NYTimes | In 1942, the anthropologist Ashley Montagu published “Man’s Most Dangerous Myth: The Fallacy of Race,”
an influential book that argued that race is a social concept with no
genetic basis. A classic example often cited is the inconsistent
definition of “black.” In the United States, historically, a person is
“black” if he has any sub-Saharan African ancestry; in Brazil, a person
is not “black” if he is known to have any European ancestry. If “black”
refers to different people in different contexts, how can there be any
genetic basis to it?
Beginning in
1972, genetic findings began to be incorporated into this argument. That
year, the geneticist Richard Lewontin published an important study of
variation in protein types in blood. He grouped the human populations he
analyzed into seven “races” — West Eurasians, Africans, East Asians,
South Asians, Native Americans, Oceanians and Australians — and found
that around 85 percent of variation in the protein types could be
accounted for by variation within populations and “races,” and only 15 percent by variation across them.
To the extent that there was variation among humans, he concluded, most
of it was because of “differences between individuals.”
In
this way, a consensus was established that among human populations
there are no differences large enough to support the concept of
“biological race.” Instead, it was argued, race is a “social construct,”
a way of categorizing people that changes over time and across
countries.
It is true that race is a
social construct. It is also true, as Dr. Lewontin wrote, that human
populations “are remarkably similar to each other” from a genetic point
of view.
But
over the years this consensus has morphed, seemingly without
questioning, into an orthodoxy. The orthodoxy maintains that the average
genetic differences among people grouped according to today’s racial
terms are so trivial when it comes to any meaningful biological traits
that those differences can be ignored.
The
orthodoxy goes further, holding that we should be anxious about any
research into genetic differences among populations. The concern is that
such research, no matter how well-intentioned, is located on a slippery
slope that leads to the kinds of pseudoscientific arguments about
biological difference that were used in the past to try to justify the
slave trade, the eugenics movement and the Nazis’ murder of six million
Jews.
I have deep sympathy for the concern
that genetic discoveries could be misused to justify racism. But as a
geneticist I also know that it is simply no longer possible to ignore
average genetic differences among “races.”
Groundbreaking
advances in DNA sequencing technology have been made over the last two
decades. These advances enable us to measure with exquisite accuracy
what fraction of an individual’s genetic ancestry traces back to, say,
West Africa 500 years ago — before the mixing in the Americas of the
West African and European gene pools that were almost completely
isolated for the last 70,000 years. With the help of these tools, we are
learning that while race may be a social construct, differences in
genetic ancestry that happen to correlate to many of today’s racial
constructs are real.
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