Selection component analysis of natural polymorphisms using population samples including mother-offspring combinations

Abstract

The Kaloe population of Zources viviparus was sampled in two successive winters for males, pregnant and non-pregnant females, and the EstlIl genotypes of the fish, including motheroffspring combinations, were scored. The observations were submitted to a selection component analysis which revealed significant evidence of a change in genotypic structure that occurs in the period between the foetal and the adult stage. It is argued that this genotypic distortion, which leads to a gene frequency shift, is most likely due to zygotic selection through either differential survival or differential emigration. The observations indicate that the zygotic gene frequency shift is counteracted by either male sexual or male gametic selection, but there is no statistically significant proof of this contention.

Gene flow and population structure in Armeria maritima

“…No male reproductive selection. As in the original selection component analysis of Christiansen & Frydenberg (1973), male sexual selection and male gametic selection are confounded and their effects on the polymorphism are measured through the combined component male reproductive selection. If plants of the three genotypes produce pollen in equal quantity and heterozygotes segregate H and h in the ratio 1:1, we expect that the frequencies of the two alleles in the pollen are given by a1 + a2/2 = a3 + a2/2, where a1 is the frequency of adult plants in the population.…”

“…The population structure is analysed with a modified version of the selection component analysis described by Christiansen & Frydenberg (1973) for an autosomal locus with two alleles. The effect of natural selection on the variation at the locus is studied by partitioning the selection into the components of gametic, sexual zygotic and fecundity selection.…”

“…By analysing the population structure we can study the impact of gene flow on the genetic differentiation of a group of local populations at a coastal area in Denmark. The population structure was analysed by a modification of the selection component analysis of Christiansen & Frydenberg (1973).…”

Selection component analysis of the PGI polymorphism in Sphaeroma rugicauda

“…Although the method confounds some components and is insensitive to certain sorts of effects it has been applied successfully to biochemical polymorphisms in a variety of organisms; Drosophila (Bungaard and Christiansén, 1972), barley (Hordeum) (Clegg et al, 1978), the fish Zoarces viviparus (Christiansen et aL, 1973), the deer Odocoileus virginianus (Baccus et a!., 1977) and the deer mouse Peromyscus maniculatus (Nadeau and Baccus, 1981). In all of these studies there was evidence of natural selection, with reproductive components more frequently implicated than mortality.…”

“…Sampling and statistical techniques have been developed for selection component analysis (SCA) which allow at least some of the reproductive components of fitness to be estimated (Christiansen and Frydenberg, 1973). These techniques provide an analysis of fecundity, sexual, gametic and zygotic selection using a sample of males, sterile females, fertile females and their offspring.…”