Principles of polymorphism and epistasis for multilocus systems.

The nature of stable equilibrium configurations is described for general nonepistatic and generalized symmetric viability regimes in multilocus systems under conditions of tight and loose linkage. The influence of epistasis and symmetry can be better understood in terms of these standards. A dichotomy in the nature of stable polymorphisms emerges. More recombination, bisexuality, and multideme interactions facilitate the establishment of central type polymorphisms.