Familial social structure and socially-driven genetic differentiation in Hawaiian short-finned pilot whales

Social structure can have a significant impact on divergence and evolution within species, especially in the marine environment, which has few environmental boundaries to dispersal. On the other hand, genetic structure can affect social structure in many species, through an individual preference toward associating with relatives. One social species, the short-finned pilot whale (Globicephala macrorhynchus), has been shown to live in stable social groups for periods of at least a decade. Using mitochondrial control sequences from 242 individuals and SNPs from 106 individuals, we examine population structure among geographic and social groups of short-finned pilot whales in the Hawaiian Islands, and test for links between social and genetic structure. Our results show that there are at least two geographic populations in the Hawaiian Islands: a Main Hawaiian Islands (MHI) population and a Northwestern Hawaiian Islands/Pelagic population (FST and ΦST P < 0.001), as well as an eastern MH...