Into the light: diurnality has evolved multiple times in geckos

Geckos are the only major lizard group consisting mostly of nocturnal species. Nocturnality is presumed to have evolved early in gecko evolution and geckos possess numerous adaptations to functioning in low light and at low temperatures. However, not all gecko species are nocturnal and most diurnal geckos have their own distinct adaptations to living in warmer, sunlit environments. We reconstructed the evolution of gecko activity patterns using a newly generated time-calibrated phylogeny. Our results provide the first phylogenetic analysis of temporal activity patterns in geckos and confirm an ancient origin of nocturnality at the root of the gecko tree. We identify multiple transitions to diurnality at a variety of evolutionary time scales and transitions back to nocturnality occur in several predominantly diurnal clades. The scenario presented here will be useful in reinterpreting existing hypotheses of how geckos have adapted to varying thermal and light environments. These results c...壁虎类（Geckos）是唯一一类以夜行性物种为主体的大型蜥蜴类群。学界普遍推测，夜行性习性（nocturnality）在壁虎类的演化早期便已起源，且壁虎类演化出了诸多适应低光照与低温环境的适应性特征。然而并非所有壁虎物种均为夜行性，多数昼行性（diurnal）壁虎也演化出了各自独特的适应性性状，以适应温暖且光照充足的生存环境。本研究借助全新构建的时间校准系统发育树（time-calibrated phylogeny），重构了壁虎类活动模式的演化历程。本研究结果首次针对壁虎类的时间活动模式开展了系统发育分析，并证实了夜行性习性在壁虎类演化树根部便已存在的古老起源。研究团队发现，在不同的演化时间尺度上，壁虎类多次发生了向昼行性习性（diurnality）的转换；同时在多个以昼行性物种为主的演化支（clades）中，也存在着从昼行性转回夜行性的演化事件。本研究所提出的演化场景，将有助于重新解读此前关于壁虎类如何适应不同温度与光照环境的相关假说。本研究结果可为...