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Population differentiation in the context of Holocene climate change for a migratory marine species, the southern elephant seal
Author(s) -
Corrigan L. J.,
Fabiani A.,
Chauke L. F.,
McMahon C. R.,
Bruyn M.,
Bester M. N.,
Bastos A.,
Campagna C.,
Muelbert M. M. C.,
Hoelzel A. R.
Publication year - 2016
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/jeb.12870
Subject(s) - vicariance , biology , allopatric speciation , ecology , isolation by distance , reproductive isolation , holocene , context (archaeology) , climate change , population , range (aeronautics) , genetic structure , land bridge , biological dispersal , phylogeography , evolutionary biology , paleontology , genetic variation , phylogenetics , demography , biochemistry , materials science , sociology , composite material , gene
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 mt DNA 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.