MATING SYSTEM BETWEEN JAPANESE AND FRENCH GEOGRAPHIC STRAINS OF DROSOPHILA MELANOGASTER

Abstract

Teissier has demonstrated biometrically that Japanese and French Drosophila melanogaster form two different geographic races. A study of the mating behavior of these races was undertaken to demonstrate an eventual incipient isolation.
The experiments were performed by direct observation, a technique originally devised by Elens and Wattiaux. Homogamic, selective and panmictic matings were demonstrated in each of the two races as well as between the races. In no case, were homogamic or selective tendencies very pronounced. The morphological differentiation of the geographic races does not result in a change of behavior. This may be explained by the distance between the two races which prevented hybridization; indeed the elimination of hybrids would have reinforced the homogamic tendency.