Multilocus Behavior in Random Environments. II. Linkage Disequilibrium in an Additive Model.

The effect of a stochastic environment on an additive, two-locus model of a diploid population is examined. The appropriate diffusion equation is derived and its asymptotic properties are approximated by an Orstein-Uhlenbeck process. The first and second order moments of this approximating process are given. The mean linkage disequilibrium will be nonzero if the alleles at the different loci are correlated. The sign of the mean disequilibrium is determined by the sign of the correlation.