Molecular insights into the evolution of the family Bovidae: A nuclear DNAperspective

The evolutionary history of the family Bovidae remains controversial despit e past comprehensive morphological and genetic investigations, in an effort to resolve some of the systematic uncertainties within the group, a combin ed molecular phylogeny was constructed based on four independent nuclear DN A markers (2,573 characters) and three mitochondrial DNA genes (1,690 chara cters) for 34 bovid taxa representing all seven of the currently recognized bovid subfamilies. The nuclear DNA fragments were analyzed separately and in combination after partition homogeneity tests were performed. Thew was n o significant rate heterogeneity among lineages, and retention index values indicated the general absence of homoplasty in the nuclear DNA data. The c onservative nuclear DNA data were remarkably effective in resolving associa tions among bovid subfamilies, which had a rapid radiation dating back to a pproximately 23 MYA. All analyses supported the monophyly of the Bovinae (c ow, nilgai, and kudu clade) as a sister lineage to: the remaining bovid sub families, and the data convincingly suggest that the subfamilies Alcelaphin ae (hartebeest, tsessebe, and wildebeest group) and Hippotraginae (roan, sa ble, and gemsbok clade) share a close evolutionary relationship and togethe r form a sister clade to the more primitive Caprinae (represented by sheep, goat, and muskox). The problematic Reduncinae (waterbuck, reedbuck) seem t o be the earliest-diverging group of the Caprinae/Alcelaphinae/Hippotragina e clade, whereas the Antilopinae (gazelle and dwarf antelope clade) were al ways. polyphyletic. The sequence data suggest that the initial diversificat ion of the Bovidae took place in Eurasia and that lineages such as the Ceph alophinae and other enigmatic taxa (impala, suni, and klipspringer) most Li kely originated, more or less contemporaneously, in Africa.