PHYLOGENETIC-RELATIONSHIPS WITHIN CANIFORM CARNIVORES BASED ON ANALYSES OF THE MITOCHONDRIAL 12S RIBOSOMAL-RNA GENE

The complete 12S rRNA gene of 32 carnivore species, including four fel iforms and 28 caniforms, was sequenced. The sequences were aligned on the basis of their secondary structures and used in phylogenetic analy ses that addressed several evolutionary relationships within the Canif ormia. The analyses showed an unresolved polytomy of the basic canifor m clades; pinnipeds, mustelids, procyonids, skunks, Ailurus (lesser pa nda), ursids, and canids. The polytomy indicates a major diversificati on of caniforms during a relatively short period of time. The lesser p anda was distinct from other caniforms, suggesting its inclusion in a monotypic family, Ailuridae. The giant panda and the bears were joined on the same branch. The skunks are traditionally included in the fami ly Mustelidae. The present analysis, however, showed a less close mole cular relationship between the skunks and the remaining Mustelidae (se nsu stricto) than between Mustelidae (sensu stricto) and Procyonidae, making Mustelidae (sensu late) paraphyletic. The results suggest that the skunks should be included in a separate family, Mephitidae. Within the Pinnipedia, the grouping of walrus, sea lions, and fur seals was strongly supported. Analyses of a combined set of 12S rRNA and cytochr ome b data were generally consistent with the findings based on each g ene.