(The third part in a series celebrating Charles Darwin: Part-1, Part-2)
Excerpts
Charles Darwin was a giant. He did not merely write “On the Origin of Species” — one of the most important books ever written by anyone — in which he describes how evolution by natural selection works, and what some of its consequences and implications are. He also wrote — and this list is not exhaustive— a treatise on the formation of coral reefs that is still thought to be correct; a definitive monograph on barnacles, both extinct and extant; a book about how earthworms make soil; a now-classic text on carnivorous plants (the ones, like Venus fly-traps, that ensnare and digest insects); a book about the strange ways that orchids get themselves fertilized; and an account of the five years he spent aboard the ship HMS Beagle, which has become a classic of travel writing.
As if that wasn’t enough, he proposed sexual selection — the idea that decorations and ornaments, like peacocks’ tails, evolve because females in many species prefer to mate with the most beautiful males. Sexual selection has since become a major field of research in its own right.
In short, Darwin did more in one lifetime than most of us could hope to accomplish in two. But his giantism has had an odd and problematic consequence. It’s a tendency for everyone to refer back to him. “Why Darwin was wrong about X”; “Was Darwin wrong about Y?”; “What Darwin didn’t know about Z” — these are common headlines in newspapers and magazines, in both the biological and the general literature. Then there are the words: Darwinism (sometimes used with the prefix “neo”), Darwinist (ditto), Darwinian.
Why is this a problem? Because it’s all grossly misleading. It suggests that Darwin was the beginning and the end, the alpha and omega, of evolutionary biology, and that the subject hasn’t changed much in the 149 years since the publication of the “Origin.”
He wasn’t, and it has. Although several of his ideas — natural and sexual selection among them — remain cornerstones of modern evolutionary biology, the field as a whole has been transformed. If we were to go back in a time machine and fetch him to the present day, he’d find much of evolutionary biology unintelligible — at least until he’d had time to study genetics, statistics and computer science.
Oh, there would be so much to tell him! A full list would take me weeks to write out. But the obvious place to begin would be the discoveries of genetics, especially DNA. We’d have to explain that cells in each organism contain a code describing how to build that organism, written in chemical form — DNA — that evolutionary forces are constantly rewriting. Indeed, the study of DNA allows us to see the action of natural selection on a molecule-by-molecule basis. We can see the genes where natural selection acts to prevent evolutionary change, those where it drives change and those where it has no effect at all.
-----
What would he make of it all?
I think his reaction would be a mix of satisfaction and astonishment. Satisfaction: that natural selection has turned out to be such a powerful idea, explaining such a wide range of phenomena. Astonishment: for the same reason. He would, I think, be fascinated by the weird natural history that has been discovered in the past 150 years — such as Wolbachia, bacteria that pervert the reproduction of insects for their own ends. (Wolbachia can have a number of effects, but one of the most common is to kill all a female’s sons. The reason is that sons don’t transmit Wolbachia, so from Wolbachia’s point of view, they are a waste of space.) I’m not sure he’d enjoy analyzing DNA sequences — he might find it a bit too abstracted from the living organism — but I think he’d be delighted to learn the results. I think he would be shocked by how much we know about the so-called model organisms — worms, toads, fruit flies, mice, humans and the bacterium E. Coli — and how little we know about everything else. And I think he’d be startled by the nature of scientific research — the scale of the enterprise, the cost, the pressures to publish and the degree of specialization that results. His brand of science — 20 years of thinking about a problem before publishing — could not be done today.
Note at the top, that this article is from a series in the New York Times. Readers may be interested in reading the whole series, including the rest of this article.
No comments:
Post a Comment