|« Not A Girl, Yet Not A Woman | Gene Expression Front Page | Hell No, We Won't Go! We're Having Kids! »|
January 12, 2003
The Carnival of Race
A month ago a study came out that showed that most white Brazilians had a large number of non-white ancestors (over half their female progenitors in fact). This was shown as proof by some that race is a social illusion. But many ignored this quote:
And almost simultaneously, results were produced by other scientists that indicated that there were five geographical groups of human beings-races.
How do we resolve this? The short answer-it's complicated, and obvious answers are not always correct.
Brazilians are obviously a racial mix-and this mixing has been happening for 300 years. It seems that certain genes associated with selected phenotypes have been assorted over the generations to various segments of the populace to produce the illusion of relative whiteness, despite the underlying genome still attesting to a large quotient of non-white ancestry.
Say what? OK, assume you have two individuals, half-Swedish and half-Nigerian, who marry and have children. Let us say that the grandparents who were Swedes were blue-eyed, and the Nigerians brown-eyed. In the most simple explication of mendelian inheritance, the two individuals of mixed-race would have brown eyes but still carry a blue eyed gene. 1/4 (statistically) of their children would be homozygous for blue eyes, and so would display that phenotype. In fact it seems not implausible that if these two individuals had 10 children some of these ten would look more "white" and others would be more "black" in appearance, while the balance would be somewhere in between.
The ones who looked more "white" expressed more of their Swedish grandparent's genes for easily identifiable phenotypes (for instance, blue eyes, or possibly blonde hair). The opposite would be true for those who looked more black. In Brazilian society people who could "pass" as white but were genetically considerably non-white still might have mostly European genes for phenotypes that are traditionally markers of what it means to be white-light hair, eyes or wavy rather than kinky hair, etc. The light hair and eyes are recessive, as I believe is non-kinky hair (this is up for debate, lots of these traits are polymorphic, with multiple genes contributing to a phenotype), so would "breed true" and their children with other "white looking" people would also be white despite their considerable non-white ancestry (still evident in the Y chromosome and mt-DNA as well as many other genes that are coding for processes not noticed with the eye but might be different between races-for instance, the difference in processing carbohydrates that leads to obesity in black women).
Brazil-where race mixture has been much more common historically than in most parts of the world, is a particular case. For most Europeans in Sweden, their phenotype is a good signature of their overall genome, while most Nigerians are Nigerian, explaining why though there are specific exceptions to mapping phenotype to overall genotype (Brazil, individuals of mixed race), it is still generally a good rule of thumb.
But the key is that it is a rule of thumb. This is why I reject the almost religious appeals to racial solidarity made by race activists, whether white, black, brown or yellow. If someone has many non-white ancestors, but are physically white, are they part of the "racial soul"? But what if someone has white ancestors, but by some chance of nature is more racially ambiguous in appearence:
My final point would be this: many Brazilian whites carry genes that might code for phenotypes that we don't think of when we think "race." I believe elements of behavior are strongly influenced by genotype, and if these factors were not assorted by Brazilian social norms ("good hair" = not kinky, "good features" = European, etc. are easy to see, r vs. K selection a la Rushton's rule is not), than Brazilian whites might not act how we believe whites would act based on adaptation to Ice Age conditions in Europe, but more like their African or Amerindian forbears.
Update: Juan points me to this article debunking the Brazilian study's claims. Not totally convinced-the Brazilian study still surprised me even though I do agree the authors overplayed their hand. But, it makes the same point that I just did above, that it is particular to Brazil and shouldn't be generalized.