A model of population dynamics—further investigations

Abstract

We present supplementary investigations referring to the model of an evolving population described in Physica A 252 (1998) 325. The population is composed of individuals characterised by their genetic strings, phenotypes and ages. We discuss the influence of probabilities of survival of the individuals on the dynamics and phenotypic variability of the population. We show that constant survival probabilities of individuals are propitious for preserving phenotypic variability of the population. For constant survival probabilities oscillations of ‘the average fitness’ of the population and normal distributions of the phenotypes are observed. When the probabilities of survival are directly proportional to the individuals’ adaptations the population can reach the maximum possible average adaptation, but the phenotypic variability of the population is completely lost and oscillations of ‘the average fitness’ of the population do not occur. We also investigate the behaviour of the population caused by the probabilities of survival that partly depend on the individuals’ adaptations. The role of the length of the individuals’ genetic strings is considered here.