For a greater understanding of the encultured brain and body…

Foxy Evolution

Posted by dlende on August 28, 2008

Here’s a great video that shows how selection can work its effects–in this case artificial selection, demonstrated through the work of the Russian Dmitri Belyaev and his tame silver foxes. Still, what I find most striking about this video is the analogy to ourselves.

Jim Rilling, a neuroanthropologist at Emory, once commented to me that humans are wired to cooperate (in his latest work, he’s doing neuro-imaging on what happens when people don’t reciprocate, having researched the neural bases of cooperation earlier). The example Jim used has stuck with me ever since. Imagine 50 chimpanzees trying to sit down and watch an introductory lecture together. Pandemonium with those chimps. For us, it’s the most mundane sort of thing. People do it everyday around the world.

What is clear from primate research is that our nearest relatives already have established local behavioral traditions, self awareness, and advanced social cognition. What I find striking about “culture” is how it works all these into new, networked, holistic forms. In my mind, culture does not represent a single adaptation. Thus, conceiving of “culture” as non-genetic information transmission (the typical stance in cultural evolution research) misses most of what culture is about—public, meaningful, enacted, systemic, and coordinated, to go with some choice modifiers.

But just as being “domesticated” for wild foxes brings with it a whole bunch of linked changes, so too might be becoming “encultured.” More specifically, there might be significant selective pressures on certain human adaptations. For example, I mentioned the physiological and neural bases of speech production recently. Terrence Deacon in The Symbolic Species shows how inter-related brain areas can expand differentially with selective pressure on language capabilities in early childhood.

Is that the one adaptation? Probably not (one is the loneliest number when speaking of culture). But the video presents an analogy for how to think differently about cultural evolution. All that linking together of elements already there (social cognition, cooperation, self) could happen as those elements suddenly become expressed and networked in very different ways as new selective pressures act on people. Language production and coordination represents one possible selective pressure.

The reason I highlight this is because there are a lot of evolutionary proposals out there speaking about the adaptive benefits of this or that element of human behavior and being. The evolution of religion is one prominent example of late. But that might not be the right way to think about our past evolution, looking for specific adaptive benefits for prominent human features that seems to still separate us from other animals.

As Isaiah Berlin might say, these types of researchers are hedgehogs, digging into one core idea to explain everything again and again. But culture is definitely a fox, jumping from idea to idea, thing to thing. So the evolution of domesticated foxes might give us some ideas about how we also domesticated ourselves.

4 Responses to “Foxy Evolution”

  1. gregdowney said

    WHOAH! I had heard about these experiments, but I had never seen the foxes’ behaviour or heard it discussed so completely. I’m stunned. Amazing stuff. Thanks, Daniel, for posting this!

    But I’m struck by what Rilling suggests, and I think Belyaev’s foxes sort of demonstrates something contrary to what she is saying (or at least, one way that I might be interpreting what she’s saying). That is, Belyaev got this sort of behaviour by relatively simple selective mechanisms; he simply screened for response to the glove in the cage, whether an animal was aggressive or fearful, or whether it was calm or curious. The foxes did not start out ‘domesticated’; they became domesticated through this selection process. He ran the same sort of selection a few times, and in ten years (I don’t know how many fox generations), he got this cluster of different traits, all brought on by the simple selective mechanism of ‘if you bite me, you don’t breed.’

    The foxes became ‘wired’ this way through this selection process. In addition, the immature foxes, with a different set of initial response patterns (or instincts) started to get abundant feedback in relation to the new early profile. Because they didn’t bite humans when young, they didn’t have to be in cages, they got to run around, they got scratched and cuddled by humans, etc. The opposite can happen with a domesticated animals that is neglected and ‘goes feral.’ Genes are the same, and the animal likely had the early developmental patterns of a domesticated animal, but the subsequent experience (and lack of ‘domestic’ behaviour reinforcement cycles), and the animal goes feral (though not exactly back to ‘wild,’ of course).

    So if Rilling is saying that humans come into the world pre-destined for cooperation, I would disagree with this. We know that feral children, neglected children, abused children, and some others can wind up very ‘un-cooperative.’ They’re no less ‘human’ because of this, of course, but they may have started with the same early developmental behaviour patterns, the same mechanisms that produce a proclivity for cooperation in most human adults (though not all), but they didn’t come to a normal profile because the support and response patterns in the environment were not cultivating this trait.

    In other words, I suspect that we, like Belyaev’s foxes, are ‘domesticated’ animals — it’s just that we do it to ourselves. We have lots of other traits of domestic animals that point to this same conclusion (such as high body fat, under-developed flight and fight responses, exaggerated curiosity, some juvenile physiological traits that continue into adulthood like the floppy ears of Belyaev’s foxes, etc.).

    Although I like your reference to Berlin’s discussion of foxes and hedgehogs, I think it’s also appropriate to talk about Gould’s criticism of the trait-specific adaptationism of many evolutionary theorists that he wanted to criticize. That is, a lot of evolutionary theorists — especially those from fields outside of evolutionary science (I won’t name names, but our readers know the Usual Suspects) — tend to think of an organism as a collective of discrete and disarticulated traits, each one of which is independently selected for. Organismal biology clearly shows that traits are not isolated and independent, but often vary jointly in intriguing ways, like ‘tameness’ and colour, ear shape, and facial structure in foxes. Although a trait may offer a selective advantage, natural selection acts on the organism as a whole, so the ‘package’ of linked traits either gets passed on or not. The fox doesn’t get to pick which trait it keeps; all those bundled with the trait that gets selected (in this case, artificially) wind up tagging along for the evolutionary ride.

    What a great video though. I’m sure to use it when I teach this semester. Thanks a ton for pointing it out.

  2. Adam Barsella said

    I saw more about this and the domestication of dogs on a Nova program about a year ago. It was very interesting; I definitly recommend checking it out.

  3. dlende said

    Greg, a great comment. With Jim, all I think he would say is that cooperation plays an important role in human evolution, and that is reflected in the way our brain functions. How much of that is due to genetics, epigenetics, environmentally-induced plasticity is an open question, though he would probably favor including some genetics. I’ll send him this post and ask him. I don’t think he would say “pre-destined”, though he would likely say that we are more predisposed to social cooperation than chimpanzees…

    I was the one making the suggestion about a relatively simple selection pressure, with an accompanying cluster of traits, as a different way to think about human/cultural evolution. As you indicated, sometimes the trait-specific adaptationism becomes the dominant mode of evolutionary analysis.

    For something like culture, particularly its more systemic and integrative aspects, it might prove productive to think about “joint variation” as a better evolutionary model. That still leaves open what specific selective pressures acted when (it’s not just one over two million years, that’s for certain). But a bundled approach to cultural evolution, with a focus on basic selective advantages (mordibity, mortality, foraging, social relations, kin selection), is a different model than trait-specific adaptationism and modeling biological and cultural evolution separately.

    Looking at the video again, I agree that certain things are related to the environmental feedback, such as going into the home and responding to names. And those things jump out at us, because they make the foxes seem even more dog-like. But I wouldn’t want to place it all on early feedback.

    I do think there are different genetic patterns in the feral and domesticated foxes as well (likely more in terms of expression than changed code…?). Much of that is due to an experience at my sister’s farm. Yes, I am going to use an anecdote!

    At that time my sister had some pet rats, very white, quite friendly and tame. During some construction in her barn, a wild rat’s nest got exposed. The mother rat took off, and there were some newborn rats.

    My sister decided to “take in” these barn rats, and initially kept them in a large feed tin with a lid. I remember how bristly their fur was, such a sharp contrast to the soft white coat of the domesticated rats.

    Each time someone would take the lid off, the group of baby rats would be huddled together in the middle of the bin. But with the noise and light, they would immediately shoot at full speed to the sides of the bin. That same “flight response” as in the foxes.

    A very adaptive response when faced with a large animal that is both a predator and capable of crushing a rat underfoot. And completely different from the way her tame rats acted. The Balyaev video captured the same thing for me, but with foxes.

    As you say, we likely domesticated ourselves. That’s a very different way of thinking than proposing the adaptive features of culture or religion, as if these were somehow separate from people themselves. It’s also different from proposals of social or Machiavellian intelligence and the runaway human brain.

    But to go back to Gregory Bateson, in selective terms, what was the difference that made a difference? If we get this suite or cluster of traits and effects bundled together, what was the specific adaptive component? It certainly is something fun to think about.

  4. dlende said

    I wrote Jim Rilling to get his views, and here’s what he replied: “Hi again Daniel, I just read through your blog. Interesting discussion. I think you captured my view accurately in your reply to Greg. When I think of cooperation, I think of “prepared learning”; the idea that we come into the world with the ability to easily learn to cooperate. There is something different about the human brain that allows us to learn to cooperate with nonrelatives more readily than other primates. It may be similar to language – we come prepared to learn symbolic communication more easily and to a greater extent than other primates.”

    So there we go, words from the man himself!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 349 other followers

%d bloggers like this: