Building on the biocultural syntheses: 20 years and still expanding.

Building a New Biocultural Synthesis: Political Economic Perspectives in Human Biology called for an integration of political economy with ecological and adaptability perspectives in biocultural anthropology. A major goal of this volume was to explore the utility of including political-economic and sociocultural processes in analyses of human biological variation, nutrition, and health. A second goal was to enhance collaboration among subfields and work against the "chasm" that separated complementary perspectives in cultural and biological anthropology. Twenty years hence, new ways to link social inequalities and human biology have emerged in part through contributions of developmental origins of health and disease, epigenetics, microbiomes, and other new methods for tracing pathways of embodiment. Equally important, notions of "local/situated biologies" and "reactive genomes," provide frameworks for understanding biology and health at the nexus of ecologies, societies, and histories. We review and highlight these contributions toward expanding critical approaches to human biology. Developments over the past two decades have reinforced the central role of social environments and structural inequalities in shaping human biology and health. Yet, within biocultural approaches, a significant engagement with historical, political-economic, and sociocultural conditions remains relatively rare. We review potential barriers to such analyses, focusing on theoretical and methodological challenges as well as the subfield structure of anthropology. Achieving politically and socially contextualized and relevant critical biocultural approaches remains a challenge, but there is reason for optimism amid new theoretical and methodological developments and innovations brought by new generations of scholars.