Genetic structure across broad spatial and temporal scales: Rocky Mountain tailed frogs (Ascaphus montanus; Anura: Ascaphidae) in the inland temperate rainforest

Contemporary and historical processes interact to structure genetic variation, however discerning between these can be difficult. Here, we analyze range-wide variation at 13 microsatellite loci in 2098 Rocky Mountain tailed frogs, Ascaphus montanus, collected from 117 streams across the species distribution in the Inland Northwest (INW) and interpret that variation in light of historical phylogeography, contemporary landscape genetics, and the reconstructed paleodistribution of the species. Further, we project species distribution models (SDMs) to predict future changes in the range as a function of changing climate. Genetic structure has a strong spatial signature that is precisely congruent with a deep (~1.8 MY) phylogeographic split in mtDNA when we partition populations into 2 clusters (K = 2), and is congruent with refugia areas inferred from our paleorange reconstructions. There is a hierarchical pattern of geographic structure as we permit additional clusters, with populations cl...