The direction of linkage disequilibrium.

The previous paper (Langley, Tobari and Kojima 1974) reports that the directional linkage disequilibria, D(omega) = P(AB)P(ab)-P(Ab)P(aB), tend to be negative for data between allozymes and linked to inversions. A and B stand for the two alleles with the greatest frequency in the population. In this paper we show that linkage disequilibrium in this direction is produced at equilibrium when double homozygotes have fitnesses that are a constant fraction of the product of the two component single homozygote fitnesses, a pattern that is frequently observed in experimental data.