Evolutionary biologist: race in humans a social, not biological, concept

May 20, 2003 -- The notion of race in humans is completely a social concept without any biological basis, according to a biologist at Washington University in St. Louis.

In the 50th year since the discovery of DNA, Washington University evolutionary and population biologist Alan Templeton says that there are not enough genetic differences between groups of people to say that there are sub-lineages (races) of humans.

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There are not enough genetic differences between groups of people to say that there are sub-lineages (races) of humans, said Alan R. Templeton, Ph.D., professor of biology in Arts & Sciences at Washington University in St. Louis. On the other hand, there are different races in many other species, including chimpanzees, our closest evolutionary relatives.

Templeton is a renowned evolutionary and population biologist who has analyzed billions of genetic pairings called base pairs for numerous evolution and population biology studies. He has shown that while there is plenty of genetic variation in humans, most of the variation is individual variation within local populations. While between-population variation exists, it is quantitatively small and does not mark historical sublineages of humanity.

"I'm not saying there aren't genetic differences among human populations," he cautioned. "There are differences, but they don't define historical lineages that have persisted for a long time, which is one criterion for race in a scientific sense."

Templeton was part of a St. Louis panel discussion that previewed the first episode of the National Public Television's "Race: The Power of an Allusion" series running nationally on May 4, 11 and 18 (check local stations for times). The first episode is "How different are we really?" The second one is "Where did the idea of race come from?" The third is "Just because race isn't biological doesn't mean it isn't real."

Last spring in an article published in Nature magazine, Templeton analyzed many different gene trees based on human DNA sequence data and showed that humans long had genetic interconnections all over the globe. He showed that there were at least two major waves of human migration out of Africa. DNA evidence suggests also that these wanderers bred with the people they encountered, rather than replaced them, in a "make-love-not-war" scenario.

"There is more and more hard genetic evidence that all of humanity has evolved as a single unit, with regional variations, but that's all they are, slight variations," said Templeton. "A race has to be a sharply defined, geographically circumscribed population that represents an isolated or nearly isolated lineage within the species. There's nothing at all like that in humanity. In terms of the living world, it's really hard to find a species so genetically homogeneous across its populations as humans."

Templeton said that the genetic variation between different geographical populations in humans — what some might incorrectly consider to be "race" — does make a difference when it comes to transplanting organs because organs have to be genetically compatible. The best predictor of overall genetic differences is how far apart geographically the ancestral populations are.

"We need to look at these indicators of genetic differentiation directly and not just tied into skin color or race because that's not actually the most reliable indicator of the differences," said Templeton. "For instance, let's say you have a person from Micronesia who needs a transplant. These are people who have dark skin and resemble western Africans. Yet genetically the Micronesian is closer to a European than he is to an African. So, the skin color here is not a reliable indicator. It's actually more important to find out a geographical ancestry than a donor's skin color. For instance, Tiger Woods is mostly Asian in his ancestry. If he should need a transplant some day, he will be more likely to match an Asian donor.

"It's geography and not culture or skin color that matters in this instance."