I N his careful essay discussing Ruse’s The Philosophy of Biology Ronald Munson refers to the debate over the possibility of group selection: the possibility that some characteristics of organisms develop not because they are adaptive for the individual but because they are adaptive for the group, thus implying that a process of selection between groups takes place.’ One very important issue that hangs on this debate, I believe, is the legitimacy of sociological functionalism in its classical form, which urges that the institutions of a society should be understood as being there in order to perform functions which need performing if the society is to continue to flourish. This theory is generally dismissed in recent work, on the grounds that there is no satisfactory explanation of the mechanism whereby such a functional organization could have been adopted.’ My present point is that group-selection would of course provide such a mechanism. Just as we can understand how individual selection has built into the human being an unconscious recognition of his individual needs, and the motivation to pursue their satisfaction, so group selection could have built into the individual a recognition of society’s needs, together with the motivation to behave in such a way as to satisfy them. Thus, individual selection has endowed us with the motivation to sleep from time to time (even though we might not recognize that we need to sleep), and group selection may be responsible for our motivation to engage in religious practices or their functional equivalent, if it is true that these serve to integrate the groups that practices them. For someone who finds a functional approach to society attractive, therefore, the possibility of group selection is of great interest; but having awakened it, Munson damps it thoroughly down by claiming that it is recognized as a possibility by a small minority of biologists only. But I wonder if this is not partially misleading? There seems in this case to be a difference between what biologists are prepared to say when ’
of Science 5 (Ig74), 80. 2 e.g. M. Levy, contribution
L. Sills (ed.).
The Philosophy of Biolqy, in Studies in History and Philosophy
to the article on ‘Functional Analysis’ in The Encyclopaedia of the See also A. Ryan, The Philosophy of the Social Sciences (London,
Stud. Hist. Phil. Sci., 5 (Ig75),
no. 4. Printed
Studies in History and Philosophy of Science
addressing the particular theoretical issue of whether group selection occurs, and what they are prepared to commit themselves to in discussing particular adaptations, when the general the forefront of their minds.
issue may not be in
Maynard-Smith has drawn attention recently3 to the example which makes this point best: the evolution of sexual reproduction. It is perfectly orthodox to explain the value of this phenomenon in terms of its adaptive value for the group in which it occurs, a typical account being that it increases enormously the degree to which a given gene combines with others of the gene-pool, with the result that a given population is more plastic and evolution proceeds at a faster rate.4 This is an advantage to the group however, and not to the individual. And indeed it is difficult to see how the phenomenon of sex could be of advantage to the individual, with all the complexities and dangers in which it involves the reproductive process. It is true that arguments have been mounted against these points and that the explicit thesis that group selection does not occur to any significant extent has found its defenders. C. G. Williams is perhaps the most determined of these, particularly in his lucid and powerful discussion Adaptation and Natural Selection.5 But the very fact that Williams felt it necessary to engage in these arguments-and his tone is distinctly polemical-indicates, I think, that the acceptance of group selection, tacit, if not explicit, is widespread among biologists, and is not the extreme minority view that Munson suggests. The mere fact that a view is widespread is not of course a very strong argument for its truth; but the real encouragement for those who have an interest in group selection’s being recognized is that many biologists, pace Williams, seem to have difficulty in explaining the origin of certain characteristics without tacitly invoking it. University College, Cardi$ s J. Maynard Smith, ‘The Origin and Maintenance of Sex’, Croup Selection, G. C. Williams (ed.) (Chicago, IgTI), x63-75. 4 See e.g. E. Mayr, Animal Species and Evolution (Cambridge, Mass., 1g73), 179; J. Huxley, Evolution, The Modern Synthesis (2nd edn.) (London, Ig63), 83,84; and R. A. Fisher, The Genetical Theory of Natural Selection (Oxford, x930), 121-3. ’ G. C. Williams, Adafitation and .NataturalSelection (Princeton, 1966). Other defenders are referred to in R. K. Selander, ‘Sexual Selection and Dimophism in Birds’, reprinted in B. Campbell, Sexual Selection and the Descent of Man (London, Ig72), rg2.