H. Jorjani et al., GENETIC-STUDIES OF ASSORTATIVE MATING - A SIMULATION STUDY .2. ASSORTATIVE MATING IN UNSELECTED POPULATIONS, Acta agriculturae Scandinavica. Section A, Animal science, 47(2), 1997, pp. 74-81
Effects of 25 generations of positive and negative phenotypic assortat
ive mating were compared with that of random mating in unselected (all
individuals reproducing) and randomly chosen (25% of individuals repr
oducing) populations of various size. The trait under assortation was
controlled by either 100 or 2500 loci. Twenty-five generations of posi
tive assortative mating in large unselected populations (effective pop
ulation size equal to 1600) caused an accumulating increase in additiv
e genetic variance (V-A), causing V-A to become 440% of the base popul
ation's V-A. Negative assortative mating had a small asymptotic effect
in the opposite direction, causing V-A to become 72% of the base popu
lation's V-A. Changes in V-A were due almost exclusively to gametic ph
ase (linkage) disequilibrium. Positive and negative assortative mating
were able to slightly increase or decrease the inbreeding coefficient
and the degree of homozygosity. Number of loci, population size and s
tructure had either negligible effects in combination with negative as
sortative mating or worked in the direction of accentuating the effect
s of positive assortative mating. (C) 1997 Scandinavian University Pre
ss.