Data from: Paleoclimatic changes resulted in range expansion and subsequent divergence in brown fur seals, Arctocephalus pusillus

Past climatic change as a driving force of marine diversification is still
largely unclear, particularly for Southern Hemisphere species. Here, we
present a case study using the brown fur seal, Arctocephalus
pusillus, and assess the geographical structure and demographic history
using mitochondrial and nuclear data. Results show the two previously
defined subspecies (one from Australia and the other from Southern Africa)
are phylogeographically distinct. Migration analyses based on nuclear data
suggest the absence of migrants among the two genetically close
assemblages. The demographic history of A. pusillus is characterized by a
glacial population expansion (~18 Kya) in the Southern African taxon,
which coincides with time estimates of population expansion of prey
species of seals. Approximate Bayesian Calculations support an eastward
dispersal event during the Last Glacial Maximum (LGM) when sea levels were
lower, followed by a postglacial divergence event, ~ 13 Kya. The
demographic history of the brown fur seal in the Southern Oceans provides
support that recent paleoclimatic changes could have facilitated
expansions in some marine species and that postglacial sea-level rise may
have acted as a dispersal barrier for species mostly confined to
continental shelves.