Department of Biology, University of Central Florida, 4000 Central Florida Boulevard, Orlando, 32816-2368 Florida, USA.
Evolution. 2011 Jun;65(6):1650-66. doi: 10.1111/j.1558-5646.2011.01245.x. Epub 2011 Mar 4.
The reproductive signals of two or more taxa may diverge in areas of sympatry, due to selection against costly reproductive interference. This divergence, termed reproductive character displacement (RCD), is expected in species-rich assemblages, where interspecific signal partitioning among closely related species is common. However, RCD is usually documented from simple two-taxon cases, via geographical tests for greater divergence of reproductive traits in sympatry than in allopatry. We propose a novel approach to recognizing and understanding RCD in multi-species communities--one that traces the displacement of signals within multivariate signal space during the ontogeny of individual animals. We argue that a case for RCD can be made if the amount of signal displacement between a pair of species after maturation is negatively correlated to distance in signal space before maturation. Our application of this approach, using a dataset of communication signals from a sympatric Amazonian assemblage of the electric fish genus Gymnotus, provides strong evidence for RCD among multiple species. We argue that RCD arose from the costs of heterospecific mismating, but interacted with sexual selection--favoring the evolution of conspicuous male signals that not only serve for mate-choice, but which simultaneously facilitate species recognition.
两个或多个分类单元的繁殖信号可能在同域地区出现分歧，这是由于选择会对代价高昂的繁殖干扰产生排斥。这种分歧被称为繁殖特征替代（RCD），在物种丰富的组合中很常见，因为在亲缘关系密切的物种之间，信号的种间划分很常见。然而，RCD 通常是通过对生殖特征在同域比在异域中更大分歧的地理测试，从简单的二分类案例中记录下来的。我们提出了一种识别和理解多物种群落中 RCD 的新方法——一种在个体动物的个体发育过程中追踪多元信号空间中信号替代的方法。我们认为，如果一对物种在成熟后的信号位移量与成熟前信号空间中的距离呈负相关，则可以认为存在 RCD。我们应用这种方法对来自亚马逊同域电鱼属 Gymnotus 的一个集合的通讯信号数据集进行了研究，为多种物种之间的 RCD 提供了有力证据。我们认为 RCD 是由异配的代价引起的，但与性选择相互作用——有利于进化出显眼的雄性信号，这些信号不仅用于配偶选择，而且同时有助于物种识别。
