Nosil Patrik, Crespi Bernard J
Department of Biosciences, Behavioural Ecology Research Group, Simon Fraser University 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
Proc Biol Sci. 2006 Apr 22;273(1589):991-7. doi: 10.1098/rspb.2005.3359.
Speciation can involve the evolution of 'cryptic' reproductive isolation that occurs after copulation but before hybrid offspring are produced. Because such cryptic barriers to gene exchange involve post-mating sexual interactions, analyses of their evolution have focused on sexual conflict or traditional sexual selection. Here, we show that ecological divergence between populations of herbivorous walking sticks is integral to the evolution of cryptic reproductive isolation. Low female fitness following between-population mating can reduce gene exchange between populations, thus acting as a form of cryptic isolation. Female walking sticks show reduced oviposition rate and lower lifetime fecundity following between-population versus within-population mating, but only for mating between populations using different host-plant species. Our results indicate that even inherently sexual forms of reproductive isolation can evolve as a by-product of ecological divergence and that post-mating sexual interactions do not necessarily evolve independently of the ecological environment.
物种形成可能涉及“隐性”生殖隔离的进化，这种隔离发生在交配之后但在杂交后代产生之前。由于这种对基因交换的隐性障碍涉及交配后的性互动，对其进化的分析主要集中在性冲突或传统的性选择上。在这里，我们表明食草竹节虫种群之间的生态分化是隐性生殖隔离进化的一个组成部分。种群间交配后雌性较低的适应性会减少种群间的基因交换，从而作为一种隐性隔离的形式。与种群内交配相比，种群间交配后雌性竹节虫的产卵率降低，终身繁殖力也较低，但仅适用于使用不同寄主植物物种的种群之间的交配。我们的结果表明，即使是固有的有性生殖隔离形式也可能作为生态分化的副产品而进化，并且交配后的性互动不一定独立于生态环境而进化。
