Genetic variability of the interpulse interval of courtship song among some European populations of Drosophila melanogaster.

The interpulse interval of the courtship song of Drosophila melanogaster is a character which may play a significant role in mating success and reproductive isolation. Here we examine the variability of interpulse interval among replicated laboratory strains of D. melanogaster. There is no significant variation among populations of different geographical origin. This suggests that interpulse interval is subject to strong selection, as the populations are known to differ for other characters. One population, however, was sufficiently different to allow a genetic analysis. Reciprocal F1s and backcrosses implied that the variance was predominantly additive and autosomal. Possible sources of selection on interpulse interval are discussed.