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Updated: Jun 10, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
Females use multiple mating and genetically loaded sperm competition to target compatible genes
Sarah R Pryke1, Lee A Rollins, Simon C Griffith
1Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
Abstract:
Individuals in socially monogamous species may participate in copulations outside of the pair bond, resulting in extra-pair offspring. Although males benefit from such extra-pair behavior if they produce more offspring, the adaptive function of infidelity to females remains elusive. Here we show that female participation in extra-pair copulations, combined with a genetically loaded process of sperm competition, enables female finches to target genes that are optimally compatible with their own to ensure fertility and optimize offspring viability. Such female behavior, along with the postcopulatory processes demonstrated here, may provide an adaptive function of female infidelity in socially monogamous animals.
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