Friday, 5 August 2011

False dating of Fisher on the 'benefit of species'

The earliest backdating of Fisher’s statement about sexual reproduction being due to group selection I have come across is from James F. Crow and Motoo Kimura:
Fisher (1930) goes so far as to suggest that sexuality may be the only character that evolved for species rather than for individual advantage.” (Crow & Kimura 1965, p. 448)
John Maynard Smith opens his response to Crow & Kimura (1965) as follows:
It was argued by Fisher (1930) that sexual reproduction is the only characteristic of living organisms which owes its presence to the fact that it favors the survival of groups rather than of individuals. (Maynard Smith 1968, p. 469)

Both these papers have been republished in a collection of papers called Groups Selection edited by George C. Williams (1971). Williams edited the years out of the texts, so that the backdating did not appear in this collection and Fisher was just mentioned without a year in parentheses following his name. Nevertheless, the false citation of Fisher (1930) rather than (1958) spread. While Williams (1992, p. 47) got the date right, many statements with the untimely date can be found in the literature, for example:
All of the arguments of the previous paper [Felsenstein 1974] were implicitly stated in terms of group selection, in that they described an advantage to a whole population which has recombination. Muller (1932) did not discuss this point, but Fisher (1930) acknowledged explicitly that he was invoking group selection. While he was unwilling to credit group selection with much importance in evolution, he felt forced to make an exception for recombination, which could be interpreted as evolved for the specific rather than the individual advantage.(Felsenstein and Yokoyama 1976, p. 845)
The quote within the quote of Felsenstein and Yokoyama (above) is clearly taken from Fisher (1958) as will be shown below by giving the whole passage that Fisher added to his 1958 edition.
Susan M. Mooney (1995, notes 32, 33) clarified that Fisher’s statement is actually from the section ‘The benefit of the species’ added to the edition of 1958 (to be found on p. 49-50 there).
I only have the Complete Variorum Edition edited by Henry Bennett in 1999 at hand. Here, footnote 2 on page 46 refers to page 279, where the additional section of 1958 is to be found. 

The whole passage reads:
           ‘The benefit of the species’

It will be observed that the principle of Natural Selection, in the form in which it has been stated in this chapter, refers only to the variation among individuals (or co-operative communities), and to the progressive modification of structure or function only in so far as variations in these are of advantage to the individual, in respect to his chances of death or reproduction. It thus affords a rational explanation of structures, reactions and instincts which can be recognized as profitable to their individual possessors. It affords no corresponding explanation for any property of animals or plants which, without being individually advantageous, are supposed to be of service to the species to which they belong.

This distinction was unknown to the early speculations to which the perfection of adaptive contrivances naturally gave rise. For the interpretation that these were due to the particular intention of the Creator would be equally appropriate whether the profit of the individual or of the species were the objective in view. The phrases and arguments of this pre-Darwinian viewpoint have, however, long outlived the philosophy to which they belong. It would be easy to find among modern writers many parallels to the thought expressed in the following quotation:

Of what advantage could it be to any species for the males to struggle for the females and for the females to struggle for the males?’ This sort of question might appropriately be put to an opponent who claimed that the instincts of animals were in each case due to the direct contrivance of the Creator. As a means of progressive change, on the contrary, Natural Selection can only explain these instincts in so far as they are individually beneficial, and leaves entirely open the question as to whether in the aggregate they are a benefit or an injury to the species.

There would, however, be some warrant on historical grounds for saying that the term Natural Selection should include, not only the selective survival of individuals of the same species, but of mutually competing species of the same genus or family. The relative unimportance of this as an evolutionary factor would seem to follow decisively from the small number of closely related species which in fact do come into competition, as compared to the number of individuals in the same species; and from the vastly greater duration of the species compared to the individuals. Any characters ascribed to interspecific selection should of course characterize, not species, but whole genera or families, and it may be doubted if it would be possible to point to any such character, with the possible exception, as suggested in Chapter VI, of sexuality itself, which could be interpreted as evolved for the specific rather than for the individual advantage.” (Fisher 1958 in Bennett 1999, p. 279-280)
Clearly, the last sentence is the one quoted by Felsenstein and Yokoyama (above).
Okay, two things are worth mentioning. Firstly, chapter VI to which Fisher refers is only implicitly group selectionist, and Crow & Kimura (1965) were the first to clearly explicate this -- unless one counts Fisher's additional section from 1958 quoted at length above as the first explication. Chapter VI starts with a definition of species that can also be applied to asexual organisms. 
“The groups most nearly corresponding to species would be those adapted to fill so similar a place in nature that any one individual could replace another, or more explicitly that an evolutionary improvement in any one individual threatens the existence of the descendants of all the others.” (Fisher 1930 in Bennett 1999, p. 121). 
The chapter then proposes an evolutionary race between asexual and sexual ‘species’ in which the one with the higher rate of evolutionary progress wins in the long run (p. 122f).

    Secondly, it strikes me as odd that Fisher invokes the long duration of species in comparison with individuals as a weakness of species selection, while usually the ephemeral nature of groups in comparison with genes has been invoked as a weakness of group selection. 

Ending on a speculative note, this common mistake to believe that Fisher's statement on species selection stemmed from 1930 might even be the reason why Wynne-Edwards (1962, p. 18) claimed: 
 “It is part of our Darwinian heritage to accept the view that natural selection operates largely or entirely at two levels, discriminating on the one hand in favour of individuals that are better adapted and consequently leave more surviving progeny than their fellows; and on the other hand between one species and another where their interests overlap and conflict, and where one proves more efficient in making a living than the other. 

References

  • Crow JF, Kimura M (1965) Evolution in sexual and asexual populations. American Naturalist 99: 439-450
  • Felsenstein J, Yokoyama S (1976) The evolutionary advantage of recombination. II. Individual selection for recombination. Genetics 83: 845-859
  • Fisher (1930/1958) The Genetical Theory of Natural Selection. In: Bennett H (1999) A complete variorum edition. Oxford Univ Press, Oxford
  • Maynard Smith J (1968) Evolution in sexual and asexual Populations. Amer Nat 102: 469-473
  • Mooney SM (1995) H.J. Muller and R.A. Fisher on the evolutionary significance of sex. Journal of the History of Biology 28: 133-149
  • Williams GC (ed) (1971/2008) Group Selection. Aldine Transaction, New Brunswick, NJ
  • Williams GC (1992) Natural Selection. Domains, levels, challenges. Oxford Univ Press, New York


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