Neo-Darwinism is, very roughly, the claim that natural selection is by far the most important explanation of biological form, the particular characteristics of particular kinds of organism. It usually includes a commitment to gradualism (the idea that evolution occurs in small steps), and often involves attributing central importance to genes as the units that natural selection selects, or at any rate as the objective measure of evolutionary change. Versions have been prominently defended in recent years by such authors as Richard Dawkins, Daniel Dennett and Jerry Coyne.
Neo-Darwinism is, however, a perspective under ever-growing pressure, not (or not only) from the antiscientific assaults of the religious, but from the advancement of science. The decline of this intellectual monolith is generally to be welcomed, not least because it may be expected to bring down with it some of its less appetising academic fellow travellers, most notably Evolutionary Psychology. At the same time those contributing to the demise of neo-Darwinism must be aware of the risk, especially in the United States, that they will provide succour for fundamentalist Creationists and aficionados of so-called Intelligent Design.
Fodor and Piatelli-Palmarini’s (henceforth FPP) book is intended as a contribution to the critical task just mentioned, and they are well aware of the potential hazards. Sadly, however, the book is an almost tragic failure: it is unlikely to be taken seriously as a contribution to the dismantling of neo-Darwinism and it has been, and will continue to be, picked up by the fundamentalist enemies of science.
The first half of the book does a decent job of summarising the recent scientific insights responsible for the growing difficulties facing neo-Darwinism. Neo-Darwinism, by virtue of its emphasis on natural selection, sees evolution as driven from outside, by the environment. Central among the difficulties that FPP emphasise are crucial respects in which evolution is constrained, or even driven, by internal features of the organism. This realisation has been promoted by evolutionary developmental biology (“evo-devo”), which has also highlighted the unacceptable black-boxing of development in mainstream evolutionary theory, a concomitant of the exclusive focus on external determinants of change. Also crucial has been a gradual move away from excessively atomistic views of organisms and an appreciation of the necessity of treating them as integrated wholes, illustrated by the impossibility of analysing the genome into a unique set of discrete elements, “genes”. And equally important has been the disclosure of the complexity of the relations between genomes and phenotypes.
While much material is presented that does indeed reveal the dire straits in which neo-Darwinism finds itself, the overall argument is generally elusive. I speculate that this is because there are two quite different conclusions in the offing.