Perception and history: Molecular phylogeny of a diverse group of neotropical frogs, the 30-chromosome Hyla (Anura : Hylidae)

We used 16S rRNA, 12S rRNA, and cytochrome-b sequence to investigate the hi story of the "30-chromosome" Hyla, a diverse assemblage of neotropical tree frogs. Three aspects of these frogs were examined: (1) phylogenetic relatio nships among constituent species groups, among the species of one of these groups (Hyla leucophyllata group), and among populations of HyLa leucophyll ata; (2) the apparent age of cladogenetic events; and (3) the phylogeograph y of H. leucophyllata. Mixed success in resolving the phylogeny is not beca use of a lack of character variation; levels of genetic divergence are high and suggest pre-Pleistocene diversification, even among populations. Close temporal proximity of ancient cladogenetic events might make resolution of the topology difficult using any character set. At the population level, c urrent geographic proximity is a poor predictor of phylogenetic affinity. A long history of dispersal and colonization may complicate, or even preclud e, the accurate recovery of the history of this species in the Amazon Basin . It remains to be seen whether the patterns found here will prove common a mong neotropical frogs. (C) 2001 Academic Press.