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作者 LeDuc, Richard Gene
書名 A systematic study of the delphinidae (Mammalia: Cetacea) using cytochrome B sequences
國際標準書號 9780591757842
book jacket
說明 104 p
附註 Source: Dissertation Abstracts International, Volume: 59-02, Section: B, page: 0558
Co-Chairs: William Perrin; Margo Haygood
Thesis (Ph.D.)--University of California, San Diego, 1997
Evolutionary relationships among delphinids are, at present, poorly understood. Previous systematic studies and published classifications were based on insufficient morphological data and/or outdated analytical methods. With the advent of genetic data and cladistic methodologies of phylogenetic inference, there are now opportunities for reexamining patterns of dolphin evolution
Using standard protocols, the entire cytochrome B gene was sequenced from all genera, all but two species of the delphinids and from four outgroup species. The data were analyzed using a variety of methods for inferring phylogenies, including weighted and unweighted parsimony, maximum likelihood, and neighbor-joining analyses. The results strongly indicate the need for a systematic revision of the family, and a provisional classification is presented
Among the well-supported findings that conflict with current classifications are the removal of Orcinus from the Globicephalinae, placement of Grampus within the Globicephalinae, the removal of all Lagenorhynchus spp. from the Delphininae, and the placement of Sousa in the Delphininae. Within the currently recognized genus Lagenorhynchus, L. albirostris and L. acutus are not closely related to each other or to the other species in that genus. L. acutus is therefore assigned to the genus Leucopleurus. The remaining species of Lagenorhynchus are closely related to Lissodelphis and Cephalorhynchus and are placed in the genus Sagmatias. These three genera constitute the revised subfamily Lissodelphinae
Within the Delphininae, a clade well-supported by the data includes the two species of Delphinus, Stenella clymene, S. frontalis, S. coeruleoalba, and the aduncus form of Tursiops truncatus. Accepting the monophyly of this group renders the genera Stenella and Tursiops polyphyletic. Apart from this finding, phylogenetic resolution within the Delphininae was poor. Taxonomic revision of this group awaits further study
Distant sister taxa relationships were found between Orcinus and Orcaella, and between Steno and Sotalia. Although support for these species pairs was low, they are provisionally placed in Orcininae and Stenoninae, respectively
The present results were compared to previous morphological studies, which suffered more from analytical shortcomings than from inadequate data
School code: 0033
Host Item Dissertation Abstracts International 59-02B
主題 Biology, Genetics
Biology, Oceanography
Biology, Zoology
Alt Author University of California, San Diego
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