Data from: Population differentiation in the context of Holocene climate change for a migratory marine species, the southern elephant seal

Understanding observed patterns of connectivity requires an understanding
of the evolutionary processes that determine genetic structure among
populations, with the most common models being associated with isolation
by distance, allopatry or vicariance. Pinnipeds are annual breeders with
the capacity for extensive range overlap during seasonal migrations,
establishing the potential for the evolution of isolation by distance.
Here we assess the pattern of differentiation among six breeding colonies
of the southern elephant seal, Mirounga leonina, based on mtDNA and 15
neutral microsatellite DNA markers, and consider measures of their
demography and connectivity. We show that all breeding colonies are
genetically divergent and that connectivity in this highly mobile pinniped
is not strongly associated with geographic distance, but more likely
linked to Holocene climate change and demographic processes. Estimates of
divergence times between populations were all after the Last Glacial
Maximum, and there was evidence for directional migration in a clockwise
pattern (with the prevailing current) around the Antarctic. We discuss the
mechanisms by which climate change may have contributed to the
contemporary genetic structure of southern elephant seal populations and
the broader implications.