SELECTION FOR LINKAGE MODIFICATION II. A RECOMBINATION BALANCE FOR NEUTRAL MODIFIERS

Marcus W. Feldman ¹ and Beverley Balkau ²

¹ Department of Biological Sciences, Stanford University, Stanford, California 94305
² Department of Mathematics, La Trobe University, Bundoora, Victoria 3083, Australia

A stable polymorphic equilibrium may be established at a selectively-neutral gene locus which controls the extent of recombination between two other selected loci. The condition for the existence of the stable polymorphism is analogous to heterozygous advantage. The heterozygote at the modifying locus should produce a recombination fraction allowing the greatest linkage disequilibrium. In the models treated this has the effect of producing the highest mean fitness. The relationship of these findings to general problems of coadaptation is discussed.