Phylogeography of the Blue-spotted Salamander, Ambystoma laterale (Caudata: Ambystomatidae)

—The blue-spotted salamander (Ambystoma laterale) has the northern-most distribution of any North American salamander and primarily occurs in areas that were once covered by the southern Laurentide Ice Sheet during the last glacial maximum. We examine the phylogeography of this primary post-glacial invader of northern North America. Mitochondrial DNA sequence data indicate a clade comprised of populations from the western portion of the species’ range. Data from six nuclear DNA microsatellite loci support this finding. Taken together, the genetic data suggest rejection of the existing hypothesis of a single, western glacial refugium for this species in favor of two alternative hypotheses.