We propose a simple model, based on Monte Carlo simulations, for studying the effects of changes in the environment on the adaptation and extinction of evolving species. We show that the geological data of climatic changes are well described by Levy-stable distributions. This leads, in our...

We propose a model describing the colonization process of empty ecological niches. The members of the population are characterized by a single trait (phenotype). The fitness of an individual is measured as the difference between the value of its trait and the optimal phenotype characterizing the...

A model of a system of populations (metapopulation) is presented in which a population is characterized by a mean phenotype (or equivalently a continuous character) averaged over all individuals belonging to the population. The populations interact by exchanging genetic information (gene flow)...