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.
I posted on this on my Facebook page a few days ago, and highlighted the same two paragraphs PZ did, as I really liked them. I also went off on a bit of philosophy,and wrote this:
“This is an interview with Richard Lewontin about the famous paper by Gould and him about how some traits arise evolutionary as “unintended consequences” – spandrels, rather than as specific adaptations. Aside from the biology, I found it interesting because it addresses the broader issue of how human beings make up stories to explain things all the time, even when we have no idea if the causal connections we describe are true.
In the following exchange, the “adaptationist program” mentioned by DSW is that of having a story that a certain trait arose because it had a selective advantage – in general, that there was a causal chain that explains why the trait came about. Lewontin is doubtful that we should start with such explanations, as they are often post hoc without much evidence that the story is actually a true description of causes.
“DSW: 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 … 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.”
Much more broadly, in human affairs in general, I side with Lewontin. We are story-telling animals, and we make up stories all the time – about our personal life, our social interactions, our politics – where we claim that certain events caused and therefore explain the current state of affairs. But I think the world is much more uncertain, and much more dependent on contingent events that are in essence unrelated to their consequences, than that. Everything does *** not *** happen for a reason – some things just happen.
Paraphrasing Lewontin, it is important to not invent “adaptive explanations” for everything that happens – we need to take all the stories we create to explain the world as a tentative combination of the facts as we think we know them and a whole bunch of internal habits, preconceptions, previous intellectual constructions, etc. Our desire to think we know why things happened as they did – to have a good story – shouldn’t override the realistic understanding that in fact we don’t know, or at least don’t know nearly as completely as we think we do. Or, paraphrasing Feynman, it is better to live with uncertainty than to believe things that are not true.
“
I was never comfortable with punctuated equilibrium as described by Gould in his popular writings, so it’s interesting and reassuring to see that even his classroom lectures on it were overstated.
Thanks, PZ. I’m going to keep the end of that first quote. It’s a good starting position for any investigation of human history, particularly ancient history.
David Sloan Wilson should certainly be able to recognise a huge ego when he sees one.
Evolutionary biologists have the best banter..