SEXUAL SELECTION AND A SECONDARY SEXUAL CHARACTER IN 2 DROSOPHILA SPECIES

Evidence of sexual selection on male body size and on the number and s ymmetry of sternopleural bristles and of sex comb teeth was sought in natural populations of two Drosophila species. Body size did not diffe r between mating and non-mating males in either species. Mating male D . simulans had significantly fewer sex comb teeth than did males not f ound copulating, and mating male D. pseudoobscura had more sternopleur al bristles. No difference in fluctuating asymmetry of any bilateral t rait was found between mating and non-mating males. These observations suggest that generalizations that large body size and symmetry promot e mating success are unfounded. (C) 1996 The Association for the Study of Animal Behaviour