Race is good enough for government work: Geneticist Neil Risch, who recently moved from Stanford to UC San Francisco medical school, has done a DNA study of 3,636 people from 15 locations in the US and Taiwan.
Checking a box next to a racial/ethnic category gives several pieces of information about people - the continent where their ancestors were born, the possible color of their skin and perhaps something about their risk of different diseases. But a new study by researchers at the Stanford University School of Medicine finds that the checked box also says something about a person's genetic background.
This work comes on the heels of several contradictory studies about the genetic basis of race. Some found that race is a social construct with no genetic basis while others suggested that clear genetic differences exist between people of different races.
What makes the current study, published in the February issue of the American Journal of Human Genetics, more conclusive is its size. The study is by far the largest, consisting of 3,636 people who all identified themselves as either white, African-American, East Asian or Hispanic. Of these, only five individuals had DNA that matched an ethnic group different than the box they checked at the beginning of the study. That's an error rate of 0.14 percent....
Without knowing how the participants had identified themselves, Risch and his team ran the results through a computer program that grouped individuals according to patterns of the 326 [DNA] signposts. This analysis could have resulted in any number of different clusters, but only four clear groups turned up. And in each case the individuals within those clusters all fell within the same self-identified racial group.
"This shows that people's self-identified race/ethnicity is a nearly perfect indicator of their genetic background," Risch said.
When the team further analyzed each of the four clusters, they found two distinct sub-groups within the East Asian genetic cluster. These two groups correlated with people who identified themselves as Chinese and Japanese. None of the other genetic groups could be broken down into smaller sub-sections. This suggests that there isn't enough genetic difference to distinguish between people who have ancestry from northern Europe versus southern Europe, for example. Risch admitted that few people in this study were of recent mixed ancestry, who might not fall into such neat genetic categories.
I've often pointed out the absurdities inherent in the U.S. Government's race and ethnicity guidelines, but I've also admitted that on the whole they tend to be good enough for government work.
Risch has been working to show that self-identification into broad categories is good enough for medicine, too. I think it's important, though, that doctors keep a relativistic, nesting model of racial groups in mind. For example, although most white subgroups are fairly similar genetically, they should watch out for where they aren't.
Consider alcohol. While doctors who believe that one glass of red wine per day helps the heart shouldn't hesitate to recommend it to Italians and Jews, whose ancestors have been drinking wine for thousands of years, they should ask some questions before recommending alcohol to Swedes and Finns, who often have a hard time stopping once they start drinking. Likewise, the Japanese tend to get drunk fast but also don't have much trouble getting up and getting to work the next morning, but their distant cousins the American Indians have terrible problems with alcohol. Although Risch found that Hispanics lump together pretty well, I would guess that they'd be quite variable in relation to drinking, depending upon whether they inherited Iberian or Amerindian genes for processing alcohol.
Studies contradict view that race doesn’t exist
ReplyDeleteJan. 31, 2005
Special to World Science
Racial differences among people are real, new studies suggest, contradicting claims by some of the world’s leading scientists and scientific institutions that race doesn’t exist.
These experts had said race is merely a “social construct,” or a creation of society’s collective imagination. But the new studies, some of which come from Stanford University in Stanford, Calif., suggest that the way people classify themselves by race reflects real and clear genetic differences among them.
This indicates there is some truth behind the racial distinctions that seem obvious to most ordinary people, the researchers said.
But they added that it’s important to define race correctly, since dangerous misconceptions, such as the notion that some races are superior to others, persist and can serve to excuse racism.
Moreover, previous studies have shown that racial differences between population groups are small, much smaller than variations within the groups themselves. The newer studies didn’t specifically dispute this observation, but simply found that the between-group differences are also clear.
What is true, researchers said in light of the new studies, is that people of different races have different ancestries. This means different genes, since genes are inherited from ancestors.
“The public in general is much more honest” about race than many academics are, “because the general public knows it signifies something rather than nothing,” said Jon Entine, a journalist and author of a critically well-received book, “Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It.”
The title attests to the subject’s controversial nature, and the inflamed passions often triggered by any suggestion that racial differences reflect meaningful biological differences.
The emotions surrounding the debate arise from its origins in the civil rights struggles of the 1960s, which led to widespread efforts to wipe out racism from society. Recognizing the evils that racial classification had created, from slavery to genocides, many tried to fight racism by playing down racial differences as much as possible.
Partly in order to further this goal of ending racial discrimination, some experts began to publicize the view that race didn’t exist at all.
“Race is a social construct, not a scientific classification,” the New England Journal of Medicine, one of the most prestigious medical journals, editorialized on May 3, 2001. “In medicine, there is only one race—the human race.’’
In support of this claim, many scientists cited findings from the Human Genome Project that humans are 99.9 percent genetically alike. These findings recently turned out to be possibly wrong (see exclusive World Science story of Sept. 8, 2004, “New findings undermine basis of ‘race isn’t real’ theory.”)
However, scientists, especially anthropologists, have continued to support the race-as-social-construct position.
The American Anthropological Association’s official statement on race declares: “physical variations in the human species have no meaning except the social ones that humans put on them.” The group’s president-elect, Alan H. Goodman, was quoted in a Baltimore Sun article of last Oct. 10 as saying, “Race as an explanation for human biological variation is dead,” and comparing the race concept to a gun in the hands of racists.
The latest research to challenge the race-as-social-construct theory is a study of 3,636 people from across America and Taiwan, led by Neil Risch, then of the Stanford University School of Medicine and now at the University of California at San Francisco.
It found that people’s self-identified race is a nearly perfect indicator of their genetic background, contradicting the race-as-social-construct view, Risch said.
The study’s authors said it was the largest study of its kind. The participants identified themselves as either white, African-American, East Asian or Hispanic. For each participant, the researchers examined 326 DNA regions that tend to vary between people. These regions are not necessarily within functioning genes—some regions of the genome have no known use—but are simply genetic signposts that come in a variety of forms at the same place.
Without knowing how the participants had identified themselves, Risch and his team ran the results through a computer program that grouped individuals according to patterns of the 326 signposts. This analysis could have resulted in any number of different clusters, but only four clear groups turned up. And in each case the individuals within those clusters all fell within the same self-identified racial group.
“This work comes on the heels of several contradictory studies about the genetic basis of race. Some found that race is a social construct with no genetic basis while others suggested that clear genetic differences exist between people of different races,” a press release from Stanford said.
“What makes the current study, published in the February issue of the American Journal of Human Genetics, more conclusive is its size. The study is by far the largest, consisting of 3,636 people who all identified themselves as either white, African-American, East Asian or Hispanic. Of these, only five individuals had DNA that matched an ethnic group different than the box they checked at the beginning of the study.”
Although it was reported as the largest study to find genetic differences between races, Risch’s study is not the first. Previous studies have found that Ashkenazi Jews are genetically more susceptible than average for Tay-Sachs disease, a fatal nervous system disorder, for instance. Black populations have been found to carry higher levels of a mutation that leads to sickle-cell anemia.
Risch’s study, however, is not only the largest study but also the first to find that these genetic differences are not isolated cases involving a handful of genes, but are spread throughout the genome.
These differences should be of more than passing interest to the medical community, Risch added, because recognizing them can help tailor treatments and prevention programs to better serve specific ethnic groups.
It can also help geneticists avoid skewed results in epedemiological studies, he wrote. For instance, failing to account for the gene-race relationship could make researchers think a particular difference between populations results from genes when in fact it stems from different cultural conditions.
Several scientists who have supported the view of race as a social construct did not respond to requests for comment on the new studies, including officials from the American Anthropological Association and the author of the New England Journal editorial, Robert S. Schwartz.
However, some other scientists reacted without surprise to the new findings.
“As an ordinary citizen educated in biology, it is self-evident that there are genetic differences between people who have been geographically segregated into mating populations, just as there are genetic differences for all species and subspecies,” wrote Michael Wigler, a professor at Cold Spring Harbor Laboratory in Cold Spring Harbor, New York, in an email.
http://www.world-science.net/exclusives/050128_racefrm.htm
New findings undermine basis of “race isn’t real” theory
Posted Sept. 8, 2004
Special to World Science
New research casts doubt on the widely accepted belief that humans are 99.9 percent genetically identical. That statement has been used to argue that race isn't real.
"All human beings, regardless of race, are more than 99.9 percent the same," U.S. President Bill Clinton said in 2000. It turns out that might not be true.
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.”
http://www.world-science.net/exclusives/050128_racefrm.htm