Properties of the Rarefaction Diversity Measurement

increase, unless the pertinent loci are otherwise selected. The second objection stems from the observation that too-weak balancing selection still leaves the population open to loss of variability by drift. But with the present model there is no need to postulate low selection intensity so, at least theoretically, drift becomes less of a problem. Loci, or linkage groups conforming in their demographic characteristics to the Charlesworth-Giesel model, will thus be maintained in a polymorphic state at little or no cost. In addition, any linkage (Franklin and Lewontin 1970) contributes to maintenance of heterozygosity of the rest of the genoiue. The result is perpetuation of population variability and adaptability.