Data from: Macroevolution of perfume signalling in orchid bees

Theory predicts that both stabilising selection and diversifying selection jointly contribute to the evolution of sexual signalling traits by (1) maintaining the integrity of communication signals within species and (2) promoting the diversification of traits among lineages. However, for many important signalling traits, little is known about whether these dynamics translate into predictable macroevolutionary signatures. Here, we test for macroevolutionary patterns consistent with sexual signalling theory in the perfume signals of neotropical orchid bees, a group well studied for their chemical sexual communication. Our results revealed both high species-specificity and elevated rates of evolution in perfume signals compared to nonsignalling traits. Perfume complexity was correlated with the number of congeners in a species’ range, suggesting that perfume evolution may be tied to the remarkably high number of orchid bee species coexisting together in some neotropical communities. Finally, sister-pair comparisons were consistent with both rapid divergence at speciation and character displacement upon secondary contact. Together, our results provide new insight into the macroevolution of sexual signalling in insects.理论预测，稳定选择（stabilising selection）与歧化选择（diversifying selection）共同参与性信号性状的演化：一方面维持物种内通信信号的完整性，另一方面推动不同演化支间的性状分化。然而，针对诸多关键信号性状，学界仍不清楚此类演化动力是否会催生可预测的宏观进化特征（macroevolutionary signatures）。本研究以新热带区兰蜂——一类因化学性通信被广泛研究的类群——的香水信号为对象，检验是否存在符合性信号理论的宏观进化模式。研究结果显示，相较于非信号性状，兰蜂的香水信号兼具极高的物种特异性与较快的演化速率。香水复杂度与物种分布范围内的同属物种（congeners）数量呈显著正相关，这表明香水演化或与某些新热带区群落中大量共存的兰蜂物种密切相关。最后，姐妹类群比对（sister-pair comparisons）结果同时符合物种形成时的快速分化以及二次接触后的性状替换（character displacement）两种模式。综上，本研究为昆虫性信号的宏观演化提供了全新的认知视角。