Posted by: Dan | February 8, 2009

More Thoughts on Race and Humanity

More links relating to my recent interest in the notion of biological races of our species. I highly recommend following Dienekes’ and John Hawks’ Anthropology blogs for people interested in this topic.

Especially these two posts: Debunking the concept of ‘race’ … not and If you are going to “debunk” race with gene testing, please stop, with especially the latter providing a partial explanation of the fuzziness of race (the idea of “pure” races is nonsense).

Humans do not have discrete races. Racial groups in humans do not have reproductive boundaries. Genetic variation in humans is clinal. Allele frequencies of most human genes do not vary by much between populations.

At the same time though, we have to remember Lewontin’s Fallacy — Depending on how you manipulate the genetic data, discrete races can be resolved or not:

Lewontin’s Fallacy is a 2003 paper by A.W.F. Edwards that criticizes Richard Lewontin’s 1972 conclusion that race is an invalid taxonomic construct, because the perception that most differences occur between groups rather than within groups is incorrect. Because the overwhelming majority of human genetic variation (85%) is between individuals within the same population, and that about 6–10% is between populations within the same continent, he concludes that racial classification can only account for between 5–10% of human variation, and is therefore of virtually no genetic or taxonomic significance. This implies that any two humans from the same group are almost as different as any two humans from different groups.

Edwards argued that while Lewontin’s statements on variability are correct when examining the frequency of individual loci between individuals, the probability of misclassification rapidly approaches 0% when one takes into account more loci. This happens because differences at different loci are correlated across populations — the alleles that are more frequent in a population at one locus and those that are more frequent in that population at another locus are correlated when we consider the two populations simultaneously. In Edwards’ words, “most of the information that distinguishes populations is hidden in the correlation structure of the data.” These correlations can be extracted using commonly-used ordination and cluster analysis techniques. As Edwards showed, even if the probability of misclassifying an individual based on a single locus is as high as 30% (as Lewontin reported in 1972), the misclassification probability based on 10 loci can drop to just a few percent.

How many loci is it reasonable to use to fairly reflect human diversity though? We know that the idea of “pure” races is nonsense, and we’re not trying to deny that there has been substantial gene flow producing rough clinal gradations of human variation.

Put another way, my working definition of race involving “partial inbreeding” as a criteria appears to be a slippery slope. At just what threshold does “partial inbreeding” become insignificant, and a proposed racial boundary disappear? Depending on your answer, you may agree that there are three major biological human races, that they can be subdivided further, or that there are none at all. Is it just arbitrary?

And moreover, an overarching ethical question: knowing the propensity of people to misuse findings (correct or fabricated) on human races, is it racist to try and even ask the question “are races real”?

Update: Thanks to the automatically generated “possibly related posts” module offered by WordPress, I came across yet another helpful essay on race, etc.: neuroanthropology and race- getting it straight. Check out the comments too.

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Responses

  1. One other thing about this topic. It seems that the field is divided as how to discuss it. That said, as a postdoc you should be aware of how strong one can be when defending their opinion. GL spent a great deal of time in his field and has formulated an opinion. Whether right or wrong he’s not going to abandon the position without overwhelming evidence.
    It’s very much the Kuhn paradigm, where one once a prevailing belief is established, investigation to the contrary is met with strong opposition. The “harm” argument, regardless of your opinion of it, has an equally strong emotional attachment, doubling the affect.
    I am of the opinion that words are not an end all be all. How many people remember that fantastic has its roots in fantasy, that incredible means not unbelievable, and terrific and terrible are just about synonymous? Even pejoratives such as “dyke” have been co-opted by the people it was intended to disparage. IMO, this hand-wringing over the term simply provides fuel to those who would misuse it.

  2. Onkelbob,
    Well sure, science is normative, “experts” don’t communicate well at all with relative latecomers to their field of study, and science is often counter-intuitive when examined in depth. It’s a perennial problem – but what’s one to do but keep trying…


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