This article explores human genetic diversity research east of what was the iron curtain. It follows the technique of “genogeographic mapping” back to its early Soviet origins and up to the post-Soviet era. Bringing together the history of genogeographic mapping and genealogies of “nationality” and “race” in the USSR, I discuss how populations and belonging were enacted in late Soviet biological anthropology and human genetics. While genogeography had originally been developed within the early Soviet livestock economy, anthropologists, public health scientists, (...) and medical geneticists reanimated the technique in the late 1960s after the end of the Lysenko era and its ban on classical genetics. In the 1970s, population geneticists pursued a project to compile all genetic data on the USSR population, resulting in a “genogeographic atlas,” consisting of series of tables as well as maps projecting genetic markers onto geographic grids. Following the post-Soviet trajectories of these maps, I examine the ways in which human genetic diversity studies realign with renegotiations of difference in today’s Russian Federation. The exploration of the Soviet case of human genetic diversity research contributes to our understanding of the varied ways in which racializing discourses were entangled in the project of modernization. (shrink)