PDF(Pubmed)
Abstract：
The expression of sexually selected traits, such as ornaments or body coloration, is often influenced by environmental conditions. While such phenotypic plasticity is often thought to precede evolutionary change, plasticity itself can also be a target of selection. However, the selective forces supporting the evolution and persistence of plasticity in sexual traits are often unclear. Using the cichlid fish Astatotilapia burtoni, we show that variation in the level of mate competition may promote plasticity in body coloration. In this species, males can change between yellow and blue colour. We found that experimentally increased competition over mating territories led to a higher proportion of males expressing the yellow phenotype. The expression of yellow coloration was found to be beneficial because yellow males won more staged dyadic contests and exhibited a lower level of oxidative stress than blue males. However, females were more likely to spawn with blue males in mate choice experiments, suggesting that expression of blue coloration is sexually more attractive. The ability to adjust colour phenotype according to the local competitive environment could therefore promote the persistence of plasticity in coloration.
摘要：
性选择特征的表达，如装饰品或身体着色，通常受环境条件的影响。虽然这种表型可塑性通常被认为是在进化变化之前，可塑性本身也可以是选择的目标。然而,支持性特征可塑性进化和持久性的选择性力量通常不清楚。使用丽鱼科鱼，我们表明，配偶竞争水平的变化可能会促进身体颜色的可塑性。在这个物种中,男性可以在黄色和蓝色之间变化。我们发现，在交配区域上通过实验增加的竞争导致表达黄色表型的雄性比例更高。发现黄色的表达是有益的，因为黄色雄性比蓝色雄性赢得了更多的二进竞赛，并且表现出更低的氧化应激水平。然而,在择偶实验中，雌性更有可能与蓝色雄性产卵，这表明蓝色的表达在性方面更具吸引力。因此，根据局部竞争环境调整颜色表型的能力可以促进着色可塑性的持久性。
