SoEvoFish · Coral reef fish shape our understanding of social evolution

Complex societies where some individuals forego reproduction, pose an evolutionary conundrum. There have been numerous attempts over past decades to explain why individuals capable of reproduction would give up the chance to propagate their own genes. Yet, there remain debates about the relative importance of various factors in shaping social evolution. Additionally, a clear bias towards the study of terrestrial animals prevents us from viewing the whole picture. The overall objective of the proposed study is to build a more general framework for social evolution in animals, by conducting novel studies of two model coral reef fish systems. Specifically, we will conduct in situ investigations on two species: the clown anemonefish Amphiprion percula (f. Pomacentridae) and the coral goby Paragobiodon xanthosomus (f. Gobiidae). Both species are ideal models as they form groups consisting of a breeding pair and one or several non-breeding subordinates. We will test three hypotheses that explain the social evolution of these species: kin selection, whereby nonbreeders gain fitness benefit by helping close relatives reproduce; ecological and social constraints, whereby non-breeders stay in the group and do not contest for breeding positions because of poor alternative options both outside and inside the group; and synergistic effects, where group augmentation leads to large groups benefiting all members. The project will be conducted at Boston University (BU) and the University of Exeter (UoE), bringing together leading experts of social evolution in fish, Prof Pete Buston, and in mammals and insects, Prof Mike Cant. Thus, the project will promote a two-way transfer of knowledge, and enable us to form a more complete picture of social evolution in the animal kingdom. The proposed work will provide extensive training for the experienced researcher, Dr. Theresa Rueger, and enable her to build on her existing expertise to develop an independent career in research.