NO EVIDENCE THAT POLYANDRY BENEFITS FEMALES IN DROSOPHILA MELANOGASTER
Version of Record online: 9 MAY 2007
Volume 58, Issue 6, pages 1242–1250, June 2004
How to Cite
Brown, W. D., Bjork, A., Schneider, K. and Pitnick, S. (2004), NO EVIDENCE THAT POLYANDRY BENEFITS FEMALES IN DROSOPHILA MELANOGASTER. Evolution, 58: 1242–1250. doi: 10.1111/j.0014-3820.2004.tb01703.x
- Issue online: 9 MAY 2007
- Version of Record online: 9 MAY 2007
- Received June 27, 2003. Accepted February 11, 2004.
- Multiple mating;
- offspring viability;
- reproductive success;
- sexual selection;
- sperm competition
Abstract Understanding the evolution of polyandry (mating with multiple males) is a major issue in the study of animal breeding systems. We examined the adaptive significance of polyandry in Drosophila melanogaster, a species with well-documented costs of mating in which males generally cannot force copulations. We found no direct fitness advantages of polyandry. Females that mated with multiple males had no greater mean fitness and no different variance in fitness than females that mated repeatedly with the same male. Subcomponents of reproductive success, including fecundity, egg hatch rate, larval viability, and larval development time, also did not differ between polyandrous and monogamous females. Polyandry had no affect on progeny sex ratios, suggesting that polyandry does not function against costly sex-ratio distorters. We also found no evidence that polyandry functions to favor the paternity of males successful in precopulatory sexual selection. Experimentally controlled opportunities for precopulatory sexual selection had no effect on postcopulatory sperm precedence. Although these results were generally negative, they are supported with substantial statistical power and they help narrow the list of evolutionary explanations for polyandry in an important model species.