Cytochrome b phylogeny of the family bovidae: Resolution within the Alcelaphini, Antilopini, Neotragini, and Tragelaphini

The family Bovidae is characterized by an incomplete fossil record for the period during which most bovid subfamilies emerged. This, coupled to extens ive morphological convergence among species, has given rise to inconsistenc ies in taxonomic treatments, especially at the tribal and subfamilial level s. In an attempt to clarify some of these issues we analyzed the complete m tDNA cytochrome b gene (1140 bp) from 38 species/subspecies representing at least nine tribes and six subfamilies. Specific emphasis was placed on the evolution of the Alcelaphini (hartebeest and wildebeest), the Tragelaphini (kudu, eland, and close allies), the Antilopini (gazelles), and the Neotra gini (dwarf antelope). Saturation plots for the codon positions revealed di fferences between bovid tribes and this allowed for the exclusion of transi tional substitutions that were characterized by multiple hits. There was no significant rate heterogeneity between taxa. By calibrating genetic distan ce against the fossil record, a transversion-based sequence divergence of 0 .22% (+/-0.015%) per million years is proposed for cytochrome b clock calib rations in the Bovidae. All evidence suggests that the Alcelaphini form a m onophyletic group; there was no support for the recognition of the Lichtens tein's hartebeest in a separate genus (Sigmoceros), and the acceptance of t he previously suggested Alcelaphus is recommended for this species. High bo otstrap support was found for a sister taxon relationship between Alcelaphu s and Damaliscus, a finding which is in good agreement with allozyme and mo rphological studies. In the case of the Tragelaphini, the molecular data su ggest the inclusion of Taurotragus in the genus Tragelaphus, and no genetic support was found for the generic status of Boocercus. Although associatio ns within the Antilopinae (comprising the tribes Neotragini and Antilopini) could not be unequivocally resolved, there was nonetheless convincing evid ence of non-monophyly for the tribe Neotragini, with the Suni antelope (Neo tragus moschatus) grouping as a sister taxon to the Impala (Aepyceros melam pus, tribe indeterminate, sensu Gentry, 1992) and the Klipspringer (Oreotra gus oreotragus) falling within the duiker antelope tribe (Cephalophini). (C ) 1999 Academic Press.