Wright and the Synthesis

Sewall Wright and Evolutionary Biology (Science and Its Conceptual Foundations series)

by William B. Provine

This is a superb history both of Sewall Wright and of the emergence of the neo-Darwinian synthesis, although, being an intellectual biography of Wright, it is not a complete picture of the development of that synthesis. Although I am critical of Darwinism, the fact remains that this is a compelling subject, if only the hype factor were subtracted from later accounts that make the mathematical version of post-Darwinism appear like the triumphs of physics. That is definitely misleading. Starting out biographically, the second half of the book details the complex history of evolutonary theory as it appeared in the twenties, thirties and forties, at the hands of Wright, Haldane, and Fisher. That the 'synthesis' was really a two or three headed beast, and that Fisher and Wright had a falling out and produced different versions of basic theory is not always obvious from the slick texts on population genetics now promoting what seems like a finished subject. The issue of genetic drift, from Wright's early ideas, consistently misprotraryed, to the contribution of Kimura, is especially valuable. I was dumbfounded to learn that Provine, in his discussions with Wright as he researched his book, finds the ubiquitous use of fitness landscape graphs to be incoherent! The account makes clear just how difficult it is to produce a theory of evolution, and the overconfidence of promoters proceeds in apparent ignorance of what's going on in their subject, so soon rendered over into a packaged paradigm by Dobzhansky et al. Quite apart from anything else, Wright insisted on the complex interactions of gene complexes, and yet his and Fisher's work proceeds with the standard (over-)simplifications of very restricted subsets and loci. The complexities remain undiscovered country and were present from the beginning, starting with Moritz Wagner of the 1870's with his observations about non-adapative speciation. Peter Bowler in The Eclipse of Darwinism describes the state of evolutionary theory at the beginning of the twentieth century, the world of Bateson, De Vries, and Morgan. This is the context of Sewall Wright's gestating contribution to the marriage of Mendelism and the selectionism of Darwin. With all due respect one has to wonder how anyone could have produced such a dogmatic paradigm from such uncertain findings and formulations. Obviously the public must take the experts at their word. But the reality shows that the neo-Darwinian synthesis is a falling out and quarrel of Wright and Fisher, followed by the Pauline ministrations of Dobzhansky who couldn't understand the math. Whatever the case, this has to be one of the best books on evolution going.