Simulation of genetic systems : XI. Normalizing selection.

The effects of intense normalizing selection have been studied, using computer simulation, for models of 3, 4, 5, 6, 8, 12 and 24 loci. The effectiveness of such selection in reducing heterozygosity decreases with increase of the number of loci to a limit that is only slightly greater than that consequent from random genetic dispersion, if the loci are freely recombining. Tight linkage markedly reduces the rate of loss of heterozygosity for small numbers of loci, but this effect of tight linkage decreases with increase of the number of loci.