Mixed Race Studies

How Genetics Is Changing Our Understanding of ‘Race’

Sunday Review
Gray Matter
The New York Times
2018-03-23

David Reich, Professor of Genetics
Harvard Medical School
also, Investigator, Howard Hughes Medical Institute

Angie Wang

In 1942, the anthropologist Ashley Montagu published “Man’s Most Dangerous Myth: The Fallacy of Race,” an influential book that argued that race is a social concept with no genetic basis. A classic example often cited is the inconsistent definition of “black.” In the United States, historically, a person is “black” if he has any sub-Saharan African ancestry; in Brazil, a person is not “black” if he is known to have any European ancestry. If “black” refers to different people in different contexts, how can there be any genetic basis to it?

Beginning in 1972, genetic findings began to be incorporated into this argument. That year, the geneticist Richard Lewontin published an important study of variation in protein types in blood. He grouped the human populations he analyzed into seven “races” — West Eurasians, Africans, East Asians, South Asians, Native Americans, Oceanians and Australians — and found that around 85 percent of variation in the protein types could be accounted for by variation within populations and “races,” and only 15 percent by variation across them. To the extent that there was variation among humans, he concluded, most of it was because of “differences between individuals.”

In this way, a consensus was established that among human populations there are no differences large enough to support the concept of “biological race.” Instead, it was argued, race is a “social construct,” a way of categorizing people that changes over time and across countries.

It is true that race is a social construct. It is also true, as Dr. Lewontin wrote, that human populations “are remarkably similar to each other” from a genetic point of view…

Read the entire article here.

Racial Medicine: Not So Fast

The Daily Beast
2008-08-19

Sharon Begley, Senior Health and Science Correspondent
Reuters

Next time you want to start a bar fight, proclaim to everyone within earshot that “race is not real; it is just a social and cultural construct and has no biological validity.” Then duck before you get punched in the face. . . . but as you’re avoiding injury try to hand your would-be assailants a new paper published online this afternoon by the journal Clinical Pharmacology & Therapeutics, which concludes that classifying people by the crude category of race—as in, of African, Asian or European ancestry—for medical purposes, as some people want to do, is really, really stupid…

…Which brings us to the new study. Scientists at the J. Craig Venter Institute got the cool idea of analyzing the genomes of two white guys who, according to the conventional racial categories, belong to the same race. The two are Venter himself and James Watson, co-discoverer of the double-helix structure of DNA. Venter led the private effort to sequence the human genome, winding up in a tie with the public project to do the same.

It happens that the genomes of both men are in the public domain. Watson agreed to have his sequenced and published last year, with Venter right behind. So what do the genomes reveal?

The two men metabolize drugs, including antidepressants, codeine, antipsychotics and the cancer drug tamoxifen, differently. Venter has two functional copies of the CYP2D6 form of the cytochrome P-450 gene, which metabolizes more than 75 percent of drugs, while Watson has two copies of the more-sluggish variant of the gene. That’s rare for Caucasians (only 3 percent of whites have the sluggish version), but common in East Asians (49 percent of whom have it). Funny, Watson doesn’t look Chinese. But if Watson’s doctor decided to use race-based medicine to predict how he would metabolize drugs, she’d say, well, we have a white guy here, and whites rarely have the sluggish version, so I’ll assume Watson doesn’t have it either. As a result, the drug would stay in Watson’s system longer, with stronger effects compared to someone in whom the drug was quickly metabolized and cleared from the body. “It is unlikely that a doctor would guess that optimal drug dosages might differ for Drs. Watson and Venter,” the scientists write.

That’s why Venter and colleagues conclude that race is too crude a proxy for what genetic group—ethnicity or, as biologists say, population—someone belongs to. It is imperative to “go beyond simplistic ethnic categorization,” they write, since that can be seriously—and perhaps fatally—misleading. (In the U.S., some 100,000 people a year die of adverse drug reactions, many caused by an inability to properly metabolize the medication because of a particular CYP2D6 variation.) “Race/ethnicity should be considered only a makeshift solution for personalized genomics because it is too approximate,” they write…

Read the entire article here.