Simulation of the diffusion of the beta-globin variants in the Old World

The distributions of the major hemoglobin variants found in the Old World are simulated assuming that each of the S, C, and E variants had a single origin and that beta-thalassemia occurred as many different mutations. The present distributions of these variants are considered unstable and were best approximated after about 100-150 generations of diffusion and selection. The model is considered to approximate the distributions of these variants better than hypotheses based on multiple mutations.