Omnivolution

Transcript of a recent email discussion. On the heels of an afternoon discussion in the Modern that carried over to an evening in Korea town.

Aaron Lee highlighted a viewpoint published recently in the New Scientist:

"Over the aeons of evolutionary time, the interaction of these multiple constraints has produced many viable phenotypes, all compatible with survival and reproduction. Crucially, however, the evolutionary process in such cases is not driven by a struggle for survival and/or for reproduction. Pigs don't have wings, but that's not because winged pigs once lost out to wingless ones. And it's not because the pigs that lacked wings were more fertile than the pigs that had them. There never were any winged pigs because there's no place on pigs for the wings to go. This isn't environmental filtering, it's just physiological and developmental mechanics."

This hit a chord with Trevor and me, who have been lamenting the intellectual laziness of academic biologists and popular science writers, alike, who use the theory of evolution as a mindlessly applied coda and rationalization for everything from behavior to flower petals.

Trevor's reply:

LOVE IT. OMG LOVE IT.

Why, I hear you ask? Because the public discourse so desperately needs effective narratives in biology that point to something *other than* evolution as cause.

You know, normal people never got over teleology. Student of Aristotle: "Why does an acorn fall to the ground?" Aristotle: "Because of its inner potential, its arete. The acorn *wants to* fall towards the ground." Weird, yes. But notice, especially in biology: "Why does the heart beat?" "To pump blood."

Really?

Really to pump blood?

Whatever else is going on, the heart beats in response to nervous impulse originating from multiple other sites in the body. But then this is frustrating: turtles, all the way down.

SO INSTEAD, the New York Times, among others, have decided that the answer to literally every question in science reporting -- especially reporting on issues in biology -- is due to evolution, by which they mean (and understand) only selection pressure, to the exclusion of all the other factors of macroevolution that could matter. Why does the heart beat? Because a beating heart was *evolutionarily advantageous*. (It works even better if an already-formed image of humans hunting or mating can be pulled into the picture because popular discussion of evolution always everywhere takes place against a silent cartoon backdrop at the level of the Flintstones: well, you see, long quadraceps meant that man was able to run faster to kill prey, and that's why their evolutionary adapted; or if not for running, then to hunt down women and pass on his genes.)

Grrr.

First, it's a danger to understand evolution as a (19th-century) narrative of individuals. Evolution doesn't care about the narrativity (or not) of individuals; it cares about the sum genetic material lodged in *POPULATIONS*.

Second, the reason a lot of shit exists in the world is because a lot of shit is possible to *grow from patterns* ... patterns that, in probably most cases, haven't ever been the subject of selection pressures. The difference between a 2-, 3- or 4-chambered heart probably has, indeed, been the target of millions of years of selection pressure. But finding of every result in neurobiology (or dietary genetics, or human locomotion, and on and on) shouldn't always everywhere -- and unreflectingly -- be assumed the result of selection pressure.

* * *

Which is why I like the quote above.

:)

And mine:

Aaron, as you can see, you touched upon one of Trevor and my "pet topics." My favorite part of the article is when they broke from the scholarly tone to be angry:

"However, the internal evidence to back this imperialistic selectionism strikes us as very thin. Its credibility depends largely on the reflected glamour of natural selection which biology proper is said to legitimise. Accordingly, if natural selection disappears from biology, its offshoots in other fields seem likely to disappear as well. This is an outcome much to be desired since, more often than not, these offshoots have proved to be not just post hoc but ad hoc, crude, reductionist, scientistic rather than scientific, shamelessly self-congratulatory, and so wanting in detail that they are bound to accommodate the data, however that data may turn out. So it really does matter whether natural selection is true."

---

Having said that, I have to take a step back and be critical of the authors. Of most significance: Darwin was the first to point out the limitations and potential pitfalls of his theories. So, I tend to be annoyed with the Darwin deists as much as I am with his detractors. Like with all good religions: NO ONE ACTUALLY READS DARWIN. At least not anymore. That is why I have made a habit of working my way slowly through his writings.

I prepared a lecture for my colleagues in Cambridge on this topic and also on why Lamarck wasn't as silly as BIO 101 course books make him out to be. In fact, Darwin had read and respected many of Lamarck's original thoughts on evolution, namely soft inheritance: that heritable changes can occur during the lifetime of an organism, not just during the transition for organism to organism. It isn't as simple as giraffes and tall trees, but it is still compelling and an important part of the puzzle for understanding inheritance and evolution. The plan can change mid-stream, and that can be inherited.