Isolation by distance and post‐glacial range expansion in the rough‐skinned newt, Taricha granulosa

Abstract

Allozymes and mitochondrial DNA sequences were used to examine the phylogeographical history of the rough-skinned newt, Taricha granulosa, in western North America. Nineteen populations were analysed for allozyme variation at 45 loci, and 23 populations were analysed for cytochrome b sequence variation. Both data sets agree that populations in the southern part of the range are characterized by isolation by distance, whereas northern populations fit the expectations of a recent range expansion. However, the northern limit of isolation by distance (and the southern limit of range expansion) is located in Oregon State by the mtDNA data, and in Washington State by the allozyme data. Nevertheless, both data sets are consistent with the known Pleistocene history of western North America, with phylogenetically basal populations in central and northern California, and a recent range expansion in the north following the retreat of the Cordilleran ice sheet 10 000 years ago. Additionally, a population in Idaho, previously considered introduced from central California based on morphometric analyses, possesses a distinct mtDNA haplotype, suggesting it could be native. The relevance of these results for Pacific Northwest biogeography is discussed.

Molecular phylogeography of endangered sharp-snouted pitviper (Deinagkistrodon acutus; Reptilia, Viperidae) in Mainland China

“…Taking no account of anthropogenic influence, isolation by distance or/and geography might play important role(s) in the evolutionary history of amphibians and reptiles with limited vagility (e.g., Kuchta and Tan, 2005). In the present study, isolation-by-distance appears to be a factor involved in the population genetic structuring of D. acutus.…”

Cryptic species within the cosmopolitan desiccation-tolerant moss Grimmia laevigata

“…Studies of multiple taxa within the region have shown evidence of phylogeographic structure (e.g., refs. [33][34][35]. Moreover, multiple studies have shown higher levels of phylogeographic differentiation in California than in the Pacific Northwest, where populations of many species became established only after the retreat of Pleistocene glaciers (26,36,37).…”

A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata)

“…Our phylogenetic placement of Notophthalmus and Taricha is congruent with the allozymebased phylogeny of Hayashi and Matsui (1989). Relationships among species within Notophthalmus and Taricha have not previously been explored, although a number of studies have addressed phylogeography within individual species (Gabor and Nice, 2004;Kuchta and Tan, 2005;Reilly, 1990;Tan and Wake, 1995). Within Notophthalmus, Bayesian analysis strongly groups N. perstriatus and N. viridescens as sister species (Fig.…”