Dog Sense by John Bradshaw Page A

wolf populations of Europe, this information gives us little insight into the behavior of the first domestic dogs. Modern wolves are only very distantly related to the domestic dog, and they have been under intensive selection pressure, especially over the past few hundred years, from those who wished to exterminate them. It is therefore unsurprising that today’s wolves are very difficult to socialize, and that tame wolves tend to remain unpredictable and potentially aggressive toward people throughout theirlives. By persecuting wolves, we have selected those individuals that are naturally wary of us; it is therefore very difficult to derive any knowledge about early dogs from what we know about contemporary wolves. Moreover, we cannot even replicate domestication, by taking wolves out of the wild and selectively breeding them to become more like dogs. Since the wolves that were the direct ancestor of domestic dogs are, in their original form, extinct, that would be impossible.
    One recent modification of a canid is widely held to provide pointers as to how wolves might have changed into dogs. This is the silver fox, a color variety of the wild red fox that is bred in fur-farms. Silver foxes are usually kept in cages and are barely tame, let alone domesticated, but in the 1950s a group of Russian scientists began to breed them selectively, using only the tamest individuals in each generation. 8 At first, few of the foxes could be handled, even by a person offering a tasty food treat. After a few generations of breeding only from individuals that would tolerate handling, however, some individuals emerged that would actively seek contact from people. Indeed, after thirty-five generations, most of the foxes were behaving in a remarkably dog-like way—wagging their tails, whimpering to attract attention, sniffing and licking their handlers’ hands and faces. Some were even taken home as pets by the staff, who reported that these animals could be as obedient and loyal as domestic dogs. The geneticists’ objective of producing a fox that was easier to handle seemed to have improved its welfare too. Freed from the relentless fear and anxiety of having to encounter an alien species (us!) every day of their lives, the new “tame” farm-foxes exhibit levels of stress hormones four times lower than those in the original “wild” version. A similar reduction in reactivity, and susceptibility to stress, is evident when dogs are compared with wolves—a reduction traceable to changes in the hypothalamus, a part of the brain that is, among several functions, concerned with emotional reactivity. Such changes are probably a direct consequence of selection for tameness, so in this respect the tame farm-foxes may well be similar to the wolves that adapted to living near, and scavenging from, human settlements.
    The most interesting finding of the Siberian fox experiment was that the farm-foxes became easier to tame because the period before they became frightened of new experiences was effectively lengthened.Most young mammals go through a period of their lives in which they are naturally inquisitive and trusting. And it’s usually during this stage that they’re still being looked after by their parents, who are on hand to make sure that these characteristics don’t get them into trouble. As they get older and more independent, the offspring become much more suspicious of anything unusual and much more likely to run away after an initial inspection. In the farm-foxes, selection for tameness corresponded with an extension of this “trusting” phase, which ends when wild foxes are about six weeks old but lasts for about nine weeks in the “tame” variety. That extra three weeks is enough to allow regular handling to take effect, producing a fox that trusts, rather than fears, the people who look after it.
    Another finding of the Siberian experiment has been used to posit the effect