Historic demography and connectivity between Southern and Northern right whales

During the 18th and 19th century right whales (Eubalaena spp.) went through severe bottlenecks worldwide due to intensive whaling. Currently, there are three recognized right whale species: the North Atlantic right whale, E. glacialis, the southern right whale, E. australis (South Atlantic, Indo-Pacific), as well as the North Pacific right whale, E. japonica. As a result, all three species are classified as either endangered, or vulnerable. Right whales have been hypothesized to originate in the Southern Hemisphere from where they dispersed into theNorthern Hemisphere approx. 6 Mya, during a glacial maximum, to establish the new populations. Subsequent temperature increases formed an equatorial barrier to gene flow, leading to reproductive isolation and the present anti-Tropical distribution. In this study we employ genetic data to estimate past demographic changes as well as the degree of isolation between E. glacialis and E. australis through time. To this end we applied maximum likelihoodand Bayesian coalescent inference methods implemented in the software IMa2 and MIGRATION to mitochondrial control region nucleotide sequences and genotypes from nuclear microsatellite loci in 600 to 1200 individuals sampled from the extant populations of E. australis and E. glacialis