Data from: Color vision varies more among populations than among species of live-bearing fish from South America

Background: Sensory Bias models for the evolution of mate preference place a great emphasis on the role of sensory system variation in mate preferences. However, the extent to which sensory systems vary across- versus within-species remains largely unknown. Here we assessed whether color vision varies in natural locations where guppies (Poecilia reticulata) and their two closest relatives, Poecilia parae and Poecilia picta, occur in extreme sympatry and school together. All three species base mate preferences on male coloration but differ in the colors preferred. Results: Measuring opsin gene expression, we found that within sympatric locations these species have similar color vision and that color vision differed more across populations of conspecifics. In addition, all three species differ across populations in the frequency of the same opsin coding polymorphism that influences visual tuning. Conclusions: Together, this shows sensory systems vary considerably across populations and supports the possibility that sensory system variation is involved in population divergence of mate preference.

研究背景：择偶偏好演化的感官偏向模型（Sensory Bias models）极为强调感官系统变异在择偶偏好形成中的核心作用。然而，学界目前对感官系统在物种间与物种内的变异程度仍知之甚少。本研究针对孔雀鱼（Poecilia reticulata）及其两个近缘种——饰纹花鳉（Poecilia parae）与彩绘花鳉（Poecilia picta）——在极端同域分布且一同群游的自然栖息地中，其色视觉是否存在变异展开了评估。三个物种均以雄性体色作为择偶偏好的判定依据，但各自偏好的体色有所不同。
研究结果：通过测定视蛋白基因表达水平，我们发现：在同域分布的栖息地中，这三个物种的色视觉较为相似；而同种不同种群间的色视觉差异反而更为显著。此外，三个物种的种群间均存在同一种影响视觉调谐的视蛋白编码多态性的频率差异。
研究结论：综上，本研究结果表明感官系统在种群间存在显著变异，同时支持了「感官系统变异参与择偶偏好的种群分化」这一可能性。