Systematics of the Rana catesbeiana species group and the phylogenetic informativeness of anuran vocalizations.

The Rana catesbeiana group, commonly known as bullfrogs, is a small group found in Eastern North America. It is diagnosed from other Rana by the presence of sexually dimorphic tympana, post-tympanic folds, over wintering tadpoles, submetacentric chromosome 9, and several base pair substitutions from the mitochondrial ND2 gene and three flanking tRNAs. The focus of this research is to test the informativeness of vocalizations in phylogenetic inference. I present evidence from morphology, life history, chromosomes, vocalizations, allozymes, ribosomal DNA, and mitochondrial DNA (mtDNA). A length incongruence test finds mtDNA to be incongruent with the other data used in hypothesis formation. Cladistic analysis of all the available data (TE) results in a hypothesis of (R. virgatipes (R. septentrionalis ((R. grylio, R. heckscheri)(R. catesbeiana (R. clamitans, R. okaloosae))))). MtDNA sequences support a hypothesis of (R. grylio (R. virgatipes (R. septentrionalis ((R. clamitans, R. okaloosae)(R. catesbeiana, R. heckscheri))))). The hypothesis resulting from the analysis of all the data except mtDNA is ((R. okaloosae, R. virgatipes)(R. septentrionalis (R. clamitans (R. catesbeiana(R. grylio, R. heckscheri))))). The placement of R. okaloosae is the major difference of these analyses. There are two call types in North American Rana, a chuckling call and a snoring call. The TE hypothesis indicates that the chuckling call is plesiomorphic and the snoring call has evolved independently in several Rana lineages. The performance of vocalization data in Rana is measured by comparing the character consistency and retention indices. By these measures, the vocalization data do not perform significantly worse than other types of data when measured against the TE hypothesis. When this analysis is expanded to other frog lineages, Kassina, Pseudacris, and Smilisca, the vocalization data show no significant differences from the other classes of characters used in hypothesis generation. All examinations of vocalization data suggest that these characters perform as well as other variables used in phylogenetic analysis.Ph.D.Biological SciencesMolecular biologyMorphologyZoologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/130162/2/9712123.pd