Data from: Synergistic selection regimens drive the evolution of display complexity in birds of paradise

1. Integrated visual displays that combine gesture with color are nearly ubiquitous in the animal world, where they evolve in response to sexual selection for their role in courtship and competition. However, few studies examine how multiple selection regimens shape each component of these complex phenotypes on a macroevolutionary scale. 2. Here we study this issue by assessing how both sexual and ecological selection work together to influence visual display complexity in the birds of paradise. 3. We first find that sexual dichromatism is highest in lekking species, which undergo more intense sexual selection by female choice than non-lekking species. Meanwhile, species in which males directly compete with one another at communal display courts have more carotenoid-based ornaments and fewer melanin ornaments. 4. Meanwhile, display habitat influences gestural complexity. Species that dance in the cluttered understory have more complex dances than canopy-displaying species. 5. Taken together, our results illustrate how distinct selection regimens each operate on individual elements comprising a complex display. This supports a modular model of display evolution, wherein the ultimate integrated display is the product of synergy between multiple factors that select for different types of phenotypic complexity.

1. 整合了肢体动作与色彩的复合型视觉展示在动物界几乎无处不在，这类展示因在求偶与种内竞争中扮演重要角色，而在性选择（sexual selection）的驱动下发生演化。然而，目前鲜有研究在宏观演化尺度下，探究多重选择机制如何塑造这类复杂表型的各个组成部分。
2. 本研究以极乐鸟（birds of paradise）为研究类群，通过解析性选择与生态选择的协同作用如何影响其视觉展示复杂度，对上述问题展开系统性探讨。
3. 本研究首先发现，采用求偶场交配制度的物种具有最高的雌雄体色二型性（sexual dichromatism），这类物种相较于非求偶场物种，承受着更强的由雌性选择介导的性选择压力。同时，雄性会在公共展示场直接展开种内竞争的物种，其类胡萝卜素依赖型饰羽更为丰富，而黑色素依赖型饰羽则相对较少。
4. 此外，展示生境同样会对动作展示复杂度产生显著影响：在植被茂密的林下层进行舞蹈展示的物种，其舞蹈复杂度显著高于在树冠层开展展示的物种。
5. 综合来看，本研究结果清晰阐明了不同的选择机制如何分别作用于复合型视觉展示的各个组成要素，这一发现支持了展示演化的模块化模型：即最终形成的整合式视觉展示，是多个选择不同类型表型复杂度的因子协同作用的产物。