FOUR SIMULTANEOUSLY STABLE POLYMORPHIC EQUILIBRIA IN TWO-LOCUS TWO-ALLELE MODELS

1 Department of Mathematics and Division of Environmental Studies, University of California, Davis, California 95616

The existence of four simultaneously stable equilibria with both loci polymorphic is shown for the Lewontin-Kojima version of the two-locus two-allele symmetric viability model, using bifurcation theory. This exceeds the previously claimed bound of two stable polymorphisms. Biological implications of the result are discussed.

Submitted on July 9, 1984
Accepted on September 17, 1984