Phylogenetic position of Mexican jackrabbits within the genus Lepus (Mammalia: Lagomorpha): a molecular perspective

Although phylogenetic affinities of Mexican jackrabbits within the genus Lepus have been evaluated for a few species, no study has included all 5 species occurring in Mexico. In this study we assess the phylogenetic position of the Mexican species relative to other forms within the genus and evaluate evolutionary affinities among the Mexican forms. To do so, we analyzed 57 complete cytochrome b sequences belonging to the 5 Mexican jackrabbits and 18 species of Leptis distributed across Asia, Africa, Europe and America. We performed phylogenetic tree reconstruction with the neighbor-joining, maximum parsimony and maximum likelihood approaches. We also used a minimum spanning network to evaluate relationships among Mexican species. We found 5 main phylogenetic groups within Lepus, 4 of which corresponded to geographically well defined lineages. One group included L. americanus, 3 others corresponded to Mexican, African and European species, respectively. A fifth group included Asiatic, European and American forms. Our results suggest that Mexican species constitute a monophyletic entity that evolved independently of the other American species of Leptis. Within the Mexican forms, 2 main clades are apparent; 1 that includes L. alleni, L. callous, and L. flavigularis, previously referred to as the white-sided jackrabbits, and a second one that groups together L. californicus and L. insularis, although L. californicus is a paraphyletic relative of L. insularis.