Data from: Geographic and temporal dynamics of a global radiation and diversification in the killer whale

Global climate change during the Late Pleistocene periodically encroached
and then released habitat during the glacial cycles, causing range
expansions and contractions in some species. These dynamics have played a
major role in geographic radiations, diversification and speciation. We
investigate these dynamics in the most widely distributed of marine
mammals, the killer whale (Orcinus orca), using a global data set of over
450 samples. This marine top predator inhabits coastal and pelagic
ecosystems ranging from the ice edge to the tropics, often exhibiting
ecological, behavioural and morphological variation suggestive of local
adaptation accompanied by reproductive isolation. Results suggest a rapid
global radiation occurred over the last 350 000 years. Based on habitat
models, we estimated there was only a 15% global contraction of core
suitable habitat during the last glacial maximum, and the resources
appeared to sustain a constant global effective female population size
throughout the Late Pleistocene. Reconstruction of the ancestral
phylogeography highlighted the high mobility of this species, identifying
22 strongly supported long-range dispersal events including interoceanic
and interhemispheric movement. Despite this propensity for geographic
dispersal, the increased sampling of this study uncovered very few
potential examples of ancestral dispersal among ecotypes. Concordance of
nuclear and mitochondrial data further confirms genetic cohesiveness, with
little or no current gene flow among sympatric ecotypes. Taken as a whole,
our data suggest that the glacial cycles influenced local populations in
different ways, with no clear global pattern, but with secondary contact
among lineages following long-range dispersal as a potential mechanism
driving ecological diversification.