Scientists used to believe dogs descended from several species, including the wolf and jackal. However, a recent scientific analysis upheld the more current theory that their primary ancestor is the wolf1.
History of the Dog
The earliest known domesticated dog was found at a German burial site dated 14,000 BC. Dogs likely worked cooperatively2 with humans to locate and announce the position of prey wounded by hunters. But, a recent study in the journal Science looked at mitochondrial DNA from dogs, wolves, coyotes, and jackals. They concluded that wolves and dogs may have genetically diverged much earlier. As long as 135,000 years ago.
But, the findings aren’t conclusive3,4,5. The current consensus among most experts indicates the split from wolves occurred around 30,000 to 35,000 years ago.
Over the centuries, dogs underwent drastic changes from natural selection and selective breeding. This resulted in the vast array of hair colors, sizes, and temperaments we see today. We distinguish about 200 to 400 different breeds worldwide. And this doesn’t even count the “mutts” of the world6.
However, the American Kennel Club only recognizes 140 breeds. They define a breed as a relatively homogeneous group of animals within a species, developed and maintained by man. This is only the AKC’s definition of breed. It doesn’t mean there aren’t other breeds.
Domestication of the Dog
We assume wolves were the first species we ever domesticated7. But no one knows how man and wolf came together to create domesticated dogs. One more plausible theory is that wolves started following early hunters, gatherers, and migrants. The wolves discovered they could easily help themselves to the food the early humans left behind. Consequently, this was a win/win situation. The well-fed wolves were no longer a threat to humans but also alerted them to dangers. They probably even helped to fight off enemies and predators.
Humans likely integrated wolf puppies into their band or group. Possibly after their parents were killed while hunting or while defending the pack. Likely they kept the friendly and social wolves and killed those who showed aggression toward them. The first step towards domestication.
Early humans probably enjoyed wolves’ instinct for hunting, game retrieval, and defense of the group. Likely they trained the animals to perform other services.
Modern Times
Today, after a long journey together, our furry friends are so in tune with us that they are the only species that understands human body language8. When you get up from a chair, your buddy knows if you are going to the bathroom or getting ready for a walk.
A dog is also the only animal that understands the concept of pointing at something. Your buddy knows to look in that direction if you point at anything with a stretched-out arm. Any other animal will just stare at your arm9.
They can also be trained to fetch three-dimensional objects when shown a two-dimensional picture of that object. This is a level of abstract thinking human children only develop between the ages of one and two years. We consider dogs to have the intelligence of two-year-old children and share similar learning abilities10.
Our understanding of dogs and what they are truly capable of keeps evolving and surprising us. But one thing is clear; they are very smart animals.
References:
- PBS Online Nova Science: The Wolf Connection (November 2000)
- National Geographic: And Man Created Dog (November 2011)
- PBS Online Nova Science: The Wolf Connection (November 2000)
- K. Kris Hirst: How were Dogs Domesticated? (About.com, Archaeology)
- Mark Derr: The Wolf Who Stayed (The Bark, Issue 38)
- Sarah Hodgson: Breed Determines Traits (New York Times, 11/30/1997)
- National Geographic: And Man Created Dog (November 2011)
- Clive D. L. Wynne, Ph.D.: How well do wolves and dogs understand people? (Wolf Park Experiment, 2009)
- Jennifer Viegas: Dogs Really Do Understand Us (Discovery News, 02/08/2012)
- Stanley Coren, Ph.D., F.R.S.C.: What Are the Limits of Canine Learning? (Psychology Today, 07/27/2011)
