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In response to my post Mixed-race but homogeneous appearance? several individuals mooted the possibility that admixture may result in the vanishing of race as a social construct. Actually, I don’t think this is the true. To the left is a photo from my post Can you tell if you’re black or white? where I explored the genetics of a case where two black-white biracial parents produced fraternal twin daughters of disparate appearance. While one sister seemed to favor her African ancestors in look, another sister seemed to resemble her European forebears. Across the full sample space of their genome it seems likely that both these girls are about half European and half African in ancestry, but on the finite loci which are salient in the production of the features which we use to code for “races” they most certainly favor one ancestral group over the other. The basic point is that a population, and individuals, can exhibit great admixture and yet still realize the full phenotypic range of the ancestral types. This is because genetics is not blending, admixture will not result in a homogenization toward a mean unbounded by a distribution characterized by variance.

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So says the European Journal of Human Genetics, in response to the flood of data from genome-wide association studies and other genomic data in the field of human genetics:

[O]ne might maliciously wonder if we are not (temporarily, in this field and pending subsequent functional studies) close to the ultimate consumption date of the Popperian approach of hypothesis-driven research. For was not a main goal of this to unravel the truth in the most efficient, that is, plausible way, faced with a daunting scarcity of collectible data? Well, if it becomes cheaper to just collect all data required than to run after a hundred consecutive, plausible, but wrong hypotheses, starting with a hypothesis becomes an economic futility. The hypothesis as a guiding principle is then replaced by a truism: if one does not throw away anything before thoroughly assessing its irrelevance, one will always find what one is looking for.

Ross Douthat introduces The Table: Atlantic Voices in Conversation. I dig the head bob! Very professional.

Ed, Greg & PZ have commented on the strange reaction of the president of the Southern Baptist Theological Seminary toward Richard Dawkins’ enthusiasm for Christmas traditions. So “why would an atheist want to sing Christmas carols?”
The same reason that the study and reading of literature has not been reduced to physics. We humans appreciate great stories, and we can conceive in our mind’s eye ideas which may not be true, but we enjoy the play of those ideas nonetheless. One does not have to be a Greek pagan to appreciate the beauty and power of the Iliad, and in fact for centuries pious Christians have been moved by the poems of Homer without acceding to the reality of its relgious vision. For them Homer was not about the Truth of the gods, but the Truth of human experience. We don’t need to appeal to a classical education though, anyone who reads a piece of moving fiction can be emotionally impacted, without entertaining that the narrative is real in a positivistic sense.

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EVOLUTIONARY ADAPTATIONS: THE IMPACT OF LIGHTER SKIN:

It would take someone with dark skin of African or South Asian ancestry about 60 minutes at the same time of day to make the amount of vitamin D that a person of European ancestry would make in about 10 minutes, estimates Reinhold Vieth, one of Canada’s top vitamin D experts and a professor in the department of nutritional sciences at the University of Toronto.

You probably know of Vitamin D deficiency for rickets, but I think more common ailments might have a major fitness impact:

VDR ligands have also been shown to increase the activity of natural killer cells, and enhance the phagocytic activity of macrophages…Active vitamin D hormone also increases the production of cathelicidin, an antimicrobial peptide that is produced in macrophages triggered by bacteria, viruses, and fungi…Vitamin D deficiency tends to increase the risk of infections, such as influenza and tuberculosis. In a 1997 study, Ethiopian children with rickets were 13 times more likely to get pneumonia than children without rickets

More ‘altruistic’ punishment in larger societies:

…Second-party punishment is when you punish someone who defected on you; third-party punishment is when you punish someone who defected on someone else. Third-party punishment is an effective way to enforce the norms of strong reciprocity and promote cooperation. Here we present new results that expand on a previous report from a large cross-cultural project. This project has already shown that there is considerable cross-cultural variation in punishment and cooperation. Here we test the hypothesis that population size (and complexity) predicts the level of third-party punishment. Our results show that people in larger, more complex societies engage in significantly more third-party punishment than people in small-scale societies.

So The Superficial is reporting that Jamie Lynn Spears is pregnant by her boyfriend Casey Aldridge. Jamie Lynn is Britney Spears’ younger sister, and at 16 she will be a “teen mother,” but not a stereotypical one. Jamie Lynn Spears has her own television show and seems to have her shit “together.” The stereotype is that the poor and those of lower SES are more likely to get pregnant as teens. That is statistically true:

Compared to teens from higher income families, poor and low-income teens are somewhat more likely to be sexually active and somewhat less likely to use contraceptives or to use contraception successfully. Poor and low-income adolescents make up 38 percent of all women ages 15 to 19; yet, they account for 73 percent of all pregnancies in that age group.
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Nearly 60 percent of teens who become mothers are living in poverty at the time of the birth.

I recall reading a Naomi Wolf book years ago where she recounted that though her family income was lower-middle-class, sociologically her outlook was middle to upper-middle-class (i.e., the perpetual graduate school set). I think what you have with the Spears is the inversion, though wealthy because of their success in the entertainment industry they exhibit the ticks of those in lower social classes. I don’t need to repeat Britney Spears’ “adventures” of late. Here’s some possible highlights from the Spears family history:

Us has learned that Spears’ paternal grandmother, Emma Jean Spears, in June 1966 committed suicide at age 31. Britney’s grandmother, who suffered from depression, shot herself in the chest with a shotgun at the grave of her infant son who had died eight years earlier just three days after being born.
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Emma Jean Spears left behind four other children, including Britney’s father, Jamie Spears, then an eighth grader. Two of Jamie Spears’ brothers ended up with criminal records and homeless.

The Spears’ wealth did not come via the typical bourgeois path of investment in education and skills which result in a low risk high yield career path. So it is no surprise that once Britney got free of her “handlers” she has behaved in a way that many middle class Americans find abhorrent. And anyone who has read Judith Rich Harris’ book The Nurture Assumption also knows one should be cautious of assuming that this sort of behavior and life outcomes are due simply to socialization or environmental inputs. Rather, a good proportion of personality and the sum of characteristics which shape the probability distribution of choices given a conventional range of options is contingent upon genetic variation.

Check out Four Stone Hearth #30.

Family Ties That Bind: Maternal Grandparents Are More Involved In The Lives Of Their Grandchildren:

For grandparents living within 19.5 miles (30 km) of their grandchildren, over 30% of the maternal grandmothers had contact daily or a few times a week. Around 25% of the maternal grandfathers had contact daily or a few times a week. In contrast, only around 15 % of the paternal grandmothers and little more than 15% of the paternal grandfathers would have contact daily or a few times a week.

The sample was Dutch, and the authors hypothesize that the reason that maternal, as opposed to paternal, grandparents go the extra mile is that they are wholly certain of their genetic relationship. In other words, motherhood is certain and fatherhood is theoretical (though this varies by society). This isn’t a new finding, and the results can be found in societies. It also manifests in the Grandmother Effect studies, maternal grandmothers quite often invest more than paternal grandmothers in their grandchildren.

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