OF ALL the genetically determined traits that we might one day hope to control, skin colour is surely one of the most politically explosive. What might the consequences be for society if we could alter our skin colour at will? Would it prove the superficiality of race, bringing centuries of prejudice to an end? Or might it exacerbate such bias by creating a bitter divide between those who can afford to lighten their skin and those who cannot?
With the recent discovery of several gene variants that play a sizeable role in human skin pigmentation, we are getting close to finding out. Skin colour is determined by the amount and distribution of the pigment melanin in compartments within our skin cells called melanosomes. Mutations in the proteins involved in this process, such as tyrosinase (Molecular Biology and Evolution, ) and SLC24A5 (), result in significantly lighter skin. This week, the SOX9 protein was added to the list (Proceedings of the National Academy of Sciences, ).
Disturbingly, this research is going ahead with little attention to race or to the social impacts that being able to manipulate skin colour might have. An article published in New 杏吧原创 earlier this year exemplifies this trend. Jessica Marshall expends almost 3000 words reviewing the genetics of skin colour, noting that 鈥渙ur skin colour might one day become almost as easy to change as hair colour is today鈥�, but she doesn鈥檛 once mention the dreaded 鈥淩鈥� word (10 March, p 34). Stanford geneticist Gregory Barsh has been reported as saying that the latest developments 鈥渋ndicate how the genetics of skin colour variation is quite different from, and should not be confused with, the concept of race鈥�. Nina Jablonski, author of , apparently agrees: 鈥淪kin does not equal race, period.鈥�
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This might be a convenient argument for scientists wanting to carry out research into pigment genetics without having to deal with troublesome ethical debates. In the real world, however, race and skin colour are often understood to be synonymous. Society has long tended to distribute resources according to racial differences, as interpreted through skin tone. For example, Joni Hersch, an economist at Vanderbilt University Law School in Nashville, Tennessee, has studied data on how immigrants to the US fare. She found that those who have the lightest skin earn 8 to 15 per cent more than those with the darkest skin, controlling for factors such as country of origin, occupation and fluency in English ().
Given these social and economic pressures, genetic advances in this area are likely to translate quickly into commercial products. Indeed, chemical skin-lightening creams already have global popularity, despite their health risks and limited efficacy. Ads for products such as reinforce the message that fair skin is necessary for love and success.
In the next few years, we may see much more effective lotions based on the technique of RNA interference, in which small molecules of RNA might switch off specific genes involved in melanin production or transport to alter skin colour. The cosmetics company Avon has already applied for a for using RNA interference to switch off the tyrosinase gene. A little further down the line it may be possible to screen out embryos with a genetic predisposition to dark skin. Greater control over skin colour may quickly become less about individual vanity and more about redesigning current and future demographics according to dubious social preferences.
鈥淚t may eventually be possible to screen out embryos with a predisposition to dark skin鈥�
Before all this becomes a reality, we should ask what the ability to alter skin colour might mean as long as racial inequality based on it persists. How can regulators, who have a duty to ensure that irrational market preferences don鈥檛 harm minorities, make sure such developments don鈥檛 reinforce society鈥檚 preference for white skin?
The situation also draws attention to a broader point: the reluctance of some researchers to acknowledge the social context and impact of their work. Some scientists seem to believe that they can simply state that skin colour has nothing to do with race and thus make it so. We all need to anticipate the social challenges raised by this work and think about a question that should be at the centre of more policy debates: what does it mean for biotechnology to develop in the public interest?
Research into pigmentation genetics should of course go forward: it improves our understanding of who we are and could lead to treatments for pigmentation disorders. As the science advances, however, policy-makers must develop a regulatory framework that does not allow innovations to exploit the deep-rooted bias that society has towards certain groups. It would surely be a pity for any aspect of biotechnology research to develop in ways that help people to profit from racial prejudice.
