1. A computer implemented process for developing a model which predicts the value of a single dependent variable based on the value of at least one independent variable comprising the steps of: (a) providing a dataset containing a plurality of observations each containing a value for said dependent variable and values for said at least one independent variable; (b) creating from said dataset of an initial generation of chromosomes each comprising a predictive model; (c) determining a quantitative fitness measure for each chromosome in said initial generation; and (d) creating a next generation of chromosomes by selecting a number of chromosomes from said initial generation, crossing said selected chromosomes by at least one of a cloning and a crossover technique, and mutating said chromosomes.