Reality Conditions

Sunday, April 02, 2006

Not quite a book review of A Devil's Chaplain, by Richard Dawkins

I started to write a book review of this book for posting it, but when I picked it up to refresh some details I was startled to see that I haven't really finished it! It is a collection of 32 essays and articles, and I have been reading them in disorder, so it's not so weird that I could think I had read them all and realize now I am still missing a few. Or well, perhaps it is. Anyway, that's what happened, but I will still write a post on a few isolated facts I learnt from the book that I found interesting or even thrilling:

- There are in Britain two well-differentiated species of gulls, with different colours and no interbreeding, but such that if you take one of them and track it round the world through North America, Alaska and Siberia, at each point round the way it is only one species, but it changes its colour gradually and when you are back in Britain it is the other species! The possibility of these "ring species" should not be a surprise for those who have absorbed the anti-essentialistic message of Darwin, but I had never thought of the possibility and was thrilled by reading about it.

- Darwin came tantalizingly close to completing his theory with the discoveries in genetics usually attributed to Mendel. He wrote to Wallace: "I crossed the Painted Lady and Purple sweet peas, which are very differently coloured varieties, and got, even out of the same pod, both varieties perfect but none intermediate". He is knocking at the doors of genes as discrete heredity units here.

- A quote Dawkins makes from a zoology book that creates an eerie image: "If all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable ... we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes ... Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficent knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasits."

- Dawkins was an excellent personal friend of Douglas Adams, as well as a huge fan of his books.

- Though he created the concept, Dawkins is not quite as enthusiastic on "memes" as some of his succesors, in particular Dennett, have been. He is delighted that they have taken up his suggestion, but does not commit himself to endorse any of the particular uses "meme theorists" have made of it. He put forward the idea of memes just as a cultural analogue of genes on which a kind of Darwinian selction also acts, but wasn't intending them to play a founding role in theories of human mind or culture.

- Claude Shannon, father of information theory, had a strange sense of humour that led him to construct an "Ultimate Machine" that Arthur C. Clarke described in the following way: "Nothing could be simpler. It is merely a small wooden casket, the size and shape of a cigar box, with a single switch on one face. When you throw the switch, there is an angry, purposeful buzzing. The lid slowly rises, and from beneath it emerges a hand. The hand reaches down, turns the switch off and retreats into the box. With the finality of a closing coffin, the lid snaps shut, the buzzing ceases and peace reigns once more. The psychological effect, if you do not know what to expect, is devastating. There is something unspeakably sinister about a machine that does nothing -- absolutely nothing -- except switch itself off."

- When Stephen Jay Gould died, he had pending for revision a letter to the New York Review of Books that Dawkins had written for them to sign jointly, denouncing creationism and explaining why scientists should not debate with creationists in an academic context like a university (it gives them the respectability they are searching for and gives the public the impression that there is a real "scientific controversy" going on). Despite their known disagreement on many matters concerning evolution, Gould and Dawkins were firmly on agreement on this matter.

- And finally, the most exciting thing I read in the book. Dawkins makes the deduction from Moore's Law that the increase in DNA sequencing power grows exponentially (because it is driven mainly by computer processing capacity). Extrapolating this, he concludes that by the year 2050 we should be able to seqence a complete human genome for a trivial cost of £100. The same would be true of course for any animal species. By comparing the full genomes of humans and chimpanzees, we should be able to reconstruct the genome of the antecessor we share with them, that lived 5 to 8 million years ago. Comparing in turn this genome with ours, we may be able to recreate the genome of an intermediate species between us and the common ancestor -perhaps an Australopithecus. And if we have its genome, we may be able to bring the creature itself back to life...
The same game can be played with birds. Birds descend from dinosaurs that descend from ancient reptiles from which also modern reptiles are descended. Comparing the genome of birds and of modern reptiles might give us the possibility of reconstructing their last common ancestor, and afterwards an intermediate stage between it and a modern bird... in other words, a DINOSAUR!!
So even if the exact plot of Jurassic Park is impossible because no DNA is preserved in amber fossils and there is no original dinosaur DNA left in the world now, by intelligent examination of the DNA of the modern grandsons and second cousins of dinosaurs we may be able to reconstruct it and bring them back to life anyway. May that happen in our lifetime, amen!


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