J. B. S. Haldane

Abstract

These are the closing words of J. B. S. Haldane’s The Causes of Evolution, published in 1932. Today, when one cannot discuss how some animal goes about finding its daily bread without basing the discussion on a mathematical model, it may seem strange that there was a time when ecology and evolution theory were free of mathematics. The investigations Haldane refers to are those carried out by R. A. Fisher, Sewall Wright, and himself into the genetic basis of evolutionary change. In fact, there had been an earlier phase in the mathematical treatment of evolution, by the biometrical school led by Karl Pearson; but this earlier approach was different, not merely in detail, but in its whole philosophy. For Pearson, the business of science was to provide a mathematical description of the world, but not to explain the behaviour of things in terms of some underlying mechanism. He went so far in this view as to deny the reality of atoms, because he thought it illegitimate to postulate the existence of unseen entities. It is not surprising that he also rejected genes. As a result, the work of the biometricians, although important in developing statistical techniques of value in the analysis of data, did little to illuminate the mechanisms of evolution. In contrast, Haldane and his contemporaries attempted to deduce, from the known principles of Mendelian genetics, how populations might be expected to evolve, and to compare their deductions with observation.

The permeation of biology by mathematics is only beginning, but unless the history of science is an inadequate guide, it will continue, and the investigations here summarised represent the beginning of a new branch of applied mathematics.

This is an expanded version of the article: Maynard Smith, J., “J. B. S. Haldane”, Oxford Surveys in Evolutionary Biology, 1986, by permission of Oxford University Press.