Further Studies on Genotype Frequency and Mating Success in Drosophila

Abstract

Observations were made in Elens-Wattiaux observation chambers of matings in groups of Drosophila pseudoobscura with different proportions of individuals of CH or with AR chromosomes. Minority males mate more frequently, and majority less frequently, then expected from their relative abundance. When the 2 kinds of males are equally frequent, their matings are also equally frequent. This is true when the numbers of the females and males per chamber are the same, and when the females outnumber the males. Attempts to identify the signals which allow the females to perceive the relative frequency of the males in the chamber have thus far not been successful.