The History of Farm Foxes Undermines the Animal Domestication Syndrome.

The Russian Farm-Fox Experiment is the best known experimental study in animal domestication. By subjecting a population of foxes to selection for tameness alone, Dimitry Belyaev generated foxes that possessed a suite of characteristics that mimicked those found across domesticated species. This 'domestication syndrome' has been a central focus of research into the biological pathways modified during domestication. Here, we chart the origins of Belyaev's foxes in eastern Canada and critically assess the appearance of domestication syndrome traits across animal domesticates. Our results suggest that both the conclusions of the Farm-Fox Experiment and the ubiquity of domestication syndrome have been overstated. To understand the process of domestication requires a more comprehensive approach focused on essential adaptations to human-modified environments.

Variation in reproductive traits of members of the genus Canis with special attention to the domestic dog (Canis familiaris).

We compare differences in the reproductive strategies of "free-living" dogs with their wild relatives in the genus Canis, of which the dog is a very recently evolved member. The members of this genus display a greater range of parental motor patterns than generally seen in other species of Carnivora, including pair-bonding and extended parental care; parents regurgitate to offspring and provision them with food for months to as long as a year. But the domestic dog does not routinely display these genus-typical behaviors. While this has generally been assumed to be a result of direct human intervention, humans have little reproductive control over the vast majority of domestic dogs. We analyze the low frequency of display of genus-typical behaviors and postulate that the dog's reproductive behaviors are an adaptation to permanent human settlement and the waste resources associated with it. Adaptation to this environment has decreased seasonality, increased the fecundity of unrestrained dogs and reduced the need for prolonged parental care. The consequences of greater fecundity and reduced parental care are compared to the reproductive behavior of other species of the genus.

Barking and mobbing.

Barking is most often associated with the domestic dog Canis familiaris, but it is a common mammalian and avian vocalization. Like any vocalization, the acoustic character of the bark is likely to be a product of adaptation as well as an expression of the signaler's internal motivational state. While most authors recognize that the bark is a distinct signal type, no consistent description of its acoustic definition or function is apparent. The bark exhibits considerable variability in its acoustic form and occurs in a wide range of behavioral contexts, particularly in dogs. This has led some authors to suggest that dog barking might be a form of referential signaling, or an adaptation for heightened capability to communicate with humans. In this paper we propose a general 'canonical' acoustic description of the bark. Surveying relevant literature on dogs, wild canids, other mammals and birds, we explore an alternative functional hypothesis, first suggested by [Morton, E.S., 1977. On the occurrence and significance of motivation-structural rules in some bird and mammal sounds. Am. Nat. 111, 855-869] and consistent with his motivational-structural rules theory: that barking in many animals, including the domestic dog, is associated with mobbing behavior and the motivational states that accompany mobbing.