When I was in the middle of writing the contemplative computing book, we adopted a dog, an elderly Carolina named Christopher. I hadn't lived with a dog for at least thirty years, and we had two aging cats, so it was on the face of it an absurd thing to do; but it turned out to be a great experience. (Alas he died in October.)
Christopher, via flickr
One of the things it got me thinking about was the coevolution of humans and dogs, and the features of Homo sapiens that reflect our ability to change our physical environment, or to reliably make tools. According to some evolutionary biologists, for example, we've evolved to eat cooked food: with our ability to make fire, our jaws and teeth got smaller than our primate cousins. We're more carnivorous than they are, but we use our teeth to chew cooked meat, not kill it.
Dogs can eat cooked meat too! via flickr
Dogs clearly evolved to live with humans: their ability to read our moods, to fit themselves into families, and to do essential jobs like hunting and guarding (or these days, hiding slippers, rearranging oven mitts, and retrieving glow-in-the-dark balls), were all either spontaneous responses to environmental opportunities, or the product of breeding.
Being sociable, via flickr
The Washington Post reports on new research that further documents how humans and canines coevolved. "Swedish researchers compared the genomes of wolves and dogs," they write, "and found that a big difference is dogs’ ability to easily digest starch. On their way from pack-hunting carnivore to fireside companion, dogs learned to desire — or at least live on — wheat, rice, barley, corn and potatoes." In essence, they made the same evolutionary change that humans did when they moved from being hunters and foragers to farmers-- and did so at about the same time that humans did.
Axelsson and his colleagues examined DNA from 12 wolves and 60 dogs. The wolf samples were from animals from the United States, Sweden, Russia, Canada and several other northern countries. The dogs were from 14 breeds.
The researchers compared the DNA sequences of the wolves and the dogs (which are subspecies of the same species, Canis lupus) and identified 36 genomic regions in which there are differences that suggest they have undergone recent natural selection in dogs.
In particular, dogs show changes in genes governing three key steps in the digestion of starch. The first is the breakdown of large carbohydrate molecules into smaller pieces; the second is the chopping of those pieces into sugar molecules; the third is the absorption of those molecules in the intestine.
The history of domestication is still shrouded in some mystery, but this is
“a striking case of co-evolution,” said Erik Axelsson, a geneticist at Uppsala University. “The fact that we shared a similar environment in the last 10,000 years caused a similar adaptation. And the big change in the environment was the development of agriculture.”...
The evidence of natural selection in the number and efficiency of key digestive enzymes supports the hypothesis that dogs may have domesticated themselves as a way to exploit the garbage of permanent human settlements….
Accompanying the dietary change — and probably evolving along with it — were behavior changes that allowed dogs to tolerate living near people and ultimately being adopted by them. The Swedish researchers found strong evidence of genetic differences in brain function — and particularly brain development — between wolves and dogs, which they have not yet analyzed.
So why does this matter? I think looking at our evolution, and in particular at the ways our tools and environmental changes have helped shape us as a species, can help us better understand the fundamentals of our relationship with technology, and better appreciate how incredibly good we can be when we have tools that work well-- and how poorly today's information technologies make use of our ability to merge with our devices. A really broad view of human evolution would have a place for domesticated plants and animals too, as they've become parts of our environment as well.