Mutations and changes of the environment in a model of biological evolution

Time evolution of a model of population of diploid organisms is studied using the Monte Carlo technique. Reproduction of the individuals follows the Mendelian rules, including the recombination. We compare the effects of harmful mutations and changes of the environment on the population size, its average adaptation and the average age of the individuals. We show that at short time scale the mutations change the dynamics more deeply. If however the environment was subject to several changes, the effect is much more drastic and may even lead to the extinction of the population.