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Race Cannot be Wished Away

The New York Times has recently been quite bold in upholding the common sense view that race is not a mere sociological artifact but a biological reality. In a recent article, Nicholas Wade writes:

“A view widespread among many social scientists, endorsed in official statements by the American Sociological Association and the American Anthropological Association, is that race is not a valid biological concept. But biologists, particularly the population geneticists who study genetic variation, have found that there is a structure in the human population. The structure is a family tree showing separate branches for Africans, Caucasians (Europe, the Middle East and the Indian subcontinent), East Asians, Pacific Islanders and American Indians.

“Biologists, too, have often been reluctant to use the term ‘race.’ But this taboo was broken last year by Dr. Neil Risch, a leading population geneticist at Stanford University.

“Vexed by an editorial in The New England Journal [of Medicine (NEJM)] that declared that race was ‘biologically meaningless,’ Dr. Risch argued in the electronic journal Genome Biology that self-identified race was useful in understanding ethnic differences in disease and in the response to drugs.”

The news peg for Mr. Wade’s article was the appearance in the NEJM of two articles that reopen the debate on race two years after a staff-written editorial dismissed its scientific validity. The debate is accompanied by a new editorial taking the view that it is “unwise to abandon the practice of recording race when we have barely begun to understand the architecture of the human genome.”

Mr. Wade goes on to point out that although the same genes are usually implicated in the same diseases worldwide, there are still important racial differences: “Inheriting two APOE4 genes, one from each parent, raises the risk of Alzheimer’s 33 times in Japanese populations, 15 times in Caucasians and only 6 times in Africans. This suggests that some unknown factor modifies the effect of the APOE4 gene in different races. . . .” [Nicholas Wade, 2 Scholarly Articles Diverge on Role of Race in Medicine, New York Times, March 20, 2003.]

The notion that race is not based in biology has made significant inroads in popular thinking but appears to be in serious retreat among specialists.

His Keeper’s Brother

A new study by biologists at Wayne State University in Detroit has concluded that humans and chimpanzees are so closely related genetically that chimps should be included in the Homo genus, along with humans. A genus is the first-level grouping of closely-related species. The genus Canis, for example, includes dogs, foxes, wolves, coyotes, jackals, etc., and Equidae includes nine species of horses, donkeys and zebras. We are currently the only member of genus Homo, although we have a number of extinct relatives such as Homo erectus and Homo neanderthalensis. Long lost cousin clinging to our branch of the evolutionary tree?

The authors of the Wayne State Study, which has just appeared in Proceedings of the National Academy of Sciences, argue that although traditional zoologists decided chimps were more closely related to gorillas than to humans, DNA studies show otherwise: We are the chimps’ closest relative, having diverged from a common ancestor five or six million years ago. The authors point out that many species that diverged longer ago than that are included in the same genus, and they say it makes no biological sense to give humans special treatment with a genus all their own. DNA analysis gives varying figures for the extent of genetic similarity between chimps and humans depending on which part of the genome is studied, but the authors have found that for long stretches of important, functional DNA there is 99.4 percent similarity. They propose that chimpanzees, now called Pan troglodytes, be renamed Homo troglodytes and be welcomed into the family. [John Pickrell, Chimps Belong on Human Branch of Family Tree, Study Says, National Geographic News, May 20, 2003.]

If there is so little genetic difference between us and chimps we belong in the same family, it is clear that very small genetic differences can produce very significant physical differences.