Reinhard Burger

..The expected genetic variance, the expected polymorphic fraction of the genome, as well as other quantities of interest, are only weakly dependent on the selection intensity and the level of recombination...

..e., by nonepistatic loci with dominance. Some of our results are exemplified in this quantitative-genetic context...

..If the favorable allele is (partially) dominant in its deme, more than 20% of all parameter combinations lead to a globally asymptotically stable, fully polymorphic equilibrium...

..Thus, several scenarios are identified under which multilocus polymorphism can be maintained by migration-selection balance when this is impossible in a panmictic population...

..In both cases, every trajectory converges to an equilibrium, thus no cycling or complicated dynamics can occur...

..On the methodological side, we propose quantitative measures for deciding whether a given distribution reflects two (or more) reproductively isolated clusters...

..Even then, the evolutionary outcome depends on the genetics and the initial conditions. The roles of the number of loci, of linkage, and of asymmetric selection are also explored...

..For two loci, the effects of linkage are investigated analytically; for several loci, they are studied numerically...

..Consequences for the maintenance of genetic variation, the detection of disruptive selection, and models of sympatric speciation are discussed...

..We investigate how the genetic variation maintained depends on the ecological parameters and on the underlying genetics...

..For unequal effects, disruptive selection can be observed for weaker competition and in the absence of a stable polymorphism...

..In particular, it is elucidated how this change in genetic variance depends on the reproductive system, the population size, and the selective regime, and what the consequences for population persistence are...

..We discuss possible consequences for the evolution of genetic architecture, in particular, for the emergence of clusters of tightly linked, slightly beneficial mutations and the evolution of recombination and chromosome inversions...

..It also demonstrates that an invasion analysis of mutants of very small effect is insufficient to obtain a full understanding of the evolutionary dynamics under frequency-dependent selection...

..The results are compared with previous analyses of the special case of extremely strong selection, of an approximate model that assumes linkage equilibrium, and of the much simpler quadratic optimum model...