Phylogenetic relationships of peccaries based on mitochondrial cytochrome B DNA sequences

We compared 1,047 base pairs (bp) of the mitochondrial cytochrome b gene from the three species of extant peccaries - the collared peccary (Pecari tajacu), the white-lipped peccary (Tayassu pecari), and the Chacoan peccary (Catagonus wagneri); three suids - domestic pig (Sus scrofa), warthog (Phacochoerus aethiopicus), and babirusa (Babyrousa babyrussa) - were used as outgroups. Phylogenetic analyses using parsimony and maximum likelihood resulted in trees that placed the Chacoan peccary and the white-lipped peccary in a clade separate from the collared peccary. This relationship remains tentative, however, as tree topologies supporting alternate hypotheses were not significantly worse than the maximum likelihood tree. Estimated times since divergence based on cytochrome b suggest that Tayassu and Catagonus diverged in the late Pliocene, perhaps concommitant with the invasion of South America by tayassuids. The divergence of the Pecari lineage from that of the other two species was estimated to be at 3.4-7.4 × 10⁶ years ago, supporting the hypothesis that these two clades diverged in North America before either clade colonized South America. Our results support the classification of extant species of peccaries into three genera.