Marmaduke and the Taco Bell Chihuahua Are Cousins

Although many breeds of dogs exist, they are more similar than not.You would never think Marmaduke, the enormous great dane of the newspaper cartoons, and the tiny Taco Bell chihuahua are close relatives. But the fact is, ALL dogs are pretty close relatives. Scientists now believe that all dogs, including the semi-wild dingoes of Australia, Arctic huskies, Shetland sheepdogs, great danes and tiny chihuahuas, are descended from only two original domestic dogs. DNA evidence also suggests that dogs are all derived from wolves, not coyotes or jackals.

The DNA evidence further suggests that dogs were first domesticated about 100,000 years ago. However, the first dog fossils, found in Europe and Asia, date from only 14,000 years ago. The scientists who did the DNA study think that early dogs looked so much like wolves that they can't be distinguished from them in the fossil record until about 14,000 years ago. People later took their dogs with them as they spread out over the globe, to Australia, the New World, and the Pacific Islands. Wild dogs recently discovered in the southeastern United States may be descended from the dogs kept by the Native Americans.

Domestic dogs are smaller than their wild forebears, with smaller brains, less acute senses, and smaller teeth. In appearance and behavior, they are immature, puppy-like wolves.

About the Author

Sandy Becker, MA

Sandy BeckerSandy Becker received a BA in history from Pomona College. She then earned two MAs in Biology, and now has 25 years of experience in developmental biology research, working with mouse embryonic stem cells. Sandy began writing science articles about ten years ago to share her knowledge of science. She is currently studying for her third MA, in science journalism.