The "new genetics" (or genomics) has penetrated deeply into a broad range of domains in the contemporary world, spawning a technocultural revolution in terms of gene manipulation that has transformed technologies, institutions, practices, and ideologies. In this paper we analyse the debate over the results of a research project ( "Retrato Molecular do Brasil" or "A Molecular Portrait of Brazil") that aimed to shed light on the "genetic origins of Brazilians" based on the sequencing of parts of mitochondrial DNA and the Y chromosome. By focusing on how this survey was received, we will explore some of the new, intense, and abundant forms of relations between "nature/genetics" and "culture/society", in which DNA appears as an key player in the dispute between modalities for interpreting and transforming social and political realities.
Genetics; Race; Social thought in Brazil; Affirmative action; Ethnicity