An Interview with Nicholas Wade
The full interview is here (Link). Below are exerpts from the second half of the interview. I have highlighted in red comments made by Wade which go against or are not supported by the consensus among anthropologists, archaeologists and geneticists.
Esty: discuss how, even though modern humans were around in Africa by 50,000 years ago, it wasn't until about 15,000 years ago that they began settling down and giving up their nomadic way of life. Why did it take 35,000 years for sedentism to develop?
Wade: That's long been one of the paradoxes of archaeology. What I suggest in my book is that a genetic change was required in order to make it possible for people to settle down. Genetic changes take some time to evolve, and just as the earlier big genetic change—the development of language, 50,000 years ago—emerged very recently, I think settling down was the second recent major evolutionary stride. The change, presumably, was to become less aggressive, to be able to settle down in fixed communities, in large enough groups to defend the settlement against other hunters and gatherers.
One piece of evidence comes from paleoanthropology: the thinning of human skulls that seems to have taken place at about the same time. The earlier human skills are very thick, what archaeologists call robust, and then there's a thinning of the skull and the skeleton that takes place between 50,000 to 15,000 years ago. The skulls become more gracile, as if human beings were being domesticated, and this is exactly the sort of change that takes place in the skulls of animals when they're domesticated.
Esty: How would that have worked on the ground? It seems that the first human to evolve a thinner skull would, in a nomadic society, have been at an evolutionary disadvantage.
Wade: I think it's very hard for us to say at present. We can see the trajectory of human evolution, and with luck we'll be able to pinpoint when each gene changed, but many of these most essential genes may have been involved in our social behavior. Presumably we used to live in rather small tribes, about 150 members, not more, which split up as members became less related to one another, because the basis of their association was kinship. Modern societies have taken a step beyond kinship. Our contemporary societies are far larger, and we live in a world of strangers whom we trust to an amazing degree in many contexts. I assume that change in behavior has a genetic basis, so something has made us more trusting in each other and therefore able to live in larger societies. If some mutation happened that made early people more trusting of each other and able to live in larger societies, that might have given them an advantage over tribes living in smaller numbers.
Esty: So, for example, you write that altruism is difficult to explain in evolutionary terms, but you can certainly find examples of it in human society.
Wade: Well, altruism is a basic behavior that is required of any social behavior. Presumably we developed altruistic behavior very early in our evolution, as primates, and if you look at the way chimpanzee societies or bonobo societies are organized, they all seem to be following a definite genetic template. So if you argue that there's a set of genes that shape social behavior that the chimps and the bonobos inherit from their ancestors, then we, too, must have inherited a version of that template, and I see no reason why it should have disappeared in present-day society. It has simply adapted as you would expect any other gene to adapt.
Within that template, in my view, must be embedded genes that shape our behavior, our propensities for aggression, religion, trade, conciliation, altruism—and all these forces must still be acting on our behavior. I think archaeologists have maybe done us a disservice by presenting the past as if it were peaceful and the present as if it were very warlike, because they've feared sending the wrong political message if they suggested that anything about our aggressive behavior today was justifiable. But in doing so they sort of blurred the message that we might have evolved considerably in terms of peaceful tendencies since our earliest ancestors.
Esty: Evolution, of course, doesn't intend to take us anywhere, but you do talk about the idea of evolutionary progress and say, for example, that even if scientific research casts doubt on the idea of humans having free will, we should continue our research or else it would be a "retreat into darkness." So it does sound like you think we might be advancing toward something.
Wade: I think if you look back at the sweep of human history, from 20,000 years ago, say, to today, I think most people would say, well, that's certainly progress. It's far better to live in the kind of society we have right now than to be a hunter and gatherer leading a precarious and harsh existence.
So how can one embed that perception of progress into evolutionary theory? Well, as you say, evolution has no goal, and progress is not part of the vocabulary of evolutionary biology. It seems to me that the escape from this dilemma lies in the fact that, firstly, the human genome responds to its environment—and the most important part of one's environment is the human society in which one lives. So people adapt genetically to the type of society they're living in. The best example of that, though it's not a behavioral change, is the development of lactose tolerance among European societies that depended on cattle.