Absence of species discrimination in Drosophila pseudoobscura and D. persimilis males

Abstract

Despite frequent assumptions in both the theoretical and empirical literature that males are indiscriminate in their courtship, species mating discrimination by males and females are approximately equally frequent in Drosophila. This study looked for evidence of male species discrimination in D. pseudoobscura and D. permilis through both choice and no-choice experiments. The results indicate that males of these species court females indiscriminately. Thus, although male mate choice sexually isolates many other Drosophila species, it does not appear to serve as an isolating mechanism in these sibling species. The implications of the lack of species discrimination by males to speciation and the respective roles of choice and no-choice experiments are discussed.