SMALL-SCALE POPULATION DYNAMICS

Kin selection has long been thought to be the central driver for the evolution of complex groups. However, since marine animals usually have a larval dispersal phase, small-scale relatedness patterns were assumed to be unlikely in marine ecosystems. The last few decades have shown that larvae often return to their reefs of origin, therefore it is worthwhile investigating whether delayed dispersal, limited dispersal, or kin cohesion during dispersal may lead to elevated relatedness within groups. This work began during my PhD at James Cook University where I worked with the pajama cardinalfish, Sphaeramia nematoptera. Now I am using the emerald coral goby, Paragobiodon xanthosomus, to investigate small-scale relatedness patterns. For both species I surprisingly found elevated values of relatedness within groups. These findings reveal that small-scale relatedness patterns may play a role in social evolution of marine animals. Which dispersal patterns lead to the elevated relatedness within groups of some coral reef fishes is still under investigation.