Phylogeny

gray wolf[b]

Perpetual Wolf Cubs

For a discussion of how play behavior evolved in mammals and its current time adaptive value, please visit Adaptive Value.

Bare Bones Beginnings
Using bones found at archaological digs as the dating method, domestic dogs evolved from wolves in the range of 10-14 thousand yeards ago. Before DNA evidence became a part of the picture, it was impossible for scientists to prove definitively that dogs were the descendents of wolves. Certainly they were members of the Canid family; however, their ancestoral species were less than clear. Darwin and Lorenz are two of the larger names who proposed different theories about the domestication of dogs. Darwin pointed to the interspecial breeding capacities of wolves, coyotes, and jackals as proof that we could never fully discover the origin species. Lorenz suggested that different dog breeds might come from different ancestors (some from wolves, others from jackals). [3]

Genetic Input
Along came Vila et al. In 1997, they reported in Science of the extensive mitochondrial DNA testing they performed on members of the Canid family. Vila et al sequenced a portion of the mitochondrial DNA of 140 dogs, 162 wolves, 5 coyotes, and 8 jackals. Within the domestic dog species,between breeds, haplotypes differed on average by 5 base pairs substitutions, ranging up to a maximum of 12 substitutions. Surprisingly, the difference in DNA sequence between domestic dogs and wolves also maxed out at 12 substitutions. Between dogs and either jackals or coyotes, there was a minimum of 20 substitutions in difference. These findings strongly support the wolves-as-ancestors hypothesis, and have been supported by less extensive nuclear DNA marker studies. [8]

Wolf Play = Dog Play?
Can we see the wolf ancestry in the play behavior of domestic dogs? Beckoff 's interspecial analysis of play behavior in young canids affirms this whole-heartedly. He states that, "the social development of the wolf in very early life appears not to be very different from that of the beagle," and continuously points to the extensiveness of their similarities over any other two-group comparisons.He also writes that the play behaviors are a reasonable side effect of artificial selection by humans on the beagles, as the hounds are hunting dogs who are bred to coordinate their actions in highly social packs. [3]

A phylogenetic tree of the Canid family, created from genetic analyses done in 2001. Note the close relationship of the domestic dog and the gray wolf. [c]

phylogenetic tree