H. Jorjani et al., GENETIC-STUDIES OF ASSORTATIVE MATING - A SIMULATION STUDY .1. CHARACTERISTICS OF THE CONTROL POPULATIONS, Acta agriculturae Scandinavica. Section A, Animal science, 47(2), 1997, pp. 65-73
Design of control populations to be used in the simulation studies of
assortative mating is discussed. In order to be useful for 25 generati
ons a control population should satisfy the following requirements: (i
) phenotypic correlation of mates, r(p), close to zero; (ii) negligibl
e amount of random drift; and (iii) large number of loci controlling t
he trait under consideration. It was concluded that under the assumpti
ons of the design used in the present study the number of animals to p
roduce a negligible amount of random drift (200 mating pairs) is much
smaller than the number of animals necessary for r(p), to be sufficien
tly close to zero to exclude unconscious assortative mating (400 matin
g pairs). The minimum number of loci required allowing the trait to sh
ow a sufficiently large amount of genetic variation even in long-term
selection studies depends, among other things, on the selection intens
ity and the number of generations involved. In more intensely selected
populations more loci are required. In long-term selection experiment
s with 25 generations and 25% selected, the number of loci required, e
ach with a very small equal effect, was 2500. An unselected control po
pulation fulfilling these requirements behaves similarly to the predic
tions of both the Hardy-Weinberg model and the infinitesimal model. (C
) 1997 Scandinavian University Press.