Concerns with the relative unity and diversity of the discipline of anthropology have a long history. As early as 1936 Boas remarked that for a few decades physical and social anthropology had been drifting ‘more and more apart’ (Boas 1940: 172), a theme repeated three decades later in Alland’s introduction to what he called ‘Darwinian anthropology’, separating ‘the cultural traits which develop … against the background of biologically determined human nature’ (Alland 2009: 236). Despite repeated recapturing of anthropology in recent decades (see, for example, Fox 1991, Segal and Yanagisako 2005), the two theoretical tectonic plates of biology and physiology, on the one hand, and, on the other, culture and society remain more or less intact. European biological and social anthropologists, for instance, continue to operate on very different terrains in the disciplinary landscape. In the North American context, there are recent cases of departmental fission along these lines, defying the classical four-field approach. As Schultz remarks, to challenge (and by the same token, to defend) the four-field approach is simply to ‘muddy the waters’ (2009: 227), avoiding the real issue of the reality of the two-field divide which splits the study of humans more generally, in practically every academic environment on the planet. Almost universally, anthropology is taught and practised as the dual field of the social and biological, variously constituted and articulated in relation to other fields, depending on historical and institutional context.

A series of recent intellectual developments have converged to challenge dominant thinking on the disciplinary structures of anthropology and, more generally, the divide between the life sciences and the humanities, fashioning a novel approach to the development and evolution of humans and other species. It seems time now to draw upon these developments to outline new avenues for the study of humans and explore opportunities for their advance, moving beyond mere critiques of dualisms and the anthropological ‘mirage’ of space between nature and nurture identified by Fox Keller (2010). Such an enterprise, the contributors to this book suggest, both entails a ‘biosocial’ rethinking of boundaries and a processual, relational perspective on becoming.