The Response to Selection Equation for SkewFitness Distributions 1

| The equation for the response to selection is a powerful analysis and modeling tool for genetic algorithms. In this paper we extend the classical analysis which is restricted to a normal distribution to skew tness distributions. We show that for a small number of variables the Gamma distribution ts the distribution of the tness values better than a normal distribution. We compute the selection intensities for the Gamma distribution. It is shown that with these values the prediction for the mean tness of the population is very accurate. Finally we show that multi-modal functions may lead to tness distributions having several modal values.