CHANGES OF A CONTINUOUS CHARACTER CAUSED BY GENE FLOW - A MONTE-CARLOSTUDY

We introduce a model of a large, sexual, population in which partners for reproduction are chosen randomly, without any bias. This large pop ulation is composed of two groups of local populations living in diffe rent environments and being in contact. We propose a dynamic equation describing, like the existing one for the allele frequency, the tempor al changes of a continuous character due to gene flow, i.e. the transf er of the allels resulting from migration of individuals between the p opulations, and natural selection. We show that the gene flow can be d escribed by the linear term in the proposed equation and the natural s election by the nonlinear term. Additional killing rule introduces a r andom factor into our model. We discuss the role of both factors (gene flow and selection) on the structure of the population, i.e. spatial distribution of the considered character and the resulting from it exi stence of hybrid zones. We use the standard Monte Carlo simulations. ( C) 1998 Elsevier Science B.V. All rights reserved.