Untitled [On Evolution in Organic and Inorganic Systems]

Abstract

The order of ideas which has given birth to the modern theory of organic evolution is by its nature essentially quantitative. We know that Darwin, and Wallace as well, were drawn to the enunciation of the principle of survival of the fittest through reflection on the problem first posed by Malthus: how is the number of living organisms maintained within the limits we in fact observe? By a rather singular coincidence this aspect of the problem of evolution, which, it would seem, would have been the first to attract the attention of biologists predisposed to mathematical analysis, has only quite recently received their serious attention. A certain school, it is true, profiting by the work in genetics of Gregor Mendel among others, has been occupied for some years with biometrical anal-ysis applied to questions of survival and reproduction in their relation to the problem of organic evolution. But, in their research, the disciples of this school have limited themselves almost entirely to the discussion of the characteristics of a single species and the consequences of these characteristics as they affect its survival. The interaction of diverse species among themselves and with their habitat has received at most passing and incidental consideration by these authors. Ecologists, by contrast, have been content almost entirely with empirical studies on this subject.