygmy slavery is due to extreme racism where surrounding tribes believe the Pygmy people are still in the transitional stage from monkey to human. This belief accounts for the hunting, killing, cooking, and cannibalism against the tribe as well as other atrocities against humanity in recent years.
Gene flow and the limits to natural selection
In general, individuals who survive to reproduce have genotypes that work relatively well under local conditions. Migrating or dispersing offspring elsewhere is likely to decrease an individual's or its offspring's fitness, not to mention the intrinsic costs and risks of dispersal. Gene flow into a population can counteract gene frequency changes because of selection, imposing a limit on local adaptation. In addition, the migrant flow tends to be higher from densely populated to sparsely populated areas. Thus, although the potential for adaptation might be greatest in poor and sparsely populated environments, gene flow will counteract selection more strongly in such populations. Recent papers, both theoretical and empirical, have clarified the important role of migration in evolution, affecting spatial patterns, species ranges and adaptation to the environment; in particular, by emphasizing the crucial interaction between evolutionary and demographic processes.

local adaptation; gene swamping; migration rescue; migration meltdown; gene flow; natural selection


FredR said...

What do you think of Charlton's idea? I've always had a soft-spot for that life-history stuff, ever since I read Janes Chisholm's "Death, Hope, and Sex", but I've never been able to convince myself that it probably isn't really just genetics, rather than responses to environmental stimuli. And of course, Charlton takes it a step beyond that. But it's a neat little theory.

Anonymous said...

Is Charlton worth reading in general? I've skimmed his stuff before and he seems to have a lot of dumb views. I've also heard that he censors comments that correct mistaken statements he makes or that dispute his views.

n/a said...


I don't really buy Charlton's idea as an actual explanation, but I found the post at least momentarily interesting.

The failure to reproduce can perhaps be conceptualized as an extreme, pathological lack of urgency concerning reproduction [. . .] ...Rather as if each child implicitly responded to the ultra-secure, supernormal stimuli of modern childhood with a built-in but subliminal expectation that she will live for 200 years with more than a century of youthful fecundity and vigour - and delays reproductive effort accordingly.

I've seen analyses like this that seem inconsistent with that explanation: "Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development-fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries."

For me, Charlton's post is more useful as a reminder to those who read it that indeed we are not going to live 200 years.

"never been able to convince myself that it probably isn't really just genetics, rather than responses to environmental stimuli"

Obviously, it's both. People with identical genes in 1640 New England and 1940 New England realized very different levels of fertility.

Off the top of my head, I don't know what proportion of inter-individual differences in fertility under modern conditions are explained by genetic factors, but I certainly expect they're there and that given enough time (without being swamped by immigrants) sub-replacement fertility in Western countries would tend to naturally reverse itself. A downside of leaving it to nature (besides the fact that in the presence of extreme levels of non-European immigration Western countries don't have the luxury) is that selection of high fertility under modern conditions might end up also selecting for, e.g., lower IQ.

With something like embryo selection (PIGD), on the other hand, it will almost certainly become possible (given that the necessary relatively straightforward behavioral genetic research occurs) to select on, for example, a combination of IQ and expected fertility under modern conditions.

But I expect most babies will be made the traditional way for a long time to come.

So this leaves environment/culture as something that clearly needs to change.


Not saying I read all his posts, but I do find Charlton interesting.