Anglican Samizdat

February 6, 2010

A valuable onslaught on neo-Darwinist simplicities

Filed under: evolution — David @ 11:08 am
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A poke in the eye to atheist fundamentalism à la Dawkins:

Charles Darwin complained quite crossly in his autobiography that, despite many denials, people still kept saying he thought natural selection was the sole cause of evolutionary development. “Great is the force of misrepresentation,” he grumbled. Had he known that, a century later, his alleged followers would be promoting that very doctrine as central to his teaching, and extending it into the wilder reaches of psychology and physics, he might have got even crosser. Darwin’s objection was surely not just that he could see other possible causes. He saw that the doctrine itself did not make sense. No filter, however powerful, can be the only cause of what flows out of it. Questions about what comes into that filter have to be just as important. The proposed solution bears no proportion to the size of the problem.

Since his time, biologists have discovered a huge amount that is really interesting and important about internal factors in organisms that affect reproduction. This powerful little book uses that material to challenge sharply the whole neo-Darwinist orthodoxy – the assumption that, essentially, all evolution is due to mutation and selection. Its authors do not, of course, deny that this kind of classical natural selection happens. But they argue strongly that there is now no reason to privilege it over a crowd of other possible causes. Not only are most mutations known to be destructive but the material of inheritance itself has turned out to be far more complex, and to provide a much wider repertoire of untapped possibilities, than used to be thought. To an impressive extent, organisms provide the materials for changes in their own future. As the authors put it, “Before any phenotype can be, so to speak, ‘offered’ to selection by the environment, a host of internal constraints have to be satisfied.” Epigenetic effects, resulting from different expressions of the same genes, can make a huge difference. And genes themselves are now known not to be independent, bean-like items connected to particular transmitted traits, but aspects of a most intricate process, sensitive to all sorts of internal factors, so that in many ways the same genes can result in a different creature. Recent work in “evodevo” – evolutionary developmental biology – shows how paths of development can themselves change and can change the resulting organism. And again, forces such as “molecular drive”, which ­rearrange the genes, can also have that effect.

Besides this – perhaps even more interestingly – the laws of physics and chemistry themselves take a hand in the developmental process. Matter itself behaves in characteristic ways which are distinctly non-random. Many natural patterns, such as the arrangement of buds on a stem, accord with the series of Fibonacci numbers, and Fibonacci spirals are also observed in spiral nebulae. There are, moreover, no flying pigs, on account of the way in which bones arrange themselves. I am pleased to see that Fodor and ­Piattelli Palmarini introduce these facts in a chapter headed “The Return of the Laws of Form” and connect them with the names of D’Arcy Thompson, Conrad Waddington and Ilya Prigogine. Though they don’t actually mention Goethe, that reference still rightly picks up an important, genuinely scientific strand of investigation which was for some time oddly eclipsed by neo-Darwinist fascination with the drama of randomness and the illusory seductions of simplicity.

This book is, of course, fighting stuff, sure to be contested by those at whom it is aimed. On the face of things, however, it strikes an outsider as an overdue and valuable onslaught on neo-Darwinist simplicities.

As this article notes “no filter, however powerful, can be the only cause of what flows out of it.” Christians have always known the force that drives the filter: God.

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