Dogs, Wolves Share Gene Pool

That wiggly puppy pestering its owner for a chew toy may not look much like its wolf ancestors, but genetic research on our canine companions shows many have more in common with White Fang than some people might think.

Like humans, dogs have about 99% of their genes in common with one another. But a few very distinct genetic differences separate them into some 400 breeds known worldwide.

Researchers who compared dog genes to wolves found that a group of ancient dog types split off first. Later, the majority of canines evolved into three other clusters of dog variants -- hunters, herders and guard dogs -- largely as a result of breeding programs developed over the last few hundred years.

Among those closest to their wild wolf ancestors are the Siberian husky, Chinese Shar-Pei and African basenji.

“One of the most interesting questions still to understand ... is, ‘Why did the wolf keep locked in its genome everything that was necessary to make a Pekingese to a Great Dane?’ ” said Elaine A. Ostrander of the Fred Hutchinson Cancer Research Center in Seattle and a coauthor of the study in the journal Science.

At least two breeds long thought to be ancient, the Ibizan hound and pharaoh hound, were found not to be so old after all. Because of their resemblance to dogs depicted on ancient Egyptian tombs, they had been considered among the oldest of breeds. However, their genes indicate these breeds had died out and had been redeveloped in more recent times, the researchers said.

Two separate breeds recognized by the American Kennel Club -- Belgian Tervuren and Belgian sheepdog -- turned out to be genetically identical.