Wednesday, September 30, 2015

Paging Dr. Pangloss

20 years ago...
Neo-Darwinism has failed as an evolutionary theory that can explain the origin of species, understood as organisms of distinctive form and behaviour. In other words, it is not an adequate theory of evolution. What it does provide is a partial theory of adaptation, or microevolution (small-scale adaptive changes in organisms). It is partial in two senses. First, Neo-Darwinism assumes random genetic variation followed by selection, whereas there is now evidence for a role of directed mutation in adaptive response. That is, genes can evidently respond to environmental circumstances by non-random, adaptive mutation. And second, many of the adaptive "explanations" advanced for biological characteristics simply cannot be taken as serious science. In 1979, Steven Jay Gould and Richard Lewontin published a classic paper that ridiculed much of the adaptationist literature as constituting a "panglossian paradigm", Just So Stories of such dubious scientific value that they discredit the subject. For a few years after that, adaptationists watched their p's and q's more closely. However, the salutary influence of that paper has unfortunately diminished to the point where Just So Stories are again proliferating wildly. A recent example is why the hour-glass shape in women is an adaptive trait, determined by genes. Men select women with large hips and breasts because these are indicators of reproductive potential, or at least men think they are. Women who satisfy these criteria but do not have a small waist are simply fat, which, we are told, is not a good indicator of reproductive potential. Hence the selection of the hour-glass shape. You might think I overheard this in a pub, but it is in fact advanced as a serious proposition by Matt Ridley in The Red Queen following the original proposal by Low, Alexander, and Noonan in Ethology and Sociobiology. If this is science then Rudyard Kipling was a great scientist.  -- Brian Goodwin, biologist, "Neo-Darwinism Has Failed as an Evolutionary Theory"

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