Monday, July 26, 2010

317. Some Thoughts on Evolution, Natural and Cultural: 1

James Le Fanu's recently published book, Why Us? How Science Rediscovered the Mystery of Ourselves, raises some issues regarding Darwinian evolution to which I feel compelled to respond. My compulsion might seem a bit odd, since the topics I've been covering on this blog are only tangentially related to Darwin, and I doubt there is anything in Le Fanu's book with a direct bearing on any of the ideas I've expressed here. But some of the things he writes about have triggered thoughts that might prove relevant down the line. So here goes:

The first thing to say is that Le Fanu writes reasonably well, his book is unusually engaging and, up to a point, I found myself learning from it. He is out to "debunk" Darwin and the principle of natural selection, but where he differs from most such skeptics is in his awareness of some of the most recent research, especially in the areas of molecular science and cognition. Not that he neglects some of the most notorious old, "tried and true" objections, such as the "impossibility" of such a complex organ as the eye being produced via such an essentially random process as natural selection:

Each different type of eye compounds Darwin's difficulty further, for then it is necessary to presuppose for each a series of fortuitious 'numerous successive slight modificaitions,' conferring some slight biological advantage to its possessor. It is necessary to presuppose, for, despite much effort, there is not a single empirical discovery in the past 150 years that has substantiated Darwin's proposal that natural selection . . . explains the 'puzzle of perfection' epitomized by so many different types of eye -- which remains yet more puzzling than it was in 1859 (p. 95).
In fact there has been at least one "empirical discovery" that goes a long way in helping us understand puzzles such as the development of the eye, but I won't get into that as yet. Le Fanu raises a great many objections on a similar level, none of which are new, and all of which can be easily explained by those with a background (which Le Fanu lacks) in biological science. Since I too lack such a background, I'll be referring you, from time to time, to a definitive source, by an outstanding authority on the topic: What Evolution Is, by Ernst Mayr.

Another example of a well worn objection to Darwin's thinking is worth getting into here because it involves a difficulty still little understood, even by many of Darwin's supporters: the many "gaps" in the fossil record. Along with the "puzzle of perfection" exemplified in the development of the eye, Le Fanu cites, as the second of the "two most uncomfortable difficulties of Darwin's evolutionary theory, . . . the lack of evidence in the fossil record for the 'inconceivably great' number of transitional fossils required by a process of gradualist evolutionary transformation" (p. 117).

Darwin had argued that only the most gradual transitions could account for the many distinctions we see, on so many levels, among virtually all living things, in both the present and the past. Yet he was forced to admit that the fossil record contained a great many very significant gaps, which he could account for only by noting the paucity of the fossil evidence available in his day. Le Fanu reminds us of all the many years that have passed since Darwin's time, during which only a fraction of the needed fossil evidence has been filled in. Huge gaps remain, and there is very little reason to suppose that any of them will be filled in the manner anticipated by Darwin.

(to be continued)

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