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RETURN TO THE WORLD SCIENCE HOME PAGE New findings undermine basis of “race isn’t real” theory
Sept.
8,
2004
For years, mainstream scientists have said there are no real racial differences among people. Race is purely a “social construct” – in other words, it’s imaginary, some have argued. But two new studies raise doubts about a key calculation on which this argument rests. This calculation, often cited publicly by world-renowned geneticists, is that all humans are more than 99.9 percent genetically identical. As geneticist Eric Lander told Wired Magazine in February, 2001, any two humans are “more than 99.9 percent identical at the molecular level. Racial and ethnic differences are all indeed only skin deep.” Even U.S. President Bill Clinton said, in a 2000 speech: “All human beings, regardless of race, are more than 99.9 percent the same.” But two new studies suggest that percentage is too high, researchers say – although it's unclear whether the real number is much lower, or just a little. “The 99.9 percent number is pure nonsense,” wrote Michael Wigler, of Cold Spring Harbor Laboratory, New York, in a recent email. “I will not say anything more about it.” However, he added, “it is true that humans are more like each other than many other species.” Wigler is a co-author of one of the two studies, which is published in the July 23 advance online edition of the prestigious research journal Science. In it, the researchers wrote that they were surprised to find large-scale differences in human DNA. “There is considerable structural variation in the human genome [genetic code], most of which was not previously apparent,” they wrote. Some researchers don't think the new findings should change the 99.9 percent figure that much. “Taking all types of DNA variation into consideration and looking at the entire 'content' of the genome, I would now say we are 99.7-99.8 percent identical,” said Stephen W. Scherer of the Hospital for Sick Children in Toronto. Scherer co-authored another study, whose conclusions were similar to those published in Science. His was published in the Aug. 1 advance online issue of the research journal Nature Genetics. Scherer declined to say whether he thinks the findings mean race is real. Lander – a researcher who has been quoted in published reports giving the 99.9 percent figure, and who works with the Whitehead Institute in Boston – didn’t respond to phone calls and emails requesting comment for this story. His secretary said he was abroad. Also unreachable was Craig Venter, chairman of the Institute for Genomics Research in Rockville, Md., U.S.A. He was president of a company whose research produced the 99.9 percent figure in 2001, Celera Genomics. He didn't return phone calls or repeated emails. In one of the new studies, Wigler’s group sampled DNA from 20 people from around the world. They detected 76 major differences among the people, differences known as copy number polymorphisms. This means that some sections of genetic code are repeated, but the number of repetitions vary among people. This “could explain why people are different” – although whether it in fact does explain it, is unknown, said Scherer, whose team reached similar findings to those of the Cold Spring Harbor group. “At first we were astonished and didn't believe our results because for years we had been taught that most variation in DNA was limited to very small changes,” Scherer said. But later, he added, he learned Harvard University researchers were making similar observations, so the groups combined their data and reached the same conclusion. The Cold Spring Harbor team found that these changes affected the code for 70 genes. These included genes involved in Cohen syndrome – a form of mental retardation – as well as brain development, leukemia, drug resistant forms of breast cancer, regulation of eating and body weight. The “race-isn't real” proponents have other arguments besides the 99.9 percent figure to back up their case. But that figure has become one of the most prominent pieces of their argument since about four years ago, when the number came out from scientists associated with the Human Genome Project, a 13-year program to map the human genetic code. Another key argument that scientists have made to back up the statement that race isn’t real, is that most of the genetic differences between people are local ones, not differences between "races." In other words, as the U.S. public television channel PBS states on its website: “two random Koreans are likely to be as genetically different as a Korean and an Italian.” However, those findings came out before the new genetic variation studies. Some researchers have suggested that the type of genetic variation these studies identified – the copy number differences – could be used as a new test for comparing the relative importance of local and group variation. “My guess is we will see all types of LCVs [large-scale copy variations], so there will be some population or group 'prevalent'” ones, Scherer said. Some people disputed whether any percentages, whether 99.9 or otherwise, should be cited as a measure of human differences. The figure is “entirely meaningless as a measure of functional population differences,” said Miami University’s Jon Entine, author of “Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It,” in an email. “Dogs and wolves are 100 percent identical but functionally different,” Entine added. “Rats are about 95 percent the genetic equivalent of humans. These are ridiculous statements, although technically accurate. The use of the 99.9 percent figure by the popular press and scientists is, frankly scandalous.” Whether or not race is real, researchers said, it doesn’t mean one race is better than another. “Great abuse has occurred in the past with notions of 'genetic superiority' of one particular group,” Stanford University's Neil Risch wrote in the July 1, 2002 issue of the research journal Genome Biology. “The notion of superiority is not scientific, only political, and can only be used for political purposes.” Front image courtesy Utah Department of Community and Economic Development * * * * *
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