This project explored the production and negotiation of difference in Soviet/Russian human biology and ecology from 1970 to present. The investigation of human ecology in terms of “biomedical problems”—in particular effects of the physical environment—was a key research area in Soviet/Russian sciences during and after the Cold War. Biophysicists especially focused on populations that were exposed to “extreme conditions”; this included health effects of fallout exposures, human physiology in Arctic climates, as well as space medicine. Involved disciplines and methods ranged from experimental medicine to population genetics and medical geography and from the study of molecular markers to field surveys: anthropologists engaged in mapping human variation according to biological markers; public health scientists designed comprehensive monitoring systems; biophysicists and epidemiologists took advantage of environmental differences in terms of “quasi-experimental” opportunities for the study of human biology. This project focused on scientific practices—from study designs, collection of data and samples, data organization and processing, to biostatistical modelling and visualization of results. Examining the effects of ever more differentiations along novel biomarkers and other subgroup categories also shed light on the micropolitics of difference at work in recent globalized biomedical research.