The Deterministic Behavior of Self-Incompatibility Alleles

For a system of n self-incompatibility alleles, neglecting mutation and random drift, it is shown that the completely symmetric equilibrium is locally stable, and any allelic frequency less than q = 1+a-(see PDF), where a = 2(n - 1)]^-1, will increase. For all n, q > (2n)^-1, but if n > > 1, q ≈ (2n)^-1.