if wu $ < or if 0 < < p and

For a proof of Lemma 1, see [9, 16, 19). The solution in case (d) is known as the Hardu-Weinberg equilibrium. With no selection the allele frequency remains constant over time. Results similar to Lemma 1 apply to the general model (1), however, determining the limit becomes a matter of cataloging the relationships among the fitness values, e.g., when w11 > Wij, ij :1: 11, then limt-+ooPt = e1.