ABSTRACT
One of the charms of coming with a Darwinian eye to the study of organisms is recognizing the mixture they display of astonishing adaptive sophistication and botched improvisation. For a long time one of the most persuasive arguments for the existence of God was the so-called Argument from Design: the idea that the finely tuned structures of organisms simply could not have come into existence by chance, and must therefore be evidence for the existence of an unimaginably powerful and intelligent creator. Once Darwin’s theory of evolution by natural selection had proposed a mechanism by which such structures might result from purely natural and unplanned processes, what increasingly impressed biologists was the extent to which organisms turned out – despite being miracles of coordination and functioning – to be riddled with absurdities that no self-respecting designer would have allowed as far as the drawing board. Darwinian evolution does not work by planning from scratch with some end in view. The organisms produced by natural selection are merely the ones that happen to keep reproducing in the environments where they happen to be, and selection has nothing to work on but chance variations in structures that have previously been selected, often for quite different purposes. The result is that organisms carry with them fossils of their design history – which is why there has been so much success in tracing that history.
