Levels of multiallelic overdominance fitness, heterozygote excess and heterozygote deficiency.

Concepts and results on selection balance in multiallelic systems are described. These include a multidimensional concept of heterozygote excess and heterozygote deficiency, a hierarchy of means of assessment of heterozygote advantage, comparisons and contrasts of allelic versus gametic polymorphic states, and conditions defining stable equilibria of complementary gametic sets. The concepts are illustrated in the context of viability selection and behavioral models of kin selection and for two major categories of multilocus selection regimes.