title: Phylogenetic relationships among the true porpoises (Cetacea:Phocoenidae).
abstract: Portions of the cytochrome b gene and control region of the mitochondrial DNA molecule were sequenced to investigate systematic relationships among the six extant species of true porpoises, (Cetacea: Phocoenidae). Phylogenetic analyses of mitochondrial cytochrome b sequences support a close relationship between Burmeister's porpoise, Phocoena spinipinnis, and the vaquita, Phocoena sinus, and the association of these two species with the spectacled porpoise, Australophocaena dioptrica. The latter result is not in concordance with a recent morphological reclassification which groups A. dioptrica with Dall's porpoise, Phocoenoides dalli, in the subfamily Phocoenoidinae. The molecular analysis found no support for this grouping. A. dioptrica was originally described as a member of the genus Phocoena, and our results support returning it to that genus at this time. Finally, the data suggest that the tropical species Neophocaena phocaenoides, the finless porpoise, may represent the most basal member of the family. The control region sequences corroborated the relationships among the closely related taxa P. sinus, P. spinipinnis, and A. dioptrica, but were unable to resolve the deeper branches of the tree, probably as a result of a high level of saturation of these sequences.
authors: Scripps Institution of Oceanography, Marine Biology Research Division, University of California, San Diego 92093-0202, USA. per@christa.unh.edu
authors: P E
authors: PE
authors: Rosel
authors: M G
authors: MG
authors: Haygood
authors: W F
authors: WF
authors: Perrin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D003573:Cytochrome b Group / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004289:Dolphins / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D003573:Cytochrome b Group; D017931:DNA Primers; D004272:DNA, Mitochondrial