DYNAMICS OF 2 POPULATIONS WITH DIFFERENT BIRTH-RATES

We propose a simple model describing the dynamics of a system of two p opulations more numerous natives and less numerous immigrants. The imm igrants' birth rate is higher than that of the natives. Several modifi cations of this model taking into account changes of the birth rates d ue to external factors and/or possibility of contacts between the popu lations, are also introduced. The model is studied within two approach es - by solving a set of differential equations and through a Monte Ca rlo simulations. We show that the question of which population will ev entually dominate depends on such factors as the probability of produc ing offsprings of mixed origin, assimilation of the immigrants, the ra tio of the birth rates, initial numbers of the populations and the ave rage age of an individual. In all, but two extreme cases, both populat ions will survive.