Race gene does not exist, say scientists

E-mail E-mail this article
Print Print this article

Other links
The Genome Project: a recipe for humanity

The human genome, to be published in nearly complete form this week in the journals Nature and Science, stands to cure cancer, prevent mental illness, and even, as one local researcher joked, locate the "don't-ask-for-directions gene" on the Y chromosome unique to men.

But billions of pieces of genetic code sequenced thus far are notable for what they don't appear to contain: a genetic test to tell one race of people from another.

All scientific signs point to the conclusion that race doesn't exist. The further scientists go in sequencing the genome - the complete catalog of the genetic material found in every human cell - the more they realize there is no biological basis for our most contentious and divisive of social categories.

Moreover, science has repeatedly found far more variation within a given racial group than between racial groups.

And the guiding principle of race, skin color, is small and superficial in scientific terms.

Genetic research from the mid-'90s suggests much of our skin color comes from variations of just one of tens of thousands of genes. The gene may be involved in melanin production, leading to variations in the color of human skin and hair.

If that's true, say University of Washington geneticists Kelly Owens and Mary-Claire King, this variation at a single, small genetic site has been "the cause of enormous suffering."

"Of course, prejudice does not require a rational basis, let alone an evolutionary one," Owens and King wrote in a 1999 article in Science. "But the myth of major genetic differences across `races' is nonetheless worth dismissing with genetic evidence."

"The races really differ very little from one another - that's quite a striking point that's come out of the comparative (genetic) studies that have been made," said Leroy Hood. Now the head of Seattle's Institute for Systems Biology, Hood is one of the original participants in the Human Genome Project, the federally funded group whose work is being published in Nature.

Mapping the genome is an accomplishment that Hood ranks above landing a man on the moon. It is, he said, a genetics parts list; a fundamental description of our basic being, in digital form; a "Periodic Table of life."

The work of Hood's group is combined with the work of Celera Genomics, the private genetic-research company whose genome sequence is to be published in Science this week.

Celera used DNA from three females and two males who identified themselves as Hispanic, Asian, Caucasian or African American.

"In the five genomes, there is no way to tell one ethnicity from another," Celera President Craig Venter said when the genome's rough draft was announced at the White House in June. "Society and medicine treat us all as members of populations, whereas as individuals we are all unique and population statistics do not apply."

While Celera's sampling explored a broad cross section of groups it was not deep, having drawn DNA from so few individuals. The DNA of more people will be surveyed over the next decade as sequencing tools get faster and as researchers search among populations for the genetic influences on things like disease and clues to our origins and evolution.

Even then, the chance of finding a race gene is remote, as is the chance of finding a genetic basis for characteristics often ascribed to certain races.

"I would certainly be shocked - utterly shocked - if there were any fundamental differences whatsoever in the traits we value most: intelligence, physical capacity, things like that," Hood said.

Which is not to say race does not exist as a cultural reality, evident in racial profiling, persistent stereotypes, discussions of affirmative action and debates over differences in athletic ability. It is evident in the varying housing, education and job opportunities available to people who have been categorized by skin color.

"The issue is a bloody cultural mess," said Nancy McKee, a Washington State University anthropologist.

Much of this "mess" was created with the help of science, which in the 19th century developed elaborate methods of categorizing people by race - methods since proved faulty.

Until then, race was a folk notion that grew out of the ancient theorem of the Great Chain of Being and came in handy for classifying people subjugated by colonialism, the American Anthropological Association (AAA) noted in its 1998 Statement on Race, an attempt to clarify the term's cultural roots.

Science, no stranger to the biases of popular culture, took to developing elaborate racial categories that treated Africans, Indians and Europeans as separate species. Africans, the AAA study found, were believed "the least human and closer taxonomically to apes."

Caucasian was considered the norm and ideal; anything else was inferior. At one time, Irish people were not considered white, nor were Jews, Poles or southern Europeans, said Richard White, a former UW history professor now at Stanford University.

But this thinking did not anticipate certain pitfalls. For one, all humans can be traced to Africa. Moreover, no group or race was pure or distinct; the globe is too small and humans wander and breed too widely for that to happen.

"You cannot demarcate populations because populations all over the world blend into each other," said Audrey Smedley, a professor of anthropology at Virginia Commonwealth University and author of the AAA's statement.

Where scientists once saw race in terms of black and white, anthropologists in the mid-20th century saw a continuum of variations with no clear dividing lines between races or populations. Moreover, environment came to be seen as a far larger player in determining an individual's characteristics, as happened when researchers probed the origins of sickle-cell anemia in the 1950s.

The disease, a disorder in which red-blood cells take on a curved shape that clogs vessels, is commonly believed to occur only in African Americans, as if it were some sort of racial genetic marker. At one time its gene was called "the Negro gene," said Frank Livingstone, a University of Michigan anthropologist and sickle-cell pioneer.

The sickle-cell gene is actually a genetic mutation, an act of natural selection that helps fight malaria. Livingstone showed that sickle-cell anemia occurred in "clines," or gradients of change, across geographic regions. The disease was present in tropical Africa, where malaria is widespread, and also in the malaria-infested Arabian Peninsula and southern India.

"Genetic variation in the Old World did not exist as a racial trait," Livingstone said yesterday from his Ann Arbor home. "There are more sickle-cell carriers in India than there are in Africa. The idea of race just didn't make sense. The Zulus had no frequency of the disease, and they're African."

Other genetic research has shown that most physical variation - more than 80 percent - occurs within what we have come to define as a racial group. But between what we think of as distinct racial groups, genes vary only about 10 percent of the time.

Still, the idea of different biologically-based human races has stuck.

White, the Stanford historian, said he has spent the past 10 or 15 years teaching students that race is a social construction. They often greet his lessons with disbelief, as if to say, "we know what we know."

In a society so defined by race, he said, "everything we see, everything we understand, is bound up in this idea of race and it's very hard to give up."

The AAA urged the U.S. Office of Management and Budget to drop the use of the term "race" in federal reports and the 2000 census and replace it with "more correct terms related to ethnicity, such as `ethnic origins.' "

"That's where we should be going, realistically," said Michael Blakey, a Howard University anthropologist, who pushed for the changes.

But the new census had respondents mark one or more of 14 boxes representing six races and subcategories or "some other race," with 63 racial possibilities. The groupings were criticized for both confusing the issue and continuing to rely on racial categories.

Yet Blakey acknowledged the position of civil-rights groups who see the importance of continuing to record racial designations to remedy inequities in employment, housing and health care for people long discriminated against on the basis of skin color.

Eric Sorensen's phone number is (206) 464-8253. His e-mail is esorensen@seattletimes.com.