Wednesday, September 19, 2007

Evolution: misconceiving change

Your average Harry Potter book is full of mystery, myriad unusual details, and engaging narrative. And it gets better with each book. There's the recent finale, then the series ends.
And while there's a steady flow of ideas, there are few strong insights – except towards the end, and even those are already out there, in the “published literature”, so to speak.

Stephen Jay Gould's volumes of essays are similarly laden with mystery, a welter of odd details, and reader-friendly narratives. But in contrast to Rowling, each essay yields new insights that can, sooner or later, be applied in a much wider context. And although death brought closure to Gould as to all, the extant series provides years of thought-provoking enjoyment, and doesn't close off the story of evolution, science and knowledge.

Punctuated equilibrium writes nature's primary signature” - SJG

The following example is yet another illustration of a popular misconception of evolution.
I started his essay 'Cordelia's dilemma' in Dinosaur In A Haystack (1996, Jonathan Cape). It was a tale of nothing, as was Cordelia's response to Lear... but there are lessons in nothing.

Gould begins with the publication bias of scientific research: that journals tend to publish papers with positive results, i.e. those with a story to tell. Studies yielding negative results (eg “we've found no correlation between these factors”) far more often suffer from a) languishing unpublished; b) languishing unsubmitted for publication.

After a few illustrations, Could moves to the concept that originally made his name: Punctuated Equilibrium, that is, most species exhibit little change over the course of their existence, and actual change is relatively rapid in geological time scales.

Most of the time: no change. This narrative had been largely overlooked by paleontologists as either not carrying any narrrative, or not exactly fitting in with evolutionary thought. Gould's own thesis supervisor spent a good deal of effort on statistical analysis of brachiopod evolution to no apparent avail, before switching disciplines.

The wider misconception is, again, anthropocentric. On a human scale, we see constant change throughout history – change is the constant, the mantra runs. When it's not revolutionary, it's said to be “evolutionary” - that is, gradual. But that's the mistake: evolution is not, on the wider scale, gradual and steady. It's rather closer to our concept of “revolution”. That is not to say instantaneous and all-encompassing at all – at least in our measure. Thousands of generations is not instantaneous to us, and yet again it is, to Earth's time scale. Apart from those flashes, the narrative flatlines for much, much longer.

In capitalist economics, fluctuation is the norm, and equilbrium a mere blink. In evolutionary history, it's the other way around.

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