Data from: Unraveling the determinants of insular body size shifts

The island rule, a pattern of size shifts on islands, is an oft-cited but little understood phenomenon of evolutionary biology. Here we explore the evolutionary mechanisms behind the rule in 184 mammal species, testing climatic, ecological, and phylogenetic hypotheses in a robust quantitative framework. Our findings confirm the importance of species’ ecological traits in determining both the strength and the direction of body size changes on islands. Although the island rule pattern appears relatively weak overall, we find strongest support for models incorporating trait, climatic, and geographic factors in a phylogenetic context, lending support to the idea that the island rule is a complex phenomenon driven by interacting intrinsic and extrinsic mechanisms. Overall we find that different clades may be evolutionarily predisposed to dwarfism or gigantism but the magnitude of size changes depends more on adaptation to the local environment.

岛屿法则（island rule）是描述岛屿物种体型变化的经典模式，同时也是进化生物学领域被广泛引述却鲜有深入解析的现象。本研究针对184种哺乳动物，探究岛屿法则背后的进化机制，在严谨的定量分析框架下，对气候、生态与系统发育（phylogenetic）相关假说开展系统性检验。研究结果证实，物种的生态特征在决定岛屿体型变化的强度与方向上均发挥着关键作用。尽管整体而言岛屿法则的模式相对微弱，但本研究发现，纳入物种性状、气候与地理因素的系统发育模型获得了最强的支持证据，这为“岛屿法则是由内在与外在机制协同作用驱动的复杂进化现象”这一观点提供了有力佐证。总体来看，不同演化支（clade）在进化层面或更易倾向于体型矮化或巨型化，但体型变化的幅度更多取决于对当地生境的适应性调整。