Jeanette Moss, Geoffrey While

Anthropogenic climatic change will be a major factor shaping natural populations over the foreseeable future. The scope of this issue has spawned the integrative field of global change biology, which is chiefly concerned with identifying vulnerabilities of natural systems to climate change and integrating these into models of biodiversity loss. Meanwhile, there remains considerable latitude for investigating the multiple indirect and nuanced ways that broad-scale shifts in the abiotic environment will impact biological systems. One major unexplored category of effects is on social organisation. While climate has consistently been implicated as a major source of natural selection responsible for facilitating the evolution of complex animal societies, studies directed at testing these links on contemporary climatic time scales have thus far been limited to a select few higher-order, eusocial, taxa. Here, we present the case for how climate change, and specifically rising global temperatures, could catalyze social change at multiple stages of social evolution. We argue that these effects will manifest themselves through a range of subtle, climate-mediated pathways affecting the opportunities, nature, and context of interactions between individuals. We propose a broad conceptual framework for considering these pathways first at the individual level, and then discuss how feedbacks between bottom-up and top-down processes could mediate population-level shifts. We then implement this framework to explore the capacity for climate-mediated shifts in social evolution within three broad categories of social complexity: social group formation, social group maintenance, and social elaboration. For each category, we leverage social evolutionary theory and phylogenetic work spanning diverse systems to describe the pivotal traits that underpin transitions from each level of social complexity. In doing so, we aim to build a case for how short-term individual responses to climate could scale to impart constructive and/or destructive effects on the origins, maintenance, and diversification of animal societies.