A population genetics model of linkage disequilibrium in admixed populations

Understanding linkage disequilibrium (LD) created in admixed population and the rate of decay in the disequilibrium over evolution is an important subject in population genetics theory and in disease gene mapping in human populations. The present study represents the theoretical investigation of effects of gene frequencies, levels of LD and admixture proportions of donor populations on the evolutionary dynamics of the LD of the admixed population. We examined the conditions under which the admixed population reached linkage equilibrium or the peak level of the LD. The study reveals the inappropriateness in approximating the dynamics of the LD generated by population admixture by the commonly used formula in literature. An appropriate equation for the dynamics isproposed. The distinct feature of the newly suggested formula is that the value of the nonlinear component of the LD remains constant in the first generation of the population evolution. Comparison between the predicted disequilibrium dynamics sho