Sled dogs seem like a niche breed, but they have ancient origins; carved bone and ivory tools resembling dog harness fasteners have been discovered at sites in Siberia dating back nearly 10,000 years. The researchers compared the DNA from ten sled dogs from Greenland, a bone from a 9,500-year-old Siberian dog that was associated with evidence of sleds, and a wolf bone also from Siberia that was dated to about 33,000 years ago.
The ancient dog bone was similar to modern sled dogs and to the ancient wolf, but not to modern American wolves.
This suggests that the sled dogs in the Iditarod can trace their ancestry back to Siberia, and that they are not a modern breed originating only a few centuries ago, as one might have thought given their current use.#6315•
Most domestic dogs have multiple copies of a gene that is useful in digesting starches, widely viewed as a way that dogs became better able to live with humans and our carb-reliant diets. Even among humans, populations such as those from East Asia, where rice has been a staple for many thousands of years, have more copies of the gene for starch digestion than those populations from places where starches are not as major a food source.#6314•
Indigenous populations in the Arctic fall into the latter category, and, no surprise, so do the sled dogs. The sled dogs do have genes that help them digest the fatty acids that are prevalent in a diet heavy in well-larded meat. One of those genes is similar to a gene found in polar bears, though of course the bears and dogs have not shared a common ancestor for a very long time, illustrating the way that evolution uses different solutions to solve the same problem.#6298•
She also debunks the notion that wolves live in strict social hierarchies, with a single alpha pair, and that the dominance relationships in a pack are carried over into dogs, with humans the "alpha" individuals. First of all, social status in animals is complicated, particularly for big-brained species like wolves.
Dominant individuals don't always get their way, and different wolves can approach being alpha differently.#6311•
A great deal of research on wild wolves has shown that they have markedly different behavior from dogs at the get-go, including care of the young by both parents, not just the mother, as is the case for dogs. Though both use their noses in ways that make humans seem effectively scent-blind, wolves and dogs emphasize smell differently, with wolves using it as their exclusive way of interacting with the world as pups, and dogs relying on a combination of sight, smell, and sound#6307•
Another much-touted difference between wolves and dogs is a dog's ability to recognize when a human points to something. If you present the animal with two bowls of food whose contents aren't visible to it, and point to the bowl with the snack, will the animal go where it's directed? Again, sometimes.
Dogs generally do better than either wolves or chimpanzees at this task, particularly when they are young (and are on a par with two-year-old children), although if the wolves have spent a lot of time with people they catch on more quickly.
A key to success seems to be the ability of the animal to look the demonstrator in the eye, something wolves are simply not as prone to do.
The results have caused researchers to wonder about whether dogs and wolves have similar abilities, but the ages at which they take hold are different in the two animals.#6319•
I am intrigued by the idea that cultural biases have shaped the way we view domestication, and I think that vilification of wolves has probably clouded our opinions about how dogs evolved. But I am not convinced that it is only our Eurocentrism that makes us hold wolves apart. Instead, the dog-wolf divide illustrates yet again just how intertwined genes and the environment are in producing behavior.
Yes, you can get a wolf puppy to play fetch, and be petted, and walk on a leash, so wolves obviously possess whatever genetic material is required for such interactions.
But you have to live with those puppies 24/7 for several weeks before that becomes feasible, whereas a dog will oblige you with affection with a fraction of that type of contact.
At the same time, you cannot simply grab a feral stray dog off the street and expect it to sit, stay, or even refrain from biting you.
And the ability to play with an object, or rescue people in distress, varies widely across breeds, and individuals, and when and where it happens.
These behaviors are more likely to occur in dogs than wolves, but they are not universal.
This variability also casts some doubt on the generalization about one species or the other from a round of tests using just a dozen or so individuals.#6302•
The differences between dogs and wolves illustrates the point I have been making all along: behavior isn't something that is unilaterally drawn from a gene or group of genes, and it isn't something that emerges from an experience during puppyhood. Instead, it's both.#6294•
To understand this, we need to delve deeper into what domestication really means. Many people use the word as though it is synonymous with tameness, or lack of aggression, hence the aforementioned tendency of dogs to be friendly and wolves not so much. Anthropologist Richard Wrangham points out that aggression comes in two basic flavors, reactive and proactive, a distinction first made by psychologist Leonard Berkowitz in 1993.#6303•
Reactive aggression is the kind that occurs when a wolf snaps at a rival during a fight, or a child hits a classmate who snatched a desired toy. It is immediate, emotional. Proactive aggression is planned, the kind manifested by premeditated murderers.#6299•
But domestication is more than tameness. An individual animal can be tame, because it has become accustomed to being handled by humans. Species differ in the degree to which they will respond to such treatment.#6297•
Charles Darwin, in his work on domestication,20 was one of the first scientists to note that in addition to being less aggressive, domesticated mammals such as dogs also have floppy ears, white spots in their fur, curly tails, and white feet. At least a subset of these characteristics also appears in domesticated cows, horses, and cats when compared with their wild forebearers.
Domesticated animals also tend to be smaller, with shortened faces and relatively smaller brains, than their wild cousins.#6295•