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Dogs: Do We Know Less About Them than They Know About Us?

Dogs that we have made part of the family seem to know plenty about us. And there’s probably no closer bond between animal and human that the bond that forms between us and our pet dogs. So isn’t it amazing that we know so little about where our best friends came from or when they were first transformed from marauders to companions.

What Scientists Believe About the Evolution of the Dog

Until recently, the dog’s ancestors were believed to include coyotes, jackals and wolves. And it was believed that domestication occurred 12,000 to 14,000 years ago, based on the oldest fossil evidence available: dog bones found together with human bones in caves all over the world.

But these beliefs were challenged in the late 1990s when Robert K. Wayne of the University of California, Los Angeles undertook a study that would unravel the dog’s genetic evolution once and for all. This study used molecular biology and statistical methods to compare the genetic differences between dogs, wolves, coyotes and jackals. After all, genes would tell a far different and more accurate story than bones.

Wayne and his international team of molecular biologists based the study on mitochondrial DNA from 140 dogs of 67 breeds; 162 wolves of 27 populations in North America, Europe, Asia and Arabia; and from a collection of coyotes and jackals.  

As explained by Dr. George Johnson in “On Science,” the focus on mitochondrial DNA makes it possible to clearly identify ancestors because mitochondrial DNA comes only from the mother.

Bottom line: the relatively small differences between dogs and wolves compared to those between dogs, coyotes and jackals convinced the scientists that dogs are domesticated wolves.

The Domestication of the Dog

The study was unable to settle the question of the dog’s geographic origin. But most surprising was the conclusion that wolves could have been domesticated not 14,000 but 100,000 or more years ago. While highly controversial, it seems plausible when you realize that fossils of wolf bones have been found together with human bones dating earlier than 100,000 years ago.
 
As written by Christine Mlot in “ScienceNewsOnline,” June 28, 1997: “Tamed wolves might have taken up with the hunter-gatherers without changing in ways that the fossil record would capture. The dogs-in-process probably would have dallied with wolves as packs of humans and canines traveled the world.”

Mlot continues, “Once people settled and started to farm, they might have begun selectively breeding their wolf-dogs into herders, guards, and different kinds of hunters.”

What Dogs Seem to “Know” About Us

Now isn’t it ironic that we’ve known so little about our best friends for so long, while they apparently “know” so much about us.

For example, if you’ve bonded with a dog, have you ever noticed that it seems to know when you’re depressed or not feeling well, even though you didn’t tell it so? What do dogs really know about us?

To quote Brian Hare of Harvard University, “It looks like dogs really do understand what we are trying to tell them, they are thinking about what we want, and they understand that we are trying to communicate.”

Hare ran one of three studies published in “Science” magazine, November 2002. The study compared the accuracy and frequency with which chimpanzees, wolves, dogs and puppies understood various cues.

Bottom line: Even though the chimp is closest to humans (96% of their DNA is identical to ours!), and even though the wolf’s brain is bigger than the dog’s, the dogs and puppies won.

And while the dogs were expected to outperform the puppies because of their longer experience with humans, puppies as young as 9 weeks correctly recognized the researchers’ subtle cues! Mind you now, these tests did not make it possible to use the sense of smell. “Dogs have a talent for reading social cues in a very sophisticated way,” Hare said.

Marsha Walten of CNN quoted dog behavior expert Patricia McConnell, a zoology professor at the University of Wisconsin, Madison. “Domestic dogs follow humans like a laser and watch the behavior of their humans with a focus that is astounding. This opens up big and interesting questions about how social intelligence is passed on genetically.”

Walten said McConnell explained that we still don’t know which human cues are perceived by dogs as most relevant. “Perhaps you’ve taught your dog to sit, and you want to show this off to your friends. You say ‘sit’ and he just looks at you,” McConnell said. She explained that the dog may have learned to sit by watching your body language rather than your words, and that your body language would be different in a room full of people than it was during training. McConnell’s experience working with aggressive dogs had shown that a tiny difference in human head movement made the difference between a calm response and an attack.

And so, it really does look like dogs know more about us than we think.