It’s an interesting discussion, focusing on the famous The Spandrels Of San Marco paper, but also talking generally about SJ Gould’s ego (it was big and ambitious), and how to properly do an evolutionary research program.
DSW: What’s the right way to do it? When I talk about the adaptationist program, I say that an adaptationist hypothesis is often the best way to start because it doesn’t require much information to know what an organism should be like to be well adapted to its environment. So it’s a good starting point, although certainly not the end point. Then the inquiry can go in a direction where you decide—as with the color of blood, by the way, an example that I use myself—that this is probably not an adaptation. You can arrive at the truth of the matter. But thinking in adaptationist terms is part of the process. So what’s the way to do it right and what’s the role of adaptationist thinking in an appropriate procedure?
RL: Well (laughs), you’re asking me what the right way to do it is. I think the right way is to start with the sentence: “We do not have any hard evidence of the forces leading to the following evolutionary change.” There has to be a prelude to the discussion of evolutionary change to make it clear that although the theory of natural selection is very important and happens lots, there are other forces, or other mechanisms, that lead to change and we are not obliged by being Darwinians and being evolutionists to invent adaptive explanations for all changes. I think that’s where you have to start. Then, as either a philosopher or biologist, ask in a particular case what is the direct evidence, besides the desire that we want to find something, that a particular story is true or not true. Most of the time we’re going to have to say that this happened in the Eocene or the Paleocene and we haven’t the foggiest notion of why it happened. I think the admission of necessary ignorance of historically remote things is the first rule of intellectual honesty in evolution.
There’s also some talk of Dobzhansky and the limitations of his work.
RL: Yeah, right. He was a very bad field observer. Theodosius Dobzhansky never, in his entire life, nor any of his students, me included—I would go out in the field with him, actually–ever saw a Drosophila pseudoobscura in its natural habitat.
DSW (laughs): Yeah, OK!
RL: We didn’t know where they laid their eggs. We couldn’t have counted the number of eggs of different genotypes. How did we study Drosophila in the wild? We went out into the desert, into Death Valley, we moved into a little oasis, we went first to the grocery store, and bought rotten bananas. We mushed up the bananas with yeast till they fermented a bit, we dumped that into the paper containers, put it out in the field and the flies came to us.
DSW: Right! No naturalistic context whatsoever.
Ouch. Sounds a bit like zebrafish research.
You’ll have to follow the link to see what he has to say about sociobiology and evolutionary psychology. It’s not flattering.