Aim Mountains and islands are both well known for their high endemism. To explain this similarity, parallels have been drawn between the insularity of “true islands” (land surrounded by water) and the isolation of habitats within mountains (so‐called “mountain islands”). However, parallels rarely go much beyond the observation that mountaintops are isolated from one another, as are true islands. Here, we challenge the analogy between mountains and true islands by re‐evaluating the literature, focusing on isolation (the prime mechanism underlying species endemism by restricting gene flow) from a dynamic perspective over space and time. Framework We base our conceptualization of “isolation” on the arguments that no biological system is completely isolated; instead, isolation has multiple spatial and temporal dimensions relating to biological and environmental processes. We distinguish four key dimensions of isolation: (a) environmental difference from surroundings; (b) geographical distance to equivalent environment [points (a) and (b) are combined as “snapshot isolation”]; (c) continuity of isolation in space and time; and (d) total time over which isolation has been present [points (c) and (d) are combined as “isolation history”]. We evaluate the importance of each dimension in different types of mountains and true islands, demonstrating that substantial differences exist in the nature of isolation between and within each type. In particular, different types differ in their initial isolation and in the dynamic trajectories they follow, with distinct phases of varying isolation that interact with species traits over time to form present‐day patterns of endemism. Conclusions Our spatio‐temporal definition of isolation suggests that the analogy between true islands and mountain islands masks important variation of isolation over long time‐scales. Our understanding of endemism in isolated systems can be greatly enriched if the dynamic spatio‐temporal dimensions of isolation enter models as explanatory variables and if these models account for the trajectories of the history of a system.

中文翻译：

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快照隔离和隔离历史挑战用于理解特有现象的山脉和岛屿之间的类比

艾姆山脉和岛屿都以其特有的高度而闻名。为了解释这种相似性，人们将“真正的岛屿”（被水包围的土地）的孤立性与山区栖息地的孤立性（所谓的“山岛”）进行了比较。然而，相似之处很少超出山顶彼此孤立的观察结果，真正的岛屿也是如此。在这里，我们通过重新评估文献来挑战山脉和真正岛屿之间的类比，从空间和时间的动态角度关注隔离（通过限制基因流动的物种特有现象的主要机制）。框架 我们的“隔离”概念基于没有生物系统是完全隔离的论点。反而，隔离具有与生物和环境过程相关的多个空间和时间维度。我们区分了隔离的四个关键维度：(a) 环境与周围环境的差异；(b) 到等效环境的地理距离[点 (a) 和 (b) 合并为“快照隔离”]；(c) 空间和时间隔离的连续性；(d) 存在隔离的总时间[点 (c) 和 (d) 合并为“隔离历史”]。我们评估了不同类型山脉和真实岛屿中每个维度的重要性，表明每种类型之间和内部的隔离性质存在重大差异。特别是，不同类型的初始隔离和它们遵循的动态轨迹不同，具有不同隔离的不同阶段，随着时间的推移与物种特征相互作用，形成当今的特有模式。结论我们对隔离的时空定义表明，真正的岛屿和山岛之间的类比掩盖了隔离在长时间尺度上的重要变化。如果隔离的动态时空维度作为解释变量进入模型，并且如果这些模型解释了系统历史的轨迹，我们对隔离系统中特有现象的理解就会得到极大的丰富。