Population dynamics with and without selection - art. no. 031903

A model describing population dynamics is presented. We study the effect of selection pressure and inbreeding on the time evolution of the population and the chances of survival. We find that the selection is in general benef icial, enabling survival of a population whose size is declining. Inbreedin g reduces the survival chances since it leads to clustering of individuals. We have also found, in agreement with biological data, that there is a thr eshold value of the initial size of the population, as well as of the habit at, below which the population will almost certainly become extinct. We pre sent analytical and computer simulation approaches.