The study of human genomic diversity in Latin America: nation and population

Genomic science values the genetic diversity revealed by advances in genetic sequencing that allow the detailed mapping of diversity at the level of the individual as well as the population group. This has reinforced the idea that humans share the vast majority of their DNA and that the diversity that does exist cannot be parceled into biological categories that align with older categories of race, which are deeply implicated in the practices and structures of racism. However, the practice of genomic science and medical genetics continues to make use of collective categories and populations. This paper argues that practices in genomic science in Latin America change but also reproduce and even reinforce (by biologizing) familiar and enduring categories of race at different levels in society—among scientists and among nonscientists. The Latin American cases are particular in showing that race is often parsed through ideas about the nation, seen as emerging from the mixture of three ancestral populations. Biologization effects can reinforce the racism (and nationalism) that depend on racialized categories. The paper ends by arguing that these effects are a result of the basic concept of population that has in the past organized and continues today to organize genetic diversity in science practice, despite the ability of genomic technologies to handle genetic diversity at the level of the individual. The grounding role of the population concept is accentuated by Latin American national identities being based on ideas of mixture, which entails a corresponding idea of original purities.