Some facts about the evolutionary relationships of charismatic dholes
Canids form one of the most prominent families of carnivores, with 36 interesting taxa in 13 genera that occur throughout most of the world. As a family, canids occupy every continent except Antarctica. Foxes, dholes, dingoes, wolves, jackals, coyotes and various dogs comprise the family.
Within the canid family the dhole is something of an enigma and it is classified in a genus of its own - Cuon. All dholes belongs to the species Cuon alpinus, which includes nine extant subspecies.
The genus Cuon is post-Pleistocene in origin. In 1945 Simpson placed the dhole in the subfamily Simocyoninae of the family Canidae, together with the African wild dog (Lycaon pictus) and the bush dog (Speothos venaticus) of South America on the basis of shared anatomical features, most notably the reduction of the role of the crushing post-carnassial molars. Many have questioned Simpson’s classification arguing that similarities in dentition are due to convergent evolution because of a highly predatory diet.
Currently, evolutionary relationships within the family Canidae, reconstructed using comparative karyology, allozyme electrophoresis, mtDNA protein coding sequence data, and super tree method, as well as the relationships at the genus level studied with mtDNA, shows that the living Canidae is divided into five distinct groupings. These include the wolf-like canids, which consists of the coyote, grey wolf, Ethiopian wolf, jackals, dhole and African wild dog. This clade is associated with a group containing bush dog and maned wolf in some trees and, further, this larger grouping is associated with the South American foxes. The red fox group is a fourth independent clade, and finally, three lineages have long distinct evolutionary histories and are survived today by the raccoon dog, bat-eared fox and island and gray fox.
The wolf genus Canis is a monophyletic group that also includes the dhole. Basal to Canis and Cuon are the African wild dog and a clade consisting of two South American canids, the bush dog (Speothos venaticus) and the maned wolf (Chrysocyon brachyurus). Consequently, although the African wild dog preys on large game as does the grey wolf and dhole, it is not closely related to either species but is sister to the clade containing these species. This phylogeny implies that the trenchant-heeled carnassial now found only in Speothos, Cuon and Lycaon, evolved at least twice or was primitive and lost in other wolf-like canids and the maned wolf.
In summary, dholes are part of a clade of wolf-like canids within which is related more closely to the extant jackals than to wolves.
Photo: a pair of Indian dholes in wild, Cuon alpinus dukhunensis, from Maharastra National Park, Central India | ©Sandeep Dutta