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SEXUAL SELECTION AGAINST HYBRIDS BETWEEN SYMPATRIC STICKLEBACK SPECIES: EVIDENCE FROM A FIELD EXPERIMENT
Author(s) -
Vamosi Steven M.,
Schluter Dolph
Publication year - 1999
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1999.tb05381.x
Subject(s) - biology , limnetic zone , sexual selection , reproductive isolation , sympatric speciation , gasterosteus , stickleback , ecological speciation , mating , hybrid , sympatry , ecological selection , selection (genetic algorithm) , mating preferences , mate choice , zoology , assortative mating , disruptive selection , ecology , evolutionary biology , natural selection , population , genetic variation , gene flow , genetics , fishery , demography , littoral zone , artificial intelligence , sociology , computer science , fish <actinopterygii> , botany , gene
Sexual selection against viable, fertile hybrids may contribute to reproductive isolation between recently diverged species. If so, then sexual selection may be implicated in the speciation process. Laboratory measures of the mating success of hybrids may underestimate the amount of sexual selection against them if selection pressures are habitat specific. Male F 1 hybrids between sympatric benthic and limnetic sticklebacks ( Gasterosteus aculeatus complex) do not suffer a mating disadvantage when tested in the laboratory. However, in the wild males choose different microhabitats and parental females tend to be found in the same habitats as conspecific males. This sets up the opportunity for sexual selection against male hybrids because they must compete with parental males for access to parental females. To test for sexual selection against adult F 1 hybrid males, we examined their mating success in enclosures in their preferred habitat (open, unvegetated substrate) where limnetic males and females also predominate. We found significantly reduced mating success in F 1 hybrid males compared with limnetic males. Thus, sexual selection, like other mechanisms of postzygotic isolation between young sister species, may be stronger in a wild setting than in the laboratory because of habitat‐specific selection pressures. Our results are consistent with, but do not confirm, a role for sexual selection in stickleback speciation.