Friday, July 27, 2007

Review of Punctuated Equilibrium by Stephen Jay Gould

Biology's not my thing, really, but go ahead and ask Archaeopteryx about it, or even better, get him started about evolution denial. He's great at thrashing the idiots and it's fun to watch. Reading something along the lines of denial-bashing seemed like the fun angle for a reading selection, but I was disappointed to learn that what's the matter with Kansas doesn't really begin or end with wrongheadedness about evolution, but evidently falls under the usual broad, glib, partisan brush, and partial as I am to East Coast elitism, I don't really need to accentuate my biases.

So after striking out on my first choice for Arch, I decided to go straight, and chose Punctuated Equilibrium by Stephen Jay Gould. It makes a nice companion subject to the previous reading selection. I expected the world from this book, but left feeling that I could have done better for the best ornithologist I know.

I'm not at all sure who the intended audience for this book was supposed to be.* It seems too jargon-heavy and detailed for the omnivorous science reader, and too fluffy and personalized for a monograph. Most of the book is explaining ad infinitum the way in which the punctuated equilibrium model has affected the field, positively and negatively. If you want to call it something of a memoir and something of a rebuttal to his critics, then it succeeded on those levels.

Punctuated Equilibrium leaves the unfortunate impression that evolutionary biology is a science of words and not math. And (statistics aside) there may be something to that. If a physical or chemical principle is in dispute, you can go to the lab and construct experiments that can, in principle, confirm or deny the hypothesis. In paleontology, there are rarely extra data for the taking, and so instead it gets down to argument. Next to dropping enormous words with unforgivably compounded suffixes, examining researcher bias seems to be Gould's chief hobby horse. To hear him describe his field, it's a disappointingly lawyerly form of inquiry. Say it ain't so, Arch! I expected so much better from the most celebrated scientific writer of our times.

Punctuated equilibrium is only part theory. Gould identifies three legs of it: (1) the fossil record prevalently shows stasis of species accompanied with sudden changes, not the gradual transformation that Darwinism predicts, (2) species are proper evolutionary individuals, not (only) organisms, (3) that this explains the pattern of stasis and sudden change in the fossil record. These are Gould's descriptions by the way, though he acknowledges (at book length) that there is broad contribution (and criticism) that goes into the theory itself. Point 2 of his triad is the theory part. (1) is an observation, and (3) is a predicted result. I'd have been interested if he worked up a general mechanism for punctuation when it occurs, but it can almost be any old thing, and it may be many things. Gould mentions that some various researchers have demonstrated the third part of his theory in simulations, but he spends surprisingly little time on it. He spends more time describing how enhancing the debate is a validation of his ideas. I don't think it made for good reading.

I love the idea of species as individuals though. It seems right in teh context of my own way of looking at things, in which populations need to get pushed out of their stable states. I can think of several parallel and unrelated examples. In evolution, interbreeding is what locks that stability in, and in a way, same-species sexual preferences can be seen to preserve the species-individual (take that old man Darwin). I don't think Gould much approved of reasoning by analogy, by the way, but as a harper on researcher bias, he'd probably realize how we people tend to construct our models similarly, in a way that we can use the same language to describe different trends. Calling species out as Darwinian individuals, locked into stability by sexual compatibility, doesn’t seem so bold to me, and I'm comfortable enough with it in the above context. Like geology, the part that's hard to wrap a mind around is that even if speciation may approach human timescales, stasis is spread throughout the ridiculously long geological history of the earth. Speciation is a useful way to look at the quasi-individual at incomprehensible slowness--and Gould went far enough to address every counterargument he could think of on that one--and we talking apes are just fly-by observers of that long slow dance.

*much like this blog


Archaeopteryx said...

Sounds to me like biology is your thing. I haven't read Gould's book, but I'm somewhat familiar with the idea of the species-as-individual. I smiled when you said that Gould wasn't keen on reasoning-by-analogy--apparently you haven't spent much time reading his essays in Natural History (many of which were collected into anthologies). Gould was all about drawing parallels (sometimes extremely tenuous ones) between some facet of human culture and evolutionary theory.

It's quite the coincidence that I was lecturing my general biology class this very morning on this very subject. The whole punctuation-versus-gradualism flap seems overblown to me. We're arguing about whether speciation takes a very long time or, instead, a very, very long time. It seems to me that Eldredge and Gould make some excellent points, and that their detractors (notably Dennett and Dawkins) make some excellent points, and that there's no reason that they can't all be right. It's been pointed out by several authors that it's all but impossible to tell the difference between gradualism and punctuation in the fossil record, and some (Dawkins for one) say they're really just slightly different versions of the same thing anyway. In other words, you're in awfully good company by saying Gould's ideas here aren't so bold.

Not-so-incidentally, Gould is one of my favorite authors, and you were pretty much psychic in picking him as my entry in the books-for-buds program. I have The Structure of Evolutionary Theory (from which Punctuated Equilibrium was taken) on the pile on my night stand--now I'll have to move it to the top. Thanks for the review, and thanks for including me in the program.

However, I'm not letting that "best ornithologist I know" comment go to my head. I'm pretty sure I know how many ornithologists you know.

Artemesia said...

Don’t forget Barbara McClintock..and her ‘talking chromosomes’. She postulated genetic leaps
and ‘why/how’ they can occur. Not Darwin..not Gould and not the usual strict mechanistic approach.


this is more definitive:

When I read about her work, her combo of intuition and knowledge impressed me as gifted, and of one free to reason outside ‘the boxes’ of academic boundaries.

Keifus said...

Hi Arch. I thought for this book, he really had to first explain why he was writing it, why this was important in evolutionary theory. I didn't quite get how it was such a breakthrough as all that. Later in, he makes a point or two that we should be careful about too much reasoning by analogy, but you could tell he was tempted. It's too bad, because I just adore tenuous parallels. I think I would have loved those essays.

I'm glad I got you well with this one, though.

Artemesia, one speculation I had reading this was how such ephemeral stuff as knowledge and behavior can cause selective breeding, and as far as I know, speciation. If you think about it, it's easier to imagine a sea change in preference. We see it all the time. I guess I like to imagine that thinking somehow matters.

I'll have to check out those essays. (Later, though. Still not here.)