I really enjoyed reading the transcript of this interview of Richard Lewontin by David Sloan Wilson. They touched on the importance of humility as a scientific virtue, and in a rather indirect fashion, how the lack of it could influence your science. Lewontin also highlighted the importance of understanding the natural history of your study system and described how, without that knowledge, one cannot begin to resolve the evolutionary processes operating in that system. Yet, he also noted, the sociology of science is such that prestige is rarely bestowed on people who do the appropriate experiments on suitable organisms. These observations suggest a sort of trade-off between the pursuit of prestige versus the study of natural history with a desire to understand evolutionary processes in real systems. I also learned that Dobzhansky was not much of a naturalist, which I found interesting because I always assumed that he was more of a naturalist than was Sewall Wright. Even though he worked on guinea pigs in the lab and cows in farmer’s herds, Wright could have been a better naturalist than Dobzhansky!
The interview began and ended on Sociobiology, which it seems was what Wilson really wanted to address. Lewontin criticized Sociobiology, and Wilson himself, for starting with the assumption that all traits might be adaptive, i.e., the “adaptationist program”. He then suggested that the difference between being a population geneticist and an evolutionist is the ability to use experiments to test hypotheses about all possible evolutionary processes (those things that you learned in introductory biology would violate Hardy-Weinberg Equilibrium). This is a great point!. It should be heeded by those purporting to elucidate evolutionary processes from patterns of DNA sequence mutations. One solution to this problem is to analyze patterns of DNA sequence mutations produced during evolution experiments in which known evolutionary processes are applied as treatments. However, this will still not help explain why the leopard got its spots or precisely why some human populations acquired the ability to digest lactose as adults. Lewontin outlined a more general form of this solution, to which Wilson rather tellingly responded, “Uh Huh. Interesting.” Clearly, there is a real conundrum here. It is either ethically inappropriate or technically impossible to conduct evolutionary experiments on humans and other charismatic megafauna, yet the evolution of these organisms piques the interest of all of us. This problem drives many people to cut scientific corners in their desire to study evolution in these organisms, thereby conditioning many untestable adaptationist stories. Could its also be at the root of the assertion by some evolutionary biologists that evolution is something more than the change in a population’s allele frequencies across generations?
Lewontin also used Wilson’s fixation on Sociobiology to launch a critique of the niche as a fixed thing rather than something constructed by coevolution (and, I would argue, phenotypic plasticity) between the organism and the environment, thereby reminding us that he pioneered the concept of niche construction. He goes on to claim that there is no such thing as an empty niche; that “There are no niches without organisms.” This is an important issue with which evolutionary ecologists must wrestle. It also can be construed as a critique of the Central Dogma of molecular biology, illustrating that at least some population geneticists share some common ground with the current crop of evolutionary developmental biologists.
Finally, Lewontin demonstrates in this interview that he is most interested in fundamental issues. Thus, the most important lessons that I learned from reading this interview are these: don’t get distracted by controversies and superficial issues; be humble and focus on the fundamentals.