Department of Environmental Science, Institute for Wetland and Water Research, Radboud University, Nijmegen, The Netherlands.
Integrative Ecology Group, Estación Biológica de Doñana, Spanish National Research Council (CSIC), Sevilla, Spain.
Nat Ecol Evol. 2021 Jun;5(6):768-786. doi: 10.1038/s41559-021-01426-y. Epub 2021 Apr 15.
Island faunas can be characterized by gigantism in small animals and dwarfism in large animals, but the extent to which this so-called 'island rule' provides a general explanation for evolutionary trajectories on islands remains contentious. Here we use a phylogenetic meta-analysis to assess patterns and drivers of body size evolution across a global sample of paired island-mainland populations of terrestrial vertebrates. We show that 'island rule' effects are widespread in mammals, birds and reptiles, but less evident in amphibians, which mostly tend towards gigantism. We also found that the magnitude of insular dwarfism and gigantism is mediated by climate as well as island size and isolation, with more pronounced effects in smaller, more remote islands for mammals and reptiles. We conclude that the island rule is pervasive across vertebrates, but that the implications for body size evolution are nuanced and depend on an array of context-dependent ecological pressures and environmental conditions.
岛屿动物区系的特征是小动物的巨型化和大型动物的矮小化，但这种所谓的“岛屿法则”在多大程度上为岛屿上的进化轨迹提供了一般性解释仍存在争议。在这里，我们使用系统发育荟萃分析来评估全球范围内配对的岛屿-大陆陆生脊椎动物种群的体型进化模式和驱动因素。我们表明，“岛屿法则”效应在哺乳动物、鸟类和爬行动物中广泛存在，但在两栖动物中不太明显，两栖动物大多倾向于巨型化。我们还发现，岛屿矮小化和巨型化的幅度受到气候以及岛屿大小和隔离度的影响，对于哺乳动物和爬行动物来说，在较小、较偏远的岛屿上影响更为明显。我们的结论是，岛屿法则在脊椎动物中普遍存在，但对体型进化的影响是微妙的，取决于一系列与上下文相关的生态压力和环境条件。
