Doug Lindstrand/Getty Images
Doug Lindstrand/Getty Images
According to a new hypothesis put forward by an international team of geneticists and archeologists, dogs may have been domesticated in two different places from genetically distinct wolf populations in Europe and in East Asia.
Dogs today, according to the study published in Science last week, are the result of the interbreeding of these two quite distinct populations from Europe and East Asia. And they continue to bear the genetic traces of not one, but two distinct — and now probably extinct — species of ancestral wolves.
The science is complicated and involves the analysis and comparison of ancient dog remains and modern dogs, together with information about the age and distribution of dog remains across the Eurasian continent. There is still so much we don't know — the evolutionary history of dogs is complicated and there are uncertainties about mutation rates and generation times, and the archeological record is incomplete — so the hypothesis remains just that for the time being, a hypothesis.
But what a suggestive one!
Dogs are the first species, animal or plant, to be domesticated by humans, long before the advent of agriculture. But, presumably, not as the result of any conscious decision or plan on the part of humans.
There is a familiar and plausible story about how this might have happened.
The setting: Ancient humans encamped around a fire in a forbidding wilderness. Wolves encircled them beyond the perimeter of light, unable to attack but presumably satisfied to scavenge what they could pick off or pick up at the edges.
We can imagine that the wolves were a controllable danger at the periphery that came, in time, to serve as something of a buffer — that is to say, a living alarm signal of the approach of strangers (animal or human) in the dark night. The presence of wolves, outside the ring of light, at a safe distance, was a sign that all was normal on the outside, that is was safe to fall asleep.
Against the setting of this sort of interdependence, it is easy to imagine that some wolves — those brave enough to move in closer but also sensitive enough to do so in a way that didn't provoke violent attack on the part of the humans — would have had more access to uneaten food or other remains the people tossed aside.
Wolves who were savvy to the state of mind of nearby humans — presumably most were not — would have been rewarded with a reproductive advantage relative to their fellows. And for their part, humans comfortable with the making of a cross-species alliance — friendship — would have been likewise rewarded by, among other things, ever greater security.
After a few generations you'd have wolves and people growing not only increasingly tolerant of each other but also increasingly cooperative. Dogs, that is to say wolves, who were at home in the orbit of people would in this way have just "showed up" in the experience of people. Or, perhaps we should say, people who found it natural to look at dogs as potential kin made their appearance on the stage of life. And, crucially, not as the result of any conscious plan or act of bio-engineering. Domestication, then, would have just happened.
Who domesticated whom?
If you think about it, the process I have just described — the story is told beautifully by Neil deGrasse Tyson in the first installment of Cosmos — differs only in degree, and not in kind, from the story of human encounters with other humans. It is the story of the birth of new species but also the establishment of community.
It should not be a cause for wonder, then, that we can look into the eyes of dogs and recognize living beings deserving of our love and care. Dogs are not strangers. They are here because of us, just as, in truth, we are here, in the manner in which we are now here, because of them.
Recent studies show that humans and dogs, when they communicate with each other, experience similar patterns of oxytocin release as humans do in relation to other humans. Oxytocin is associated with attachment. It isn't that dogs are human. No more than it would be right to say that we are dogs. But what it is to be a dog, and to be a human, are not entirely independent of each other.
Life is like that. Its causal dynamics are circular. Life is co-becoming. Another example: There is color in nature — signaling ripeness or fertility or danger — precisely because there are animals who can see. A world in which there were no eyes to see would be a world in which things tended to the black and white.
In general, in the biological and in the social worlds, variation is the thing, not stable or fixed differences. And variation is a field of change and becoming.
Given this, it isn't surprising that the dog "domestication event" happened more than once. (Vision has also evolved more than once.)
The real headline, then, is not that humans domesticated dogs twice. But that humans, always, have been changing and changed by the larger inhabited world in which we find ourselves.
How many times have humans domesticated themselves?
Alva Noë is a philosopher at the University of California, Berkeley, where he writes and teaches about perception, consciousness and art. He is the author of several books, including his latest, Strange Tools: Art and Human Nature (Farrar Straus and Giroux, 2015). You can keep up with more of what Alva is thinking on Facebook and on Twitter: @alvanoe