Epilogue

After careful reflection, I'd say it is worth reading The Origin of Species. Biology doesn't erase it's past, as I thought. It just forgets to cite it.

The Origin is biology's hub -- all the routes that the science has taken since seem to pass through it. This, I think, is partly because Darwin had such a complete vision of the living world, and partly because his ignorance of some areas was so great that he had to hedge his bets, and mention everything in just in case.

The book is so rich that I could have written about entirely different subjects in each post.

To give just one example, in the chapter on natural selection, Darwin says this:

"We have reason to believe ... that a change in the conditions of life, by specially acting on the reproductive system, causes or increases variability; and in the foregoing case the conditions of life are supposed to have undergone a change, and this would manifestly be favourable to natural selection, by giving a better chance of profitable variations occurring[.]"

This is now called evolvability; it's the ever-controversial idea that organisms can produce variation to order, and even that this variation can take an adaptive form, and there's a lot to be said about it.

The weight of evidence that Darwin gathered, and his use of verbal rather than mathematical arguments, can obscure what a brilliant thinker he was. I don't think he's a plodder at all, I think he's up there with Einstein in his ability to see the world's hidden dimensions and underlying processes.

Throughout the book, you can feel Darwin building a model of nature in his head and tinkering with it. The lengthy passage in the chapter on natural selection where he gives a theoretical discussion of diversification and modification is a slog to read, but it's also a thrill to feel Darwin peering through time, winding it backwards and forwards and seeing his laws shape the species in his imagined world.

In the chapters on geographical distribution, he does the same thing for the real world, like someone looking at a chessboard midway through a game and working out every move up to that point. Couple that with his ability as an experimenter -- in the breeding studies of pigeons, and on seed dispersal -- and I'd say he's in a biological league of his own. (He was, of course, lucky that biology was unformed and unspecialized; it's difficult to imagine anyone making a similar impact today.)

Darwin's breadth means that within the Origin, you can see all the strands that currently comprise evolutionary thought, and often come into conflict. I mentioned how clearly Darwin could see evolution's logical core in the previous post, and I've mentioned that I think he thought natural selection on variation in individuals by far the most important force in evolution.

Here you can see the roots of what I think of as the lean'n'mean school of evolutionary biology -- that line of (mostly) skinny Englishmen running through Ronald Fisher, William Hamilton and John Maynard Smith whose evolutionary ideas tend to be simple (even austere), mathematical, and whose first thought is to look for an adaptive argument behind a biological trait.

(Marek Kohn gives an accessible guide to this tradition in 'A Reason for Everything'; as a leading contemporary member of this strand, I'd nominate Alan Grafen, who isn't English, but who is working to provide the equations that Darwin lacked in his 'formal Darwinism' project.)

On the other hand, Darwin -- because he was a fantastic naturalist -- also sees the complexity and variability of the natural world. He admits other forces besides natural selection, and, of course, left lots of questions unanswered.

Here you can see why those who take a 'Let a thousand flowers bloom' view of evolution, seeing it as the consequence of many forces acting at various levels, such as Stephen Jay Gould, are also his descendents.

The Origin presents evolution as a sleek, hard white monolith surrounded by elaborate ornamentation. Those who came after Darwin disagree over whether they find the monolith or the ornamentation most beautiful and significant, and whether the ornamentation is scaffolding that was useful in getting the monolith up but is no longer needed, or whether it's an integral part of the whole structure.

This isn't to say that anyone is stupid enough to do biology today by asking 'what did Darwin think?' Rather, it's that reading the Origin has enhanced my understanding of the themes and currents in contemporary biology, in the same way that knowing a little about the Bible and classical mythology helps you read a renaissance painting.

The Origin is also, of course, of its time. I thought that Darwin's mention of the woodpecker in his introduction was original and daring, until David B commented that in Natural Theology William Paley held the bird up as a prime example of the creator's handiwork.

This made me realize that, from where I'm looking, it can be difficult to know what prompted Darwin to take a particular example, or what he was hoping to prove or disprove in a particular argument (a richly tagged and linked online version would be a big help here). He's writing to his contemporaries, not us -- which makes it more impressive that so much of the book seems so current.

And the Origin, although often well written, isn't uniformly page-turning. Darwin was writing to convince more than to entertain, and that led him to assemble his arguments in a more measured and exhaustive way than someone writing popsci would.

If you're in a hurry, my highlights are the chapters on the Struggle for Existence, Difficulties on Theory, Instinct, the two on Geographical Distribution (minus the section on glaciation) and the Recapitulation and Conclusion. The ones I think could be most safely skimmed or skipped are those on the Laws of Variation and Hybridism (there's a few hours I'll not get back). That partly reflects my background in ecology and behaviour. If you're into paleontology or development, your Origin will be different.

Reading quickly helps, I think, as it immerses you in Darwin's argument and writing style, and helps keep up momentum.

And blogging helps immensely -- if you have to think up things to say about a book, it means you can't afford to get too bored (which may have distorted my experience relative to another reader). One of the things that's made this such an enjoyable gig for me is that it's made Darwin's work seem new and up-for-grabs, not a sacred text chiselled on stone tablets. And that's how science should be.

That's enough from me. Thanks to everyone who's commented so far. Don't go quiet on me now.