According to archeologists, dogs and humans began their familiar relationship about 15,000 years ago. The fossil record supports this, as does a study of DNA of the hair of some 650 dogs. There is another DNA study that puts dogs and people together much earlier, but that one has no archaeology record to confirm it.
What’s not in dispute is the domestic dog’s ancestry, and this surprised me. A dog’s mitochondrial DNA differs from a gray wolf’s by a mere 0.2 percent. (Coyotes, in contrast, have a 4 percent difference.) So, in one sense dogs are grey wolves that we humans have bred selectively to work for us or serve as our companions and pets.
Yet it is obvious that dogs are not wolves. They don’t look like wolves except in their broadest outlines, they don’t act like wolves, and they are loved and celebrated in the popularimagination whereas wolves are feared and hated.
So the question is how did dogs evolve from wolves? Were their ancestors the most passive of the pack, the ones that hung around human camps, willing to do the humans’ bidding? Did people then deliberately breed those wolves that were most attuned to them, understanding their value?
Or could dogs have essentially domesticated themselves, as docile animalsmated, producing a human-centered species? And did those dog precursors possess some kind of intelligence that enabled them to read human social cues?
We have only to look around us to see more diversity among dogs than there is for any other species. Surprisingly, geneticists tell us the dog is a basic template that can be diversified with the variation of a fairly small number of genes.
A single gene determines if a dog will have the short, squat legs of a dachshund or the long, elegant legs of a greyhound. One gene controls for color in Labrador retrievers, another for floppy ears.There is even a single gene that will make distinctive white “socks” on a black Lab (that disqualify it from meeting the breed standard).
When humans breed dogs, we breed them for us—to suit our fancy, primarily, and sometimes to help us accomplish certain tasks. To cite a recent example, the labradoodle—a cross between a poodle and a Labrador retriever—was initially made to create non-shedding guide dogs because the standard ones—German shepherds, Labs, and golden retrievers—could not be used by people with allergies.
Well, I’m a long way from remembering the dogs of my childhood, but I’d enjoy hearing some of your stories about dogs.
Jerry Lincecum is a retired English professor who now teaches classes for older adults who want to write their life stories. He welcomes your reminiscences on any subject: firstname.lastname@example.org