Conclusions
Sociality has repeatedly arisen as an adaptive response to extreme and variable environments. The same features of sociality that have enabled its evolutionary success in these conditions may render social organisms particularly resilient to climate change (Blumstein et al., 2022; Fisher et al., 2021; Komdeur and Ma, 2021; Menzel and Feldmeyer, 2021). In many contexts, changing climate will favor social bees with long activity periods, generalist diets, and behavioral adaptations (e.g., communication and thermoregulatory strategies) that facilitate survival in stochastic environments. In other cases, extreme climate conditions may select for life history patterns and expanded physiological tolerances common to solitary bees. Our understanding of these effects is currently data-limited and should be expanded in part through open sharing of bee functional trait data (especially physiological tolerance and social behavioral data), which will enable meta-analyses of the traits co-occurring with sociality and their impacts on climate change responses. Beyond these differential impacts, climate change can also shape social evolution itself by shifting the abiotic and biotic selective pressures that determine the fitness outcomes of different social strategies. The direction of these shifts will be largely heterogeneous within and across taxa, depending on such factors as local climatic variability and the extent to which plasticity governs responses to environmental change. Experimental studies of socially polymorphic bee species (e.g., common garden experiments, reciprocal transplants, and studies manipulating environmental conditions) will extend our understanding of these evolutionary consequences. Future work in this area has the potential to clarify interactions between climate change and sociality at multiple levels and timescales, from shifting distributions of social bees to evolutionary transitions in social organization.