Evolution under stabilizing selection through gene flow

A simple dynamic model is constructed to describe evolutionary changes in populations characterized by a single, quantitative character. The populations interact via gene flow under stabilizing selection. Using standard Monte Carlo simulations we find, in agreement with biological data, that reunion of dispersed populations will lead to one of the three different scenarios, total union of the genetic pools, their partial mixing or complete isolation of the populations. Spatial gradients of the average value of the character were found. The biologically most interesting case, that of partial exchange of the genetic pools, shows some aspects of critical behavior.