MOLECULAR PHYLOGENETICS OF THE GENUS PIRANGA - IMPLICATIONS FOR BIOGEOGRAPHY AND THE EVOLUTION OF MORPHOLOGY AND BEHAVIOR

Species in the genus Piranga vary in degree of sexual dimorphism, plum age coloration, morphology, song, migratory patterns, and geographic d istribution. To study these aspects of Piranga biology in an evolution ary context, I constructed a phylogeny for this genus using cytochrome -b sequence data. Parsimony and maximum-likelihood analyses of DNA dat a reveal three possible phylogenies for species in this genus. All thr ee trees identify a clade containing P. rubriceps, I! leucoptera, and I! erythrorephala and a clade containing P. rubra, I! ludoviciana, I! olivacea, P.! bidentata, and I;! flava. The trees differ in the placem ent of P. roseogularis. Morphology, song, and plumage data did not agr ee with these phylogenies. Levels of sequence divergence and the phylo geny of haplotypes are consistent with the idea that I! flava as curre ntly described contains more than one evolutionary unit. Mapping the e volution of seasonal migration onto the DNA trees indicates that migra tion evolved once within piranga.