Combined analysis of fourteen nuclear genes refines the Ursidae phylogeny

To definitively solve the last the ambiguities concerning the evolutionary history of Ursidae, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with those of four other recently published nuclear markers, we provide new insights into the phylogenetic relationships of the Ursidae family members. The hypothesis that the giant panda was the first species to diverge among ursids is definitively confirmed and the branching order within the Ursus genus is clarified for the first time. Moreover, these analyses indicate that the American and the Asiatic black bears do not cluster as sister taxa, as had been previously hypothesised. Sun and sloth bears undoubtedly appear as the most basal ursine species but uncertainties about their exact relationships remain.