Free The Extended Phenotype: The Long Reach of the Gene (Popular Science) by Richard Dawkins

of this chapter I expressed doubts that anyone was truly an adaptationist in the extreme sense, but I have recently found the following quotation from, ironically enough, Lewontin himself: ‘That is the one point which I think all evolutionists are agreed upon, that it is virtually impossible to do a better job than an organism is doing in its own environment’ (Lewontin 1967). Lewontin has since, it seems, travelled his road to Damascus, so it would be unfair to use him as my adaptationist spokesman. Indeed together with Gould he has, in recent years, been one of the most articulate and forceful critics of adaptationism. As my representative adaptationist I take A. J. Cain, who has remained (Cain 1979) consistently true to the views expressed in his trenchant and elegant paper on ‘The perfection of animals’.
    Writing as a taxonomist, Cain (1964) is concerned to attack the traditional dichotomy between ‘functional’ characters, which by implication are not reliable taxonomic indicators, and ‘ancestral’ characters which are. Cain argues forcefully that ancient ‘groundplan’ characters, like the pentadactyl limb of tetrapods and the aquatic phase of amphibians, are there because they are functionally useful, rather than because they are inescapable historical legacies as is often implied. If one of two groups ‘is in any way more primitive than the other, then its primitiveness must in itself be anadaptation to some less specialized mode of life which it can pursue successfully; it cannot be merely a sign of inefficiency’ (p. 57). Cain makes a similar point about so-called trivial characters, criticizing Darwin for being too ready, under the at first sight surprising influence of Richard Owen, to concede functionlessness: ‘No one will suppose that the stripes on the whelp of a lion, or the spots on the young blackbird, are of any use to these animals …’ Darwin’s remark must sound foolhardy today even to the most extreme critic of adaptationism. Indeed, history seems to be on the side of the adaptationists, in the sense that in particular instances they have confounded the scoffers again and again. Cain’s own celebrated work, with Sheppard and their school, on the selection pressures maintaining the banding polymorphism in the snail
Cepaea nemoralis
may have been partly provoked by the fact that ‘it had been confidently asserted that it could not matter to a snail whether it had one band on its shell or two’ (Cain, p. 48). ‘But perhaps the most remarkable functional interpretation of a “trivial” character is given by Manton’s work on the diplopod
Polyxenus
, in which she has shown that a character formerly described as an “ornament” (and what could sound more useless?) is almost literally the pivot of the animal’s life’ (Cain, p. 51).
    Adaptationism as a working hypothesis, almost as a faith, has undoubtedly been the inspiration for some outstanding discoveries. von Frisch (1967), in defiance of the prestigious orthodoxy of von Hess, conclusively demonstrated colour vision in fish and in honeybees by controlled experiments. He was driven to undertake those experiments by his refusal to believe that, for example, the colours of flowers were there for no reason, or simply to delight men’s eyes. This is, of course, not evidence for the validity of adaptationist faith. Each question must be tackled afresh, on its merits.
    Wenner (1971) performed a valuable service in questioning von Frisch’s dance language hypothesis, since he provoked J. L. Gould’s (1976) brilliant confirmation of von Frisch’s theory. If Wenner had been more of an adaptationist Gould’s research might never have been done, but Wenner would also not have allowed himself to be so blithely wrong. Any adaptationist, while perhaps conceding that Wenner had usefully exposed lacunae in von Frisch’s original experimental design, would instantly have jumped, with Lindauer (1971), on the fundamental question of why