Genomics resources that use samples from identified populations raise scientific, social and ethical issues that are, in many ways, inextricably linked. Scientific decisions about which populations to sample to produce the HapMap, an international genetic variation resource, have raised questions about the relationships between the social identities used to recruit participants and the biological findings of studies that will use the HapMap. The sometimes problematic implications of those complex relationships have led to questions about how to conduct genetic variation research that uses identified populations in an ethical way, including how to involve members of a population in evaluating the risks and benefits posed for everyone who shares that identity. The ways in which these issues are linked is increasingly drawing the scientific and ethical spheres of genomics research closer together.