Science Frictions

Dogs and Us

By Priscilla Long | November 2, 2011
Photo by Gunnar Ries
Photo by Gunnar Ries

 

We, my sibs and I, grew up on a dairy farm, and our family comprised dogs and humans (and cats). We were a mixed-species social group. Our first dogs were collies—Zeppy, Laddie, Peggy, Bo. Later we cohabited with border collies, those compulsive herders—Robbie, Meg, and Princess the Sentinel. Our farmhouse lacked locks, but Princess was ever-eager to eat up interlopers. Later still came the German shepherds—Meg, Lady, Prince.

Dogs—there are 500 million currently alive—evolved from wolves, specifically from Canis lupus, at least 15,000 years ago. A burial site discovered in Mallaha, the upper Jordan Valley of Israel, contains the 12,000-year-old bones of an elderly human. The skeleton’s left hand embraces, with unmistakable affection, the bones of a puppy. Dogs are morphologically distinct from wolves, and this pup was an early dog. The tenderness of the connection is clear. This puppy was no adversary, no answer to What’s for supper? This puppy was a person’s best friend.

Old bones are one measure of when dogs began diverging from wolves. The molecular clock—which measures base-pair changes between the DNA of a fossil wolf and that of a living dog (through the generations, the changes in the genome take time)—is another. The molecular clock estimates that dogs might have begun diverging from wolves as long as 100,000 years ago.

Dogs no doubt evolved from follower wolves, wolves that hung around human camps, perhaps sharing kills, perhaps feeding on cast-off scraps. Follower wolves and their dog descendants were, by far, the first domesticated animals.

We human hunters and wolf hunters had much in common. We both hunted in packs. We both hunted the large, hoofed mammals (mammoth, moose, deer). We both established camps or rendezvous sites for individuals not hunting (such as females tending newborns).

Wolves are not dumb. They devise ingenious hunting strategies. A pack of six will break up. Two wolves will drive the doomed deer into an ambush set up by the others. Or again, one wolf will grab the nose of a huge, furious moose. The moose will begin flinging the wolf about, a life-threatening joy ride. Meanwhile his or her packmates bite flank and belly until the unfortunate ungulate loses too much blood to continue. (Did humans with spears happen along and help out?)

Jon Franklin, author of The Wolf in the Parlor, notes that unlike solitary hunters, a wolf can risk biting the nose of a beast because the pack will care for a wolf injured in the hunt. Wolves take care of their own. As do humans.

Wolfpacks have alpha males and alpha females, and wolf pups learn submissiveness. A wolf pup can imprint on a human. As Jared Diamond elaborates in Guns, Germs, and Steel, of all the animals in the Kingdom, very few can be domesticated. The ability to be submissive within a social group is a quality quintessential to domestication.

If our ancestors did occasionally sup on a pup in a follower pack, wouldn’t they have chosen to get rid of an aggressive one? An unconscious breeding program. A Russian breeding experiment on wild foxes (also canids), begun in 1959 by Dmitry K. Belyaev of the Institute of Cytology and Genetics in Novosibirsk, chose tameness and only tameness as the criterion for breeding. Within 35 generations these foxes were docile and eager to please. Remarkably, their ears had become floppy, their tails shorter and curled, their legs shorter, and their jaws and teeth changed. This perfectly illustrates the evolution from wolf to dog.

Down on the farm, we were devoted to our dogs. The dogs obeyed our commands. They brought in the cows and they guarded us and they loved us. In return we gave them dog food, dog bones, playtime, herding time, and the constant company of ourselves. You could say that our dogs had domesticated us.

It may have been the wolf that made the human into a dog’s best friend.

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