Meeting Abstract

27.4  Wednesday, Jan. 5  Barking frogs and flowing genes: Molecular phylogenetics of the Craugastor augusti complex (Anura: Craugastoridae) STREICHER, J.W.*; FLORES-VILLELA, O.; SMITH, E.N.; Univ. of Texas, Arlington; UNAM, Mexico; Univ. of Texas, Arlington streicher@uta.edu

Polytypic species complexes are important models for defining the tempo and mode of speciation among closely related taxa. The Craugastor augusti complex is a group of species distributed from the southwestern United States southward to the Isthmus of Tehuantepec in Mexico. Previous comparisons of mitochondrial DNA (mtDNA) and breeding calls among populations have suggested two geographically isolated and genetically distinct lineages in the US. These data have been used to infer that the reciprocally isolated US populations originated from parallel northward radiations along moderate elevations of the Sierra Madre Occidental and the Sierra Madre Oriental. In the present study we test this hypothesis using an expanded molecular and geographic sampling of frogs. Our multilocus molecular dataset includes several mtDNA (12S) and nuclear DNA (Tyr, Rho, Rag-1, c-myc) genes (total of about 2800 base pairs). Additionally, we compiled 577 locality records from natural history collections in Mexico and the US to reexamine the geographic distribution of the complex. Preliminary examinations of these data indicate that the Craugastor augusti complex (1) exhibits several gene flow dynamics that are inconsistent with the hypothesis of independent northward dispersals and (2) is more widely distributed throughout the Mexican Plateau than previously estimated. In light of these findings we provide a revised biogeographic narrative and discuss relevant taxonomic and conservation implications.