Indian Institute of Science Education and Research Mohali, Knowledge City, Sector 81, SAS Nagar, PO Manauli, Mohali, Punjab, 140306, India.
Sci Rep. 2017 Jun 13;7(1):3330. doi: 10.1038/s41598-017-03182-1.
Promiscuity can drive the evolution of sexual conflict before and after mating occurs. Post mating, the male ejaculate can selfishly manipulate female physiology, leading to a chemical arms race between the sexes. Theory suggests that drift and sexually antagonistic coevolution can cause allopatric populations to evolve different chemical interactions between the sexes, thereby leading to postmating reproductive barriers and speciation. There is, however, little empirical evidence supporting this form of speciation. We tested this theory by creating an experimental evolutionary model of Drosophila melanogaster populations undergoing different levels of interlocus sexual conflict. We found that allopatric populations under elevated sexual conflict show assortative mating, indicating premating reproductive isolation. Further, these allopatric populations also show reduced copulation duration and sperm defense ability when mating happens between individuals across populations compared to that within the same population, indicating postmating prezygotic isolation. Sexual conflict can cause reproductive isolation in allopatric populations through the coevolution of chemical (postmating prezygotic) as well as behavioural (premating) interactions between the sexes. Thus, to our knowledge, we provide the first comprehensive evidence of postmating (as well as premating) reproductive isolation due to sexual conflict.
滥交可以在交配前后推动性冲突的进化。交配后，雄性精液可以自私地操纵雌性生理，导致两性之间的化学军备竞赛。理论表明，漂变和性拮抗协同进化可能导致异地种群之间的性别之间产生不同的化学相互作用，从而导致交配后生殖隔离和物种形成。然而，很少有实证证据支持这种形式的物种形成。我们通过创建一个经历不同程度基因间性冲突的黑腹果蝇种群的实验进化模型来检验这一理论。我们发现，处于高性冲突的异地种群表现出选择性交配，表明存在交配前生殖隔离。此外，当个体在种群之间交配时，与在同一种群内交配相比，这些异地种群的交配持续时间和精子防御能力也降低，表明存在交配后合子前隔离。性冲突可以通过性别之间的化学（交配后合子前）和行为（交配前）相互作用的共同进化，导致异地种群的生殖隔离。因此，据我们所知，我们首次提供了由于性冲突导致的交配后（以及交配前）生殖隔离的综合证据。
