Genetics research increasingly finds "race" a null concept

Similarities in humans outweigh all differences

April 04, 1999|By Scott Shane | Scott Shane,SUN STAFF

A growing scientific consensus is rejecting the racial categories that still dominate American life as biologically almost meaningless, a vestige of 18th-century pseudoscience that has only confused humans' struggle to understand themselves.

The impact of the scientific critique of race is only now beginning to be felt outside scholarly meetings and genetics labs.

It fueled a heated debate over the racial terms in the 2000 U.S. Census and prompted a plea from the American Anthropological Association to drop race altogether from the 2010 Census. It has provoked a rethinking of racial interpretations of human differences in fields from medicine to athletics.

But the popular belief that humans are divided by nature into biological races is deeply rooted in history and culture. Like the early astronomers and explorers who eventually vanquished the illusion that the sun revolved around a flat Earth, anthropologists and geneticists are wielding scientific data against what people think they see with their own eyes.

The grab bag of superficial physical differences people use to define race, the scientists say, are minor variations that have obscured humans' overwhelming genetic similarity and common ancestry in Africa 100,000 to 200,000 years ago. The deeper researchers are able to peer into the human blueprint of DNA, the more irrele- vant race appears to be in defining human differences.

"Genetics has really exploded the concept of race," says the pioneering geneticist Victor A. McCusick of Johns Hopkins University.

The notion that races are biologically distinct groups with peculiar talents and weaknesses is an illusion, the scientists say.

There is only a spectrum of skin colors, hair textures, facial types and body shapes, loosely related to ancestral location on Earth.

"Race is an artificial construct that cannot be defended by any existing biological data," says Kenneth K. Kidd, a Yale University geneticist.

"There's no place in the world where you can draw a line and say the people on one side have a qualitative difference biologically from the people on the other."

Drawing lines between races, however dressed in pseudoscience, has always been a cultural and political act.

Arbitrary distinctions

The divisions -- whether three races or five or 15, all common schemes in contemporary encyclopedias -- have no more scientific basis than if humans had defined races according to distinctions of height, hair color or right- and left-handedness.

"Race is a social invention," says Audrey Smedley, an anthropologist at Virginia Commonwealth University and chief author of a 1998 American Anthropological Association statement on race that is a manifesto of the new thinking.

"We've been conditioned to the idea that physical differences among people are much more important than they actually are."

Whether the subject is IQ scores or basketball talent, job discrimination or statistics on crime, popular thinking in America seems inevitably to channel into racial categories, chiefly along the black-white fault line.

Decades after Jim Crow laws were repealed, racial segregation persists. Polls show a gulf between whites and blacks in areas from attitudes toward the Clinton sex scandal to favorite TV shows.

"I would never say that race doesn't exist," says Smedley. "It very much exists, and it exists because people invented it."

Most American "Caucasians" today would be surprised to learn that they are so named because an 18th-century German naturalist thought a human skull in his collection -- that of an ethnic Georgian woman from the Caucasus Mountains -- was particularly beautiful.

Many brown-skinned "black" Americans might be taken aback to learn that in Brazil they would not be considered black.

And avid racial theoreticians who assert some genetic racial superiority of intelligence or character, whether white or black, have a hard time squaring their theories with the facts of race-mixing.

Largely because of white masters' sexual exploitation of African slaves, the average African-American has 20 percent to 30 percent European or Native American ancestors, and it is not unusual for an "African-American" to have more European than African ancestry.

By one estimate, the average white American may have 5 percent African or Native American ancestors.

Term frequently misused

But despite the vagaries of race, even scientists routinely use racial terms in ways that inaccurately imply they are scientific, says Paul Stolley, chairman of the department of epidemiology at the University of Maryland medical school.

"I see race misused in every medical textbook," says Stolley, who has launched a sort of one-epidemiologist crusade to stamp out careless references to race by scientists. Stolley gave a seminar at the medical school last month on the issue.

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