Can sensory drive explain the evolution of visual signal diversity in terrestrial species? A test with Anolis lizards

Animal signal colors evolve to efficiently stimulate conspecific visual systems. The sensory drive hypothesis proposes that species differences in habitat light conditions favor the evolution of color diversity. The strongest support comes from aquatic systems, while terrestrial systems offer fewer convincing examples. Anolis lizards occupy diverse habitats and signal with a colorful dewlap. Dewlap visibility depends on perceived chromatic contrast with the background. Visual-system modeling has shown that red dewlaps are most visible in most habitat types. However, a majority of species possess white or yellow dewlaps. In a recent behavioral study we showed that low light conditions can sometimes make yellow and white colors more visible, by altering chromatic contrast perception with the background. Using 17 Caribbean Anolis species we showed that cut-on wavelength, a measure of dewlap color in a white-to-red continuum, correlates with habitat light intensity. Pairwise comparisons rev...动物的信号色彩演化出可高效刺激同类视觉系统的特性。感官驱动假说（sensory drive hypothesis）提出，不同物种所处生境的光照条件差异会促进色彩多样性的演化。目前该假说的最有力支持证据源自水生系统，而陆生系统中令人信服的例证则较为稀缺。安乐蜥属蜥蜴（Anolis lizards）栖息于多样生境中，依靠色彩艳丽的喉扇（dewlap）传递信号。喉扇的可见性取决于其与背景间可被感知的色彩对比度（chromatic contrast）。视觉系统建模（visual-system modeling）研究显示，红色喉扇在多数生境类型中具备最优可见性。但绝大多数物种的喉扇实际为白色或黄色。在近期的一项行为学研究中，我们证实：低光照环境有时可通过改变背景下的色彩对比度感知，提升黄色与白色喉扇的可见性。本研究以17种加勒比海安乐蜥物种为研究对象，证实了喉扇颜色在白-红色彩连续体中的量化指标——起始波长（cut-on wavelength）——与生境光照强度存在相关性。成对比较研究……