In recent years, postgenomic research, and the fields of epigenetics and microbiome science in particular, have described novel ways in which social processes of racialization can become embodied and result in physiological and health-related racial difference. This new conception of biosocial race has important implications for philosophical debates on the ontology of race. We argue that postgenomic research on race exhibits two key biases in the way that racial schemas are deployed. Firstly, although the ‘new biosocial race’ has been characterized (...) as social race entering into biological processes, it is only particular aspects of social race that are taken to cross the biosocial boundary, resulting in a distorted view of the social component of biosocial race. Secondly, racial categories are assumed to be stable across time and space. This assumption is epistemically limiting, as well as indicating a reliance on a fixed racial ontology. However, the causal pathways for the embodiment of social race, and the different possible modes of embodiment, that postgenomic science is uncovering themselves present a challenge for fixed or static racial ontologies. Given these tensions, we argue that the emerging picture of a shifting landscape of entanglement between the social and the biological requires us to increase the complexity of our ontologies of race, or even embrace a deflationary metaphysics of race. (shrink)