Tuesday, September 18, 2012

Responses and Reactions to Threatened Paradigms

There have been a few responses to Dupré's column on a crisis in Evolutionary Theory; Dr. Jerry Coyne's and Dr. Massimo Pigliucci's.

Coyne's arguement

I think Dr. Coyne's argument would be seen by many as the standard fare to expect from most researchers on this issue. A crisis is an extraordinary thing, and it requires, so the saying goes, extraordinary evidence to support it. Dr. Dupré instead offers some interesting things that perhaps Ernst Mayr would've found really surprising, but not an Kuhnian indictment of Evolutionary Theory. 
Dr. Coyne's main beef is that we tend to hear the evolution is in crisis from a lot of quarters, and they're usually wrong. This is not to say that there aren't any debates between biologists, just that we aren't in the stagnation followed by revolution stage of Kuhn, nor near it.

Pigliucci's Points

Dr. Pigliucci's essay is as much a response to Coyne as it is to Dupré. Some would argue that a mainstay of philosophy is to use reconciliation between opposing camps to better get at the 'truth' of any particular matter, and that is what Pigliucci attempts here.

A major disagreement between Coyne and Pigliucci is over rare events and important events. Obviously an event can be both, and Pigliucci cites the Big Bang as a good example of just that. However, while Inflationary Theory is important, did it result in a re-writing of the Standard Model in Physics? While Margulis hit on something amazing in biology, does the endo-symbiont hypothesis really challenge the Modern Synthesis?

Another contentious point is the importance of 'causal arrows' that don't extend out of the genome. I don't think most would consider Coyne a genetic determinist, certainly not in the way that Dawkin's is usually accused of being, but he does seem fairly set in the idea that most of the important stuff traces back to the genome, and things that don't are just ancillary, not revolutionary.

This entire argument really tracks back to, or at least mimics in some ways, reactions to Kuhn's Structure of Scientific Revolutions (pdf). Many felt that what Kuhn was describing was the way science normally operates, that he hadn't hit on anything really interesting, and for others his shifting paradigms concept was a truly revolutionary way of understanding change in science, of addressing the 'problem of progress'. For the people who felt Kuhn wasn't saying anything new, well, it was just that, he was describing things events that were already well known, understood, and accepted. His small problems that a standing theory couldn't address (and that eventually were involved in the theory's downfall), weren't capable of bringing the theories down (in this contra-Kuhnian line of thinking). The small problems were relegated to the side or worked on further in the normal process of science, and only added to the existing theory. Thus it is with Dr. Coyne's assessment of Dr. Dupré's crisis claim, the small issues are just that, small, and while they're real, and affect evolutionary theory, they don't represent a crisis.
Prof. Pigliucci seems to feel differently, even if he isn't happy with Dupré's use of 'radical' to describe the changes, and he rattles off a list of concepts that are foreign to the Modern Synthesis.


The biggest challenge to the Modern Synthesis, in my mind, was Genetic Drift and Neutralism, even tho some might argue that they're 'fully' accounted for in MS. And they were successful challenges, and they defeated the Modern Synthesis, or at least the MS-based claim that they couldn't contribute to an organism's evolution and history. But the MS was formulated around a hundred years ago; I don't think that Dr. Coyne is trying to defend the traditional MS in this piece. Dr. Dupré explicitly mentions the MS, and his 'threats' are threats to the MS, but haven't we moved away from the MS already anyway? That's been my impression for a while now, so while Dupré would certainly be right that the traditional Modern Synthesis, which is pretty explicit about what counts in Biology, is challenged to the point of crisis (Kuhnian or not) by the 'threats', or rather, it already had been challenged by those threats and had to give in to them.

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