Richard Dawkins

UNWEAVING THE RAINBOW

Science, delusion and the appetite for wonder

The title of this book comes from Keats, who believed that Newton had removed the magic from the rainbow by explaining its colours scientifically. Dawkins argues, persuasively in my view, that Keats had it precisely wrong. But this view of science was quite common in the nineteenth century (William Blake was a prominent exponent) and it is if anything gaining ground today.

Dawkins makes a good job here of showing such views to be the nonsense they are. Written with his usual clarity and elegance, the book looks at how knowledge of the way things work in nature is truly a source of wonder. The tone is nicely judged—never ranting or aggressive—and there are plenty of well-chosen quotations that make the case neatly from within the literary world itself.

Dawkins looks first at the eponymous rainbow, starting with the physics of light and going on to discuss colour vision. Light can be thought of as a form of vibration, and so can sound, which is the subject of the next chapter. Dawkins applies the metaphor of barcodes to both of these, and it can also be used to refer to DNA, which is treat in another chapter.

Dawkins is well-known for his hostility to bogus claims for the paranormal, and there are chapters on this and on why it is that people are so easily deceived into believing in the unreal. This leads into the subject of apparent coincidences and the difficulty which most of us experience in forming correct intuitions about probability.

I thought the later chapters in the book were the most interesting. I liked the discussion of what Dawkins calls bad poetic science. Stephen Jay Gould figures largely here as an exemplar of the genre (he and Dawkins were often at loggerheads). The topics in dispute include the significance of discontinuities in the fossil record and differences of interpretation of the "Cambrian explosion". Dawkins says that there must logically have been creatures prior to the Cambrian that didn't fossilize, and these may go far back in time before the Cambrian. But the notion of an "explosion" persists. "Doubtless it has great poetic appeal."

Two chapters are about genes as selfish replicators, and here there is again (fairly gentle) debunking of bad poetic science. One example is the claim that we should take the peaceable and sex-mad bonobo as a role model instead of the more aggressive common chimpanzee. The whole idea of using animals as role models is fundamentally wrong, Dawkins believes.

Another cited example of bad poetic science is James Lovelock's "Gaia" hypothesis. "[T]he whole rhetoric of Gaia is superfluous and misleading. You don't need to talk about bacteria working for the good of anything other than their own short-term genetic good." I'm not sure that he is entirely fair to Lovelock here, but there is no doubt that the Gaia idea has spawned a huge amount of sentimentality and bogus science in other quarters.

The book concludes with a chapter looking at the perennial mystery of the evolution of the human brain. What drove this dramatic development? We don't know the answer, but Dawkins has a stimulating discussion. The invention of language is his favourite candidate for what may have driven the expansion of our brain, and I was particularly pleased to find that he refers here to one of the most fruitful ideas I have seen, namely Terrence Deacon's meme-like approach to the evolution of language as described in his book The Symbolic Species