Sexual Signal Evolution Outpaces Ecological Divergence during Electric Fish Species Radiation
Sexual Signal Evolution Outpaces Ecological Divergence during Electric Fish Species Radiation
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DOI：
10.1086/655221
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发表时间：
2010-09-01
影响因子：
2.9
通讯作者：
Hopkins, Carl D.
中科院分区：
文献类型：
--
作者：
Arnegard, Matthew E.;McIntyre, Peter B.;Hopkins, Carl D.
资源竞争和环境异质性产生的自然选择可以驱动适应性辐射。生态机遇促进了这一过程，导致在许多著名的辐射中生态特征迅速分化。在其他情况下，性选择被认为在生态差异之前加剧了交配信号的差异。比较自然和性选择特征之间的差异率可以提供对物种辐射背后的过程的洞察，但到目前为止，这种比较主要是定性的。在这里，我们定量地比较了非洲石斑鱼的四个特征的发散率，这些鱼使用一种对发散几乎没有外部限制的电子通信系统。与形态、大小和营养生态的差异相比，我们证明了副肌无力种群体中信号的快速进化。这种特征进化速度上的差异表明，性选择是这些Mormyrids物种辐射的重要早期驱动因素。我们还发现，在亲缘关系密切的物种之间，生态特征略有差异，这与自然选择在斑潜蝇多样性中的支持作用是一致的。我们的结果突显了当交流的创新在信号空间打开新的机会时，性选择驱动爆炸性信号分歧的潜力，这表明机会可以通过性选择和自然选择催化物种辐射。
Natural selection arising from resource competition and environmental heterogeneity can drive adaptive radiation. Ecological opportunity facilitates this process, resulting in rapid divergence of ecological traits in many celebrated radiations. In other cases, sexual selection is thought to fuel divergence in mating signals ahead of ecological divergence. Comparing divergence rates between naturally and sexually selected traits can offer insights into processes underlying species radiations, but to date such comparisons have been largely qualitative. Here, we quantitatively compare divergence rates for four traits in African mormyrid fishes, which use an electrical communication system with few extrinsic constraints on divergence. We demonstrate rapid signal evolution in the Paramormyrops species flock compared to divergence in morphology, size, and trophic ecology. This disparity in the tempo of trait evolution suggests that sexual selection is an important early driver of species radiation in these mormyrids. We also found slight divergence in ecological traits among closely related species, consistent with a supporting role for natural selection in Paramormyrops diversification. Our results highlight the potential for sexual selection to drive explosive signal divergence when innovations in communication open new opportunities in signal space, suggesting that opportunity can catalyze species radiations through sexual selection, as well as natural selection.