A macro-equation of natural selection

The deterministic dynamical theory of biological populations, developed widely on the basis of the classical work of Fisher and Volterra, in most cases deals with characteristics which cannot be measured directly, e.g. frequencies of various genotypes within a population, their fitness values, competition coefficients, etc. Thus, a theory dealing with a small number of simple averaged macro-characteristics, easily accessible to a direct measurement, would be of great importance. The present paper contains an attempt to establish an equation contributing to such a would-be macrotheory. It is a relationship begween the average fitness of a population (the Malthusian growth parameter), the selective delay (a new concept, introduction in section 3) and the entropy of the equilibrium structure which the population tends to under the natural selection process. A possible method of checking the proposed relationship experimentally is indicated.