Sunday, October 31, 2010

More Than Man's Best Friend....

Archaeology Magazine - More than Man's Best Friend
More Than Man's Best Friend by Jarrett A. Lobell and Eric Powell Volume 63 Number 5, September/October 2010 Dogs have been an integral part of human culture for 15,000 years...sometimes in unexpected ways

All dogs descended from the gray wolf, the largest member of the Canidae family. (Copyright Staffan Widsrtrand/Nature Picture Library)
Today there are some 77 million dogs in the United States alone. But as late as 20,000 years ago, it's possible there wasn't a single animal on the planet that looked like today's beloved (at least in some cultures) Canis lupus familiaris. Just how and when the species first became recognizably "doggy" has preoccupied scientists since the theory of evolution first gained widespread acceptance in the 19th century. The idea that dogs were domesticated from jackals was long ago discarded in favor of the notion that dogs descend from the gray wolf, Canis lupus, the largest member of the Canidae family, which includes foxes and coyotes. While no scholars seriously dispute this basic fact of ancestry, biologists, archaeologists, and just about anyone interested in the history of dogs still debate when, where, and how gray wolves first evolved into the animal that is the ancestor of all dog breeds, from Neapolitan mastiffs to dachshunds. Were the first dogs domesticated in China, the Near East, or possibly Africa? Were they first bred for food, companionship, or their hunting abilities? The answers are important, since dogs were the first animals to be domesticated and likely played a critical role in the Neolithic revolution. Recently, biologists have entered the debate, and their genetic analyses raise new questions about when and where wolves first developed into what we today recognize as dogs.

It can be very difficult to distinguish between wolf and dog skeletons, especially early in the history of dogs, when they would have been much more similar to wolves than they are today. What are perhaps the earliest dog-like remains date to 31,700 years ago and were first excavated in the 19th century at Goyet Cave in Belgium. Paleontologist Mietje Germonpré of the Royal Belgian Institute of Natural Sciences recently led a team that studied a canid skull from the cave and concluded that it had a significantly shorter snout than wolves from the same period. This dog-like wolf could represent the first step toward domestication and would make the Paleolithic people we call the Aurignacians, better known as the first modern humans to occupy Europe, the world's first known dog fanciers. But the analysis is controversial, and there is a large gap between the age of the Goyet Cave "dog" and the next oldest skeletons that could plausibly be called dog-like, which date to 14,000 years ago in western Russia. Perhaps the Goyet Cave wolf represents an isolated instance of domestication and left no descendants. But based on finds of dog skeletons throughout the Old World, from China to Africa, we know that certainly by 10,000 years ago dogs were playing a critical role in the lives of humans all over the world, whether as sentries, ritual sacrifices, or sources of protein.

The archaeological record suggests dogs were domesticated in multiple places at different times, but in 2009, a team led by Peter Savolainen of the Royal Institute of Technology in Stockholm published an analysis of the mitochondrial DNA of some 1,500 dogs from across the Old World, which narrowed down the time and place of dog domestication to a few hundred years in China. "We found that dogs were first domesticated at a single event, sometime less than 16,300 years ago, south of the Yangtze River," says Savolainen, who posits that all dogs spring from a population of at least 51 female wolves, and were first bred over the course of several hundred years. "This is the same basic time and place as the origin of rice agriculture," he notes. "It's speculative, but it seems that dogs may have first originated among early farmers, or perhaps hunter-gatherers who were sedentary." But this year a team led by biologist Robert Wayne of the University of California, Los Angeles, showed that domesticated dog DNA overlaps most closely with that of Near Eastern wolves. Wayne and his colleagues suggest that dogs were first domesticated somewhere in the Middle East, then bred with other gray wolves as they spread across the globe, casting doubt on the idea that dogs were domesticated during a single event in a discrete location. Savolainen maintains that Wayne overemphasizes the role of the Near Eastern gray wolf, and that a more thorough sampling of wolves from China would support his team's theory of a single domestication event.

University of Victoria archaeozoologist Susan Crockford, who did not take part in either study, suspects that searching for a single moment when dogs were domesticated overlooks the fact that the process probably happened more than once. "We have evidence that there was a separate origin of North American dogs, distinct from a Middle Eastern origin," says Crockford. "This corroborates the idea of at least two 'birthplaces.' I think we need to think about dogs becoming dogs at different times in different places."

As for how dogs first came to be domesticated, Crockford, like many other scholars, thinks dogs descend from wolves that gathered near the camps of semi-sedentary hunter-gatherers, as well as around the first true settlements, to eat scraps. "The process was probably driven by the animals themselves," she says. "I don't think they were deliberately tamed; they basically domesticated themselves." Smaller wolves were probably more fearless and curious than larger, more dominant ones, and so the less aggressive, smaller wolves became more successful at living in close proximity to humans. "I think they also came to have a spiritual role," says Crockford. "Dog burials are firm evidence of that. Later, perhaps they became valued as sentries. I don't think hunting played a large role in the process initially. Their role as magical creatures was probably very important in the early days of the dog-human relationship."

Whatever the reasons behind their domestication, dogs have left their pawprints all over the archaeological record, sometimes literally, for thousands of years. Over the following pages, we explore not only the roles dogs played in past cultures throughout the world, but how ancient artists celebrated our oldest companions.

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