Meeting Abstract
Multilevel selection occurs when a group phenotype influences individual fitness above and beyond the effects of individual traits. Patterns of multilevel selection are largely unexplored, yet understanding what drives multilevel selection is critical for revealing when group traits may evolve. Social networks provide a unique opportunity to study multilevel selection, as social networks quantify complex social interactions at both the individual and group levels. In this study, we used experimental populations of forked fungus beetles (Bolitotherus cornutus) to measure the effects of both individual position within a social network and emergent group-level social network characteristics on individual fitness. We found that male beetles that hold positions of high strength in social networks by interacting more often and with more conspecifics had higher mating success. However, the emergent group-level social network connectedness did not influence male mating success. Conversely, we found that individual strength had no effect on female reproductive success but that females in experimental populations with many social interactions and high network connectedness had lower reproductive success. We additionally manipulated the distribution of fungal resources in the experimental populations to explore how habitat structure influences patterns of multilevel selection. We found that females in more connected networks laid fewer eggs only when fungal resources were distributed in discrete clumps. Our results suggest that patterns of multilevel selection differ across the sexes and across habitat structures.
