Fox Domestication and Genetics of Complex Behaviors

Domestication as a special form of evolution offers valuable insight into how genomic variation contributes to complex differences in behavioral and morphological phenotypes. The genetics-centered view of the domestication is supported by experimental selection of farm-bred foxes (Vulpes vulpes) that begun at the Russian Institute of Cytology and Genetics in the 1950s. Selection of foxes, separately, for tame and for aggressive behavior, has yielded two strains with markedly different, genetically determined behavioral phenotypes. Tame-strain foxes communicate with humans in a positive manner and eager to establish human contact. Foxes from the aggressive strain are aggressive to humans and difficult to handle. Although selected solely for behavior, changes in physiology, morphology, and appearance with significant parallels to characteristics of the domestic dog, were observed in tame-strain foxes. These fox strains provide a rich resource for investigating the genetics of complex social behaviors. Although the focus of our work is on the genetics of domestication in the silver fox, there is a broader context. In particular, one expectation of the silver fox research is that it will be synergistic with studies in other species, including humans, to yield a more comprehensive understanding of the molecular mechanisms and evolution of a wider range of social interactive behaviors.