Conspecific sperm precedence in Drosophila

摘要: Traits that influence the interactions between males and females can evolve very rapidly through sexual selection1 or sexually antagonistic coevolution2. Rapid change in fertilization systems of independent populations give rise to reproductive incompatibilities populations3,4, may contribute speciation5. Here I provide evidence for cryptic divergence among three sibling species Drosophila leads a form postmating isolation. When female mates with both conspecific heterospecific male, sperm fertilize vast majority eggs, regardless order matings. Heterospecific fewer eggs after these double matings than single Experiments using spermless show seminal fluid male is largely responsible this precedence. Moreover, when two same mate sequentially from different species, highly variable pattern precedence replaces second-male consistently found within species. These results indicate mediate competition, not an automatic consequence mechanics storage.