Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): implications for the conservation of frogs and rivers

Abstract

Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b and ND2 fragments for 77 individuals from 34 localities using phylogenetic and population genetic analyses. We constructed gene trees using maximum likelihood and Bayesian inference, and quantified genetic variance (using AMOVA and partial Mantel tests) within and among hydrologic regions and river basins. Several moderately supported, geographically-cohesive mtDNA clades were recovered for R. boylii. While genetic variation was low among populations in the largest, most inclusive clade, samples from localities at the edges of the geographic range demonstrated substantial genetic divergence from each other and from more central populations. Hydrologic regions and river basins, which represent likely dispersal corridors for R. boylii, accounted for significant levels of genetic variation. These results suggest that both rivers and larger hydrologic and geographic regions should be used in conservation planning for R. boylii.

Crossing the uncrossable: novel trans‐valley biogeographic patterns revealed in the genetic history of low‐dispersal mygalomorph spiders (Antrodiaetidae,Antrodiaetus) from California

“…In Rana boylii frogs, a mitochondrial ‘central coast’ clade includes animals from the south Coast Ranges and the northern Sierran foothills (Yuba county, Lind et al . ). In Promyrmekiaphila trapdoor spiders, populations from the eastern edge of the Diablo Range are related by mitochondrial evidence to animals from the northern Sacramento Valley, rather than to geographically adjacent populations (Stockman & Bond ).…”

Rapid extirpation of a North American frog coincides with an increase in fungal pathogen prevalence: Historical analysis and implications for reintroduction

“…R . boylii is more phylogenetically distinct at the edges of its range than at the core—the most distinct and divergent lineages occur at the southern portion of its range (Lind et al., )—suggesting that the southern California populations may have differed in their susceptibility to Bd and subsequent extirpation. Differential outcomes in Bd susceptibility have been observed in the field (Briggs et al., ), and under identical conditions in the laboratory (Searle et al., ) (C. Davidson, unpublished data).…”

Amphibian molecular ecology and how it has informed conservation

“…The locations of past refugia as inferred through phylogeographic studies can also be used to verify that a species distribution model performs well in hindcasting (Scoble & Lowe 2010), making it more believable for forecasting. Phylogeographic studies can also be used to understand how diversity is partitioned in modern times (Canestrelli et al 2008;Lind et al 2011;Lawson 2013) and how modern conservation challenges may be a result of historical landscape processes (Dufresnes et al 2013). In a similar vein, studies of ancient DNA allow us to more explicitly measure how genetic diversity has changed through time (McMenamin & Hadly 2012).…”