Investigating Ethnicity
MARK HENDERSON
The Times (UK), 11/20/2004
New research shows that race is largely meaningless- so why don't we believe it?
It is fashionable in scientific circles to argue that race does not really exist.
The Marxist biologist Richard Lewontin argued back in 1972 that the concept had neither social value nor genetic significance- and the findings of the Human Genome Project have convinced many people that he was largely right.
The evidence of humanity's genetic blueprint indeed suggests that race as it is popularly defined is biologically meaningless. People of all backgrounds share more than 99.9 per cent of their DNA and there is more variation within stereotypical racial groups than there is between them. An African is likely to be as similar genetically to a Swede as to someone from the next village. Skin colour is a poor marker for ancestry, fluctuating widely within populations that society calls "black", "white" or "Asian". We all evolved too
recently from the same "bottleneck" of people- and have interbred too often- for our genomes to have diverged that much.
Pseudoscientific notions of difference that have underpinned racist ideologies, from Hitler to Idi Amin, have thus been refuted by facts. Yet Lewontin's contention that race is an empty term strikes most people as preposterous. Racial differences are recognised by all cultures and the
traits -skin pigmentation, hair and facial shape -are largely inherited. Ethnicity is clearly something more than a social construct, even if its edges are hard to pin down.
It can also have medical meaning. It is undeniable that certain racial groups have a higher incidence of certain diseases: sickle- cell anaemia and hypertensive heart disease among those of African background, for example, and multiple sclerosis among Caucasians.
Some drugs have different effects: the antipsychotic clozapine is more likely to trigger serious side-effects in Afro-Caribbeans and last week saw the launch of BiDil, a heart drug licenced only for America's black community.
There is little doubt that genes play a part in this. But, as Armand Leroi of Imperial College, London, said this week in the Natural History Museum's Pfizer Annual Science Lecture: "The scientific study of race is now practically non-existent."
The Human Genome Diversity Project, which aimed to map our genetic variety, collapsed three years ago amid misplaced allegations of racism. Though genetics is usually a well-funded branch of research, money for investigations of ethnicity is rarely forthcoming. Fears about a revival of the flawed science of the 1930s are holding the field back.
This is a great shame, as this sort of research will be crucial if we are to unravel the medical significance of human ancestry. A special edition of the journal Nature Genetics last month explained that at present race is just a
crude surrogate for genetic variation. Any insights it offers work only on average across large populations and not for individuals. This can make it a handy short- cut to diagnosis and prescription but a fallible one. A doctor placing too much trust in ethnicity will tend to miss the occasional Caucasian child with a "black" disease like sickle-cell, or overlook a suitable drug that's normally recommended for a different racial group.
Scientists need to get beyond race as a proxy for inheritance and reach the individual genes and clusters of genes that lie beneath. But to do this, they must be allowed to study genetic diversity. There is no reason to assume this will feed racial prejudice: Leroi, indeed, makes an excellent case that the reverse is true.
"The cracks of ignorance leave an intellectual vacuum in which socially unjust theories can flourish," he says.
Socially unjust medicine thrives in such a vacuum too: most drugs have always been designed for and tested on white Europeans, with little regard for their effects on other ethnic groups. If we want the genomic revolution to benefit all races, we have a duty to examine their genetic variety. The most racist course would be to ignore it.
Mark Henderson is the Times science correspondent