Worldwide phylogeny of three-spined sticklebacks

Stickleback fishes in the family Gasterosteidae have become model organisms in ecology and evolutionary biology. However, even in the case of the most widely studied species in this family – the three-spined stickleback (Gasterosteus aculeatus) – the worldwide phylogenetic relationships and colonization history of the different populations and lineages remain poorly resolved. Using a large collection of samples covering most parts of the species distribution range, we subjected thousands of single nucleotide polymorphisms to coalescent analyses in order to reconstruct a robust worldwide phylogeny of extant G. aculeatus populations, as well their ancestral geographic distributions using Statistical-Dispersal Vicariance and Bayesian Binary MCMC analyses. The results suggest that contemporary populations originated from the Pacific Ocean in the late Pleistocene, and the Atlantic was colonized through the Arctic Ocean by a lineage that diverged from Pacific sticklebacks ca 44.6 Kya. This li...