Preface. Divergence in mate choice systems: does evolution play by rules? W.J. Etges. Recombination and the divergence of hybridizing species; D. Ortiz-Barrientos, J. Reiland, J. Hey, M.A.F. Noor. The evolution of hybrid infertility: perpetual coevolution between gender-specific and sexually antagonistic genes; W.R. Rice, A.K. Chippindale. Modelling the evolution of female choice strategies under inbreeding conditions; K. Reinhold. Single gene mutations in Drosophila: what can they tell us about the evolution of sexual behaviour? C.P. Kyriacou. Sexual signaling and speciation, a microevolutionary perspective; C.R.B. Boake. Reproductive isolation in natural populations of Drosophila melanogaster from Brazzaville (Congo); W. Haerty, J.M. Jallon, J. Rouault, C. Bazin, P. Capy. Genetics of sexual isolation based on courtship song between two sympatric species: Drosophila ananassae and D. pallidosa; H. Yamada, M. Matsuda, Y. Oguma. Evolutionary experiments on mate recognition in the Drosophila serrata species complex; M.W. Blows, M. Higgie. Herbivorous insects: model systems for the comparative study of speciation ecology; D.J. Funk, K.E. Filchak, J.L. Feder. The inheritance of mating songs in two cryptic, sibling lacewing species (Neuroptera: Chrysopidae: Chrysoperla); C.S. Henry, M.L. Martinez Wells, K.E. Holsinger. Divergence and reproductive isolation in the early stages of speciation; T. Tregenza. Genetic and behavioral components of the cryptic species boundary between Laupala cerasina and L. kohalensis (Orthoptera: Gryllidae); T.C. Mendelson, K.L. Shaw. Domesticated birds as a model for the genetics of speciation by sexual selection; T.D. Price. Patterns of inheritance of mating signals in interspecific hybrids between sailfin and shortfin mollies (Poediluidae: Poecilia: Mollienesia); M.B. Ptacek. Variation in female mate choice within guppy populations: population divergence, multiple ornaments and the maintenance of polymorphism; R. Brooks. Sexual isolation and speciation in bacteria; F.M. Cohan. Mutation and premating isolation; R.C. Woodruff, J.N. Thompson Jr. Female choice in Drosophila: evidence from Hawaii and implications for evolutionary biology; H.L. Carson. Acknowledgements for refereeing. Subject and species index.