On evolution / John Maynard Smith.

  • Maynard Smith, John, 1920-2004.
Date:
1972
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: On evolution / John Maynard Smith. Source: Wellcome Collection.

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    they are willing to accept some point merely because it is unique. Clearly, this concept can be applied only when the resource which is being competed for is divisible. An obvious application is to territorial disputes between animals; it seemed worth enquiring whether there is an animal equivalent of the 49th parallel. In fact, it appears that there is. Animals will often settle on some feature which has no relevance to survival as a territorial boundary; for example, mice will adopt a chalk mark on the floor of their cage as a boundary. I do not want to make too much of this aspect of ritualized displays; mice can settle on a territorial boundary without the help of a chalk mark. Two points are important for my argu¬ ment. First, ritualized conflicts can be settled, because not to settle wastes time and energy and may risk injury. Second, game theory predicts a 'canalization' or 'typical intensity' of ritualized acts used as threats; there is evidence for such canalization in some cases, but it is not universal, and the reasons for the departure from the principle of canalization are not clear. Conclusion In this essay I have drawn analogies between human and animal conflicts, and applied to the evolution of animal be¬ haviour concepts of game theory which were developed to analyze human conflicts. In general, I am somewhat distrustful of analogies of this kind, so in conclusion I want to say some¬ thing in defence of my use of them. When an analogy is drawn between a human and an animal action—for example, between a boxing match and a fight between two stags—one of two very different points may be being made. First, it may be being suggested that the physiological mechanisms under¬ lying the two actions may be similar; for example, that the same hormones may be important in the two cases. This is the type of conclusion from animal-human analogies that I dis¬ trust. There may or may not be physiological similarities between human and animal aggression, but nothing I have said in this essay is intended as evidence for such similarity. The second reason for using an analogy is the belief that there is a logical similarity between two processes. Most uses of analogy in science are of this kind. 2° For example, engineers used to draw an analogy between the stresses in a beam and the shape of a soap bubble, because the equations describing 26