One of the most extensive surveys of the earliest known dog burials suggests humans domesticated canines much later than other studies show. The survey, which suggests domestication occurred between 13,000 and 17,000 years ago, counters some earlier theories based on gene changes that distinguish dogs from their wild wolf counterparts.
     A few of those theories held that domestication occurred anywhere between 40,000 and 135,000 years ago, much earlier than the new study suggests. The new study, published in the February issue of the Journal of Archaeological Science, suggests that the bond between humans and dogs coincides with canine burials.
     The earliest known morphological evidence of what was probabably dog remains dates to around 17,000 years ago in central Russia. But the practice of burying dogs appears to have begun between 14,000 and 15,000 years ago. Burying dogs then became more common around 12,000 years ago. "This was a time of major population expansion, starting with, for our purposes, colonisation for the first time of eastern Eurasia and finally on into the New World," says author Darcy Morey, an assistant professor in archaeology from the University of Kansas.
     The burials reveal our evolving relationship with dogs. Often dog skeletons lay alongside human ones. In one 7000-year-old Swedish grave, archaeologists found the remains of a dog stretched out on the legs of a deceased man, as though the man hoped to hold and pet his canine friend for eternity. The dog's neck was broken, indicating that it had been killed when its owner died. Dogs buried without humans in North and Central America still show a loving touch and possibly a ritualised internment. A grave found in what is now Rhode Island, for example, contains a prehistoric dog that was arranged to lie on its left side with its front paw under its head.
     The age and condition of the dogs when they died also reveal domestication and the bond with humans, according to Morey. He describes a Middle Archaic burial dating from 6700 to 7180 years ago that was found in what is now Tennessee. The male dog discovered in the grave was 'unusually old'.  Its skeleton indicates the animal suffered from traumatic injuries, arthritis, a persistent infection, and broken bones, some of which had healed, and some that had not. "The pathological condition of this individual suggests that the owner insured the safety and well-being of the individual throughout its life since it is doubtful that, given all the traumatic and age degenerative manifestations, the dog could have survived in the absence of care," Morey explains.
     Christyann Darwent, an assistant professor of anthropology at the University of California at Davis, says she agrees with Morey's time window for dog domestication. "Dogs and humans could have been hanging out together long before 17,000 years ago, but domestication means we were manipulating their breeding, and that probably didn't happen until more recently," she says. "The burials represent some of the best evidence we have for the strong social ties that exist between dogs and humans."

Source: Discovery News (1 February 2006)