In the sprawling Siberian city of Novosibirsk, there's a research compound that's home to some of the world's newest and oddest dogs. They don't look odd, mind you, with their piebald coats, floppy ears, and wagging, upturned tails. They don't behave oddly, either. They wander up to the geneticists working there, yapping, sniffing, and licking their hands much as any domestic dog might do.
The reason they're remarkable is that they're not domestic dogs at all--they're silver foxes (known as red foxes in the United States), separated from Rin-Tin-Tin and Lassie by 12 million years of evolution. Prized for their fur, these wild and normally skittish animals reached their tame, doggielike state at the hands of Dmitry Belyaev, erstwhile director of the city's Institute of Cytology and Genetics. In a bid to create more manageable foxes for the fur industry, Belyaev began selectively breeding for tamer animals in 1958, transforming hostile, pointy-eared silver foxes into friendly, floppy-eared fox-dogs in a mere 20 generations.
That's how Belyaev got his version of a domesticated dog. But how did we first come by ours? We need only compare the number of chromosomes-- DNA bundles--in members of the canine family to see that our dogs aren't descended from foxes: silver foxes have just 36 chromosomes, whereas dogs have 78. Our dogs are derived from gray wolves, which not only also have 78 chromosomes but, more to the point, can still breed with dogs, making them members of the same species. Some 12,000 years ago, judging from archeological remains, these gray wolves loped into the lives of our hunter-gatherer forebears and then, over the millennia, gave rise to all the fantastic dog shapes and sizes that populate the planet today. In the United States alone an estimated 50 million dogs, from Akitas to weimaraners, now live in our homes, racking up an annual $6 billion in food bills and $4.5 billion in vet bills, and dumping a daily 20 million pounds of feces at our feet. Yet in many ways we're oddly hazy about the history of our closest animal companions. How did Canis lupus, the wolf, originate? How did he become Canis lupus familiaris, the domestic dog? And how did pugs and poodles, Lhasa apsos and Labradors come to be?
Recently the odds for cracking these mysteries have improved. Inspired by the Human Genome Project, a plan to map all the genes responsible for making a human, researchers have embarked on a similar project for the dog. One day they hope to pinpoint the genes that explain how our different breeds came about. Better still, from a canine point of view, some of this science might benefit the dogs themselves by weeding out an array of crippling genetic diseases we humans have encouraged by breeding weirder and wilder dog shapes.
Ironically, some of the earlier stages of dog evolution--before humans began manipulating the species--are becoming clearer than the later ones. All members of the dog family, including wolves, foxes, and domestic dogs, belong to the order Carnivora, a group whose hallmark is a super- specialized pair of teeth called the carnassials. Pull up your dog's lip, and you'll see them: the first molar on the lower jaw, and the last premolar on the upper jaw. They slide past each other like scissors, neatly shearing meat into chunks.
