Reichert Michael S, Finck Jonas, Ronacher Bernhard
Institut für Biologie, Abteilung Verhaltensphysiologie, Humboldt-Universität zu Berlin, Ivalidenstrasse 43, 10115, Berlin, Germany.
Current Address: School of Biological, Earth and Environmental Sciences, University College Cork, G15 Cooperage Building, Cork, Ireland.
Evolution. 2017 Apr;71(4):1009-1024. doi: 10.1111/evo.13202. Epub 2017 Mar 1.
A major challenge in evolutionary biology is explaining the origins of complex phenotypic diversity. In animal communication, complex signals may evolve from simpler signals because novel signal elements exploit preexisting biases in receivers' sensory systems. Investigating the shape of female preference functions for novel signal characteristics is a powerful, but underutilized, method to describe the adaptive landscape potentially guiding complex signal evolution. We measured female preference functions for characteristics of acoustic appendages added to male calling songs in the grasshopper Chorthippus biguttulus, which naturally produces only simple songs. We discovered both hidden preferences for and biases against novel complex songs, and identified rules governing song attractiveness based on multiple characteristics of both the base song and appendage. The appendage's temporal position and duration were especially important: long appendages preceding the song often made songs less attractive, while following appendages were neutral or weakly attractive. Appendages had stronger effects on songs of shorter duration, but did not restore the attractiveness of very unattractive songs. We conclude that sensory biases favor, within predictable limits, the evolution of complex songs in grasshoppers. The function-valued approach is an important tool in determining the generality of these limits in other taxa and signaling modalities.
进化生物学中的一个主要挑战是解释复杂表型多样性的起源。在动物通讯中，复杂信号可能从简单信号进化而来，因为新的信号元素利用了接收者感官系统中预先存在的偏好。研究雌性对新信号特征的偏好函数的形状是一种强大但未充分利用的方法，可用于描述可能指导复杂信号进化的适应性景观。我们测量了雌性对添加到雄性大垫尖翅蝗鸣叫歌曲中的声学附属物特征的偏好函数，这种蝗虫自然只产生简单的歌曲。我们发现了对新复杂歌曲的隐藏偏好和偏见，并根据基础歌曲和附属物的多种特征确定了控制歌曲吸引力的规则。附属物的时间位置和持续时间尤为重要：在歌曲之前出现的长附属物通常会使歌曲吸引力降低，而跟随在歌曲之后的附属物则是中性的或吸引力较弱。附属物对持续时间较短的歌曲影响更大，但并不能恢复非常不吸引人的歌曲的吸引力。我们得出结论，感官偏好会在可预测的范围内促进蝗虫复杂歌曲的进化。函数值方法是确定这些范围在其他分类群和信号传导方式中的普遍性的重要工具。
