Loin de l'équilibre. Dynamiques de la diversité en écologie et en sociologie

The chapter compares some recent developments in the representation and prediction of the dynamics of diversity - i.e., its production and maintenance in nonequilibrium systems - in the social sciences (at the case of cultural diversity) and in ecology (biodiversity). Advancements in the modeling of multilayered networks, together with new enabling technologies, have lately shifted the focus in both fields on "higher order" interactions as an additional layer of complexity which must be taken into account to understand these dynamics. These developments confirm the analytic and heuristic fertility of the systemic approach, as providing a common set of tools for formalizing complex adaptive systems, but they also highlight deeply entrenched differences between these two typologies of systems, ultimately driven by the distinct forces, forms of agency and relevant reference environment. The broader scope of the present comparative analysis of higher order interactions in social science and ecology is therefore to revive the original antireductionist stance of System Theory, as the precondition for a pluralist integration of phenomena belonging to ontologically and epistemologically irreducible levels, for a more effective management of the greater complexity driven by their interlacing, and, last but not least, for better counteracting the danger of the loss of diversity to which both systems are increasingly exposed.