On The Origin of Species

This is part three of a three-part posting. Read part one and part two first.

It is just a few years since I read The Origin of Species by Charles Darwin. It was on my list of books that are so immensely famous that I must get around to reading them one day. Other books on the list that I’ve managed to get to are The Bible (extremely boring but I made it all the way through!), The Brothers Karamazov (very boring and full of right-wing religious opinions that rather spoilt it), Satanic Verses (amusing but what was all the fuss about?), and A Brief History of Time (quite dull, actually). Still on the list are The Koran, War and Peace, The Gulag Archipelago, Das Kapital and many, many others. So, when I finally got around to The Origin of Species, I wasn’t expecting much, something dull but worthy perhaps. After all, a scientific monologue from the 1850’s is hardly likely to be gripping, is it?

Boy was I wrong! The Origin of Species is without doubt the best piece of science writing I have ever read. It is extremely well-written, the argument is beautifully constructed and coherent and the level of detail and sheer quantity of evidence given to support the argument is awe-inspiring. The book is a tour de force, a superb example of how to construct and present an argument. And the material is so diverse, so fascinating and so clearly described that it held my attention from beginning to end.

The really puzzling thing is that anyone could get to the end of this book and not be convinced by it. What Darwin does is to lay out a very large number of examples of plant and animal physiology – each simple observations, so, I would have thought, irrefutable. Along with these, he presents his theory that the differences we can see between species is the result of an accumulation of changes which have occurred during reproduction and which have accumulated through inheritance. This mechanism of accumulating inherited changes is itself irrefutable, he believed – as anybody would who was aware of how animals and plants can be modified through selective breeding. He adds in the idea that, in nature, inherited differences will persevere in a breeding line according to whether the changes help or hinder the animal to survive in its environment and give birth to a new generation like itself. Which seems reasonable to the point of being a no-brainer. New species arise, he then claims, because changes may help those with the changes to colonise a new environment – somewhere where other members of the existing species cannot thrive – or because groups of individuals from one species are separated for long periods from one another and their gradually-accumulating changes make the individuals in each sufficiently different from those in the other.

So far, it is really hard to see how anybody could object to this theory. It is simple, it is logical and it explains all the known facts. Yet, just to make it as airtight as possible, Darwin methodically lists all the possible objections you might think of and addresses them, one by one. In doing so, he brings in evidence from geology and animal and plant husbandry, specific experiments he has devised and run to clarify key points, and so on. The pains he takes to address each and every possible difficulty that anyone might raise are impressive in themselves, as is the honesty with which he judges the adequacy of his evidence and his arguments.

I finished the book with a huge respect for Darwin and what he had achieved. The Origin of Species is rightly considered one of the greatest achievements of science. I now know it is perhaps the best single example of all that is good about the method. The Origin of Species is one huge and comprehensive argument in favour of accepting a particular explanation of a massive number of otherwise disparate facts. It works from data which any reasonable person would accept – the shapes of petals, the lengths of limbs – using only sound and clear argumentation to justify the acceptance of the theory of evolution by natural selection. It is, quite simply, a masterpiece, a work of which all of humankind should be enormously proud.

Yet it is this great achievement of the human intellect that religious fundamentalists want to tear down. And why? Not for any rational reason at all but because to accept this argument would mean that a literal interpretation of the Bible would be impossible. For people like this, we must also reject the theory that the stars are distant objects (otherwise the light from them would not have time to reach us because they were all created just a few thousand years ago!), the theory that deeper rocks are older than ones near the surface (because ‘geological time’ spans far too many years to be consistent with the Genesis myth), that there ever were dinosaurs, that the genetic similarity between ourselves and chimps – or amoeba for that matter – has any meaning at all, that the craters on the Moon are anything other than recent decoration, and so on and so on. All of this, all of the huge diversity and wonder of the Universe, all of the beautiful theories we have so painstakingly devised and tested over and over from cosmological to quantum scales, must be cast aside as obviously untrue because it contradicts the narrow, unimaginative, ignorant speculations (sorry, revelations) of some old world mystics?

Do me a favour!