Toward a New Vocabulary of Human Genetic Variation

Abstract

Recent genetic variation research has reinvigorated the dispute over the validity of race as a research variable (1-8).Proponents of using race assert that genetic differences and racial classification are strongly associated, and so support the use of race in the design of research and the application of its findings (3,6).Critics cast race as a social construct and counter that putting subjects into racial groups fundamentally misrepresents human genetic variation and hinders research (2,8-9).Several solutions have been offered, such as replacing race with ethnicity (10-11) or with genetic markers (12).However, although these suggestions might apply to certain kinds of research, none provides an overall solution.This is because there are many distinct meanings to the word race, and different ways of using it as a research variable.For example, a popular definition today describes race as a social construct that incorporates beliefs about language, history, and culture (13).Here, race forms the basis on which social identity, traditions, and politics are built.This concept has been promoted as an alternative to an earlier genetic theory of race, which has been scientifically repudiated and rejected, that divided the human species into subspecies that were ranked on the basis of skill, intelligence, and morality (14).However, rejecting race as genetic hierarchy is not tantamount to rejecting the idea that human populations differ genetically.Conceptualizing race as a social construct has helped to undermine racism by eliminating its alleged natural basis.However, it has also had the unintended consequence of eliminating a legitimate basis for discussion of population-based genetic differences.Insistence that there is no such thing as race in a genetic or biological sense, as well as the lack of an alternative term for discussing genetic diversity leaves those who wish to discuss genetic diversity without a functional vocabulary (15)(16)(17)(18).Two points should help to clarify these issues.First, the debate in genetic variation research over race as a research variable is not a debate over whether human populations differ genetically.Rather the debate is over the scientific, clinical, and social significance of labeling genetic differences as race, as something else, or not at all (19).Second, many of the disagreements about race and genetics are fostered by confusion over the relationship of these two concepts.For example, recent studies have examined DNA samples from various populations and clustered them into groups based on identity of DNA sequences at several loci.In some studies (20), but not others (8), genomes examined by this method do sort out in a way that reflects race as social construct, depending on how many or which genetic loci are compared.It is not that race exists in one population and not in another.Rather, it may be that the appearance of clustering is a function of how populations are sampled (21), of how criteria for boundaries between clusters are set, and of the level of resolution used.In the same