Assortative mating for a metrical characteristic in Drosophila

Variations in mating propensities in strains of Drosophila melanogaster with different scutellar chaeta numbers

“…Results of Thoday (1964) indicate that positive assortative mating occurs within the high and low lines. In agreement are results of Parsons (1965), who showed positive assortative mating for sternopleural chaeta number in an outbred Canton-S strain. In this paper we will present results on mating behaviour for three lines, which have been subjected to directional selection for 73 generations for high scutellar chaeta number by selecting in each generation 10 flies of each sex with the highest chaeta number, out of 100 (detailed results will be presented in a subsequent publication by MacBean, McKenzie and Parsons). In brief, the three lines to be discussed are characterised as follows:…”

Progress in the Use of Chromosomal Translocations for the Control of Insect Pests

“…In a field population into which translocation homozygotes have been released there would be a strong selective pressure for the evolution of assortative mating to prevent the generation of semi-sterile heterozygotes. The evolution of assortative mating for mutant traits has already been observed in laboratory populations of Drosophila (Thoday & Gibson, 1962; Parsons, 1965) but no such development was observed in laboratory populations containing translocation homozygotes and wild-type flies (Robinson, 1971). Further, as the segregation and hence the fertility of the translocation heterozygote is under genetic control and can therefore be modified by selection, there is a possibility that natural selection would tend to increase the fertility of the translocation heterozygote once it had been released into a natural population.…”

THE RELATIONSHIP BETWEEN MATING SPEED AND WING LENGTH INDROSOPHILA SUBOBSCURA

“…This could be due to assortative mating of the males with longer wings and the females with the same trait. Parsons (1965) assumes assortative mating for size as a possible explanation of the assortative mating found for steroopleural bristles in his experiments. However, in our data no correlation in wing length is found within pairs of mated flies.…”