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Williamson's Theory of Interspecific Competition


IN a recent communication1, Williamson sets out to explore the results of competition between two species of animals living together in the same place. He defines a controlling factor and builds his model on this definition. He says “a car needs more steering on a rough road than on a smooth one” and argues by analogy that a controlling factor is more important in a stochastic than in a deterministic model. Steering is only necessary on any road because the driver wishes to stay alive and reach his destination. Does Williamson imply that controlling factors are necessary because the mathematician wishes to keep his population extant and directed towards his goal? It may be proper for a mathematician to have such a wish but it is scarcely relevant to the study of natural populations since extinction is the usual fate of most populations and probably the inevitable fate of all2.

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  1. 1

    Williamson, M. H., Nature, 180, 422 (1957).

  2. 2

    Andrewartha, H. G., and Birch, L. C., “The Distribution and Abundance of Animals” (University of Chicago Press, 1954).

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