The Undesigned Tree of Life

Dawkins draws his title from the writings of the 18th century philosopher William Paley, who made the argument that just as one can see conscious design in the specialization and complexity of a pocket watch--a complicated bit of machinery for his day--one can also see the workings of a creator in the complexities of nature. It is Dawkins' contention that this is not so, particularly with respect to the living world. Evolution by natural selection can, through small, single-step changes, account not only for the development of complex organisms, but also the wide variety of organisms past and present.

Early in the book, he discusses echolocation among animals, particularly bats. His detailed description of what it is, the differences between species of bats I found intriguing in itself, apart from point he was trying to make with respect to the development of this ability through natural selection. Bats are not my thing, to be honest. If I were to find one in my house, I'd certainly do my utmost to make it leave as quickly as possible. Nevertheless, Dawkins' chapter about them did make for good reading.

His main point, that is, that evolution through natural selection accounts for the complexities of living organisms, is illustrated with a computer program he wrote that incorporates both random mutations and selection in creating visual patterns. The selection is done by the operator from basic branch shape, which then branches again according to the random mutation of 9 different components ("genes"). Suppose the operator is looking for something like a bug. S/he would select whatever patterns appear to be the most bug-like, subject them to another branching involving random change, and select again from the patterns that were next offered.

Using these steps, Dawkins is able to create patterns that resemble bugs, lunar landers, lamps, bats, any number of things in as few as 29 "generations." Expecting no more than variations of trees, he is surprised, indeed, elated, at what the program comes up with, hearing Also Sprach Zarathustra in his mind and to sleep dreaming of his bug-creations.

But he is not so self-absorbed to believe that a computer program, however cool it is, is actually empirical evidence supporting the theory of evolution. There are chapters on genetics, DNA, convergent evolution, and taxonomy and the surprising heat the last can generate among biologists. There is also a speculative discussion on ideas regarding the origin of life (abiogenesis), a debate in which Dawkins clearly delights but demurs picking a favorite. Near the end of the book, he has a chapter taking to task the idea of punctuated equilibrium, that is, that organisms go through long periods of little or no evolutionary change followed by rapid (geologically speaking, that is) change in response to changing environmental pressures. The final chapter is dedicated to some ideas that may be considered rivals to the theory of evolution by their adherents, but which Dawkins claims lack the explaining power--both in depth and breadth--the the theory of evolution does.

While the book is not an attack on creationism per se, Dawkins does mention a few of their ideas, mostly in passing and mostly with withering contempt. His book is an attempt to educate the public as to what evolution is and is not, for he sees a great deal of ignorance among the public, particularly in the US, regarding evolution. In a story he mentions in the introduction 1996 edition (and repeated later in the main text), he talks about doing some radio phone-in shows in the US. He says he was warned to expect some hostile comments from fundamentalists and confesses that he was looking forward to ripping their arguments apart.

"What actually happened was even better. The listeners who telephoned were genuinely interested in the subject of evolution. They were not hostile to it, they simply did not know anything about it. Instead of destroying arguments, I had the more constructive task of educating the innocent." (p. xi)

This is probably what got me started feeling uneasy. I don't wish to overemphasize the point, because he does present a lot of good information with abundant metaphors, illustrations, parodies and analogies. Nevertheless, I got the uncomfortable feeling that Professor Dawkins was explaining himself v-e-r-y s-l-o-w-l-y for the sake of the kids in the back of the room (the Americans?). While a minor point, it made my reading of the book take longer than it normally would have. I will probably return to this book in the future for reference or to refresh my memory on certain points, though. It was definitely worth the effort, informative and interesting.

Also reviewed:
Unweaving the Rainbow
http://www.epinions.com/content_8926498436/tk_~CB003.1.74