  With the HGP reference sequence available as a basis for comparison, attention has shifted to the genetic variation within the species that evolutionist critics accused the project at the outset of ignoring. Humans have been found to be 99.9 percent alike, with common sequence variants occurring every 1000 bases. There is interest in identifying the sites of the genome where variation occurs, the frequency of these differences, and their significance. The social significance attaching to such research was foreseen during the early years of the project. Scientist David Baltimore predicted that the HGP would reveal that the belief that “we are all equal, all the same” is a myth: “We are going to have to come to terms with the fact that we are all born with different talents and tendencies” (in Cooper 1994, p. 320). Similarly, philosopher Marc Lappé (1994) raised the possibility that the HGP could reveal group differences—with sequences localized to particular groups or varying in frequency among groups—and that any such differences in the genetic lottery would raise significant ethical implications for health care and social  policy.[17] But the conceptualization of this variation also presents challenges—for example, in distinguishing between normal and abnormal genetic variation (Gannett 2003a), or drawing population boundaries in the constitution of individual versus group differences (Gannett 2003b). Pharmaceuticals are the most powerful engine driving post-HGP diversity research, and though “personalized medicine” was touted as a benefit of the HGP, en route, a detour via the study of group genetic differences has been taken. For example, the International HapMap Project, in order to compile a map adequately dense with SNP markers to permit the identification of genes implicated in common diseases and drug responses, sampled the DNA of four populations (European-Americans in Utah, Yoruba in Ibadan, Nigeria, Japanese in Tokyo, and Han Chinese in  Beijing).[18] Likely due to lessons learned from the difficulties experienced by the Human Genome Diversity Project (see Reardon 2004), attempts were made to involve representatives of these groups in the planning of research through “community engagement” and “community consultation.” These efforts raise conceptual questions not only about the relations between what are ostensibly distinct social and biological groups (Gannett 2003b, Juengst 1998), but what makes a “community” (Davis 2000). Now that “group” genetic differences have become of interest to more than just evolutionary biologists and population geneticists, impetus is provided to longstanding debates about whether race is biologically real or socially constructed and more recent ones concerning the appropriateness of the use of racial categories in biomedical research (Gannett 2005; Root 2003).