| Amphibians exhibit conservative morphological evolution, and molecular genetic tools in systematic studies have been effective at revealing morphologically 'cryptic' species within taxa that were previously considered to be a single species.; Molecular and morphological data were used to identify evolutionary lineages of the Southeast Asian frog genus Odorrana and to estimate their phylogenetic relationships. Odorrana was resolved as a monophyletic group within the family Ranidae. Remarkable morphological convergences were found among evolutionarily unrelated, but ecologically similar, Southeast Asian ranids that live along swift, forested streams. Mitochondrial DNA sequences from frogs that morphologically resembled O. livida revealed two deeply divergent, sympatric lineages at multiple localities, and phylogenetic analyses showed that sympatric lineages were usually not each other's closest relatives. Most of the mitochondrial lineages were also diagnosed by at least one morphological character, and these were hypothesized to be distinct species. Historic DNA obtained from the neotype specimen showed that true O. livida actually occupies only a small portion of its published geographic range. The traditional concept of O. livida does not represent a monophyletic group within the genus Odorrana. Nuclear intron sequence data recovered most major mitochondrial clades. Most lineages of Odorrana were obtained in sympatry with at least one other Odorrana. Three lineages of Odorrana were formally described as new species to science. Unpigmented eggs independently appeared twice, and gular pouches were independently lost three times, during the evolution of Odorrana.; Two additional studies were undertaken to examine the prevalence of genetically divergent but morphologically cryptic lineages in widespread, forest-dwelling Southeast Asian frogs. As with O. livida, two deeply divergent, sympatric mitochondrial lineages were found at multiple localities in frogs that morphologically resembled Rana chalconota. Sympatric cryptic lineages were not found in frogs of the Rhacophorus verrucosus group, but patterns of genetic variation corresponded poorly with currently recognized species boundaries.; The results strongly suggest that amphibian species diversity in Southeast Asia remains significantly underestimated. Single, widespread species actually represent multiple species having smaller ranges, many of which occur in sympatry. These findings have important implications for the fields of biodiversity conservation, historical biogeography, and community ecology. |
