Rates of climatic niche evolution vary widely across the tree of life and are strongly associated with rates of diversification among clades. However, why the climatic niche evolves more rapidly in some clades than others remains unclear. Variation in life history traits often plays a key role in determining the environmental conditions under which species can survive, and therefore, could impact the rate at which lineages can expand in available climatic niche space. Here, we explore the relationships among life-history variation, climatic niche breadth, and rates of climatic niche evolution. We reconstruct a phylogeny for the genus Desmognathus, an adaptive radiation of salamanders distributed across eastern North America, based on nuclear and mitochondrial genes. Using this phylogeny, we estimate rates of climatic niche evolution for species with long, short, and no aquatic larval stage. Rates of climatic niche evolution are unrelated to the mean climatic niche breadth of species with different life histories. Instead, we find that the evolution of a short larval period promotes greater exploration of climatic space, leading to increased rates of climatic niche evolution across species having this trait. We propose that morphological and physiological differences associated with variation in larval stage length underlie the heterogeneous ability of lineages to explore climatic niche space. Rapid rates of climatic niche evolution among species with short larval periods were an important dimension of the clade's adaptive radiation and likely contributed to the rapid rate of lineage accumulation following the evolution of an aquatic life history in this clade. Our results show how variation in a key life-history trait can constrain or promote divergence of the climatic niche, leading to variation in rates of climatic niche evolution among species. This article is protected by copyright. All rights reserved.

中文翻译：

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发育生活史与蝾螈适应性辐射中气候生态位进化率的变化有关

整个生命树的气候生态位进化速率差异很大，并且与进化枝之间的多样化速率密切相关。然而，为什么某些进化枝中的气候生态位比其他进化枝进化得更快仍不清楚。生活史特征的变化通常在确定物种能够生存的环境条件方面起着关键作用，因此，可能会影响谱系在可用气候生态位空间中扩展的速度。在这里，我们探讨了生活史变异、气候生态位宽度和气候生态位演化速率之间的关系。我们基于核和线粒体基因重建了 Desmognathus 属的系统发育，这是一种分布在北美东部的蝾螈的适应性辐射。使用这种系统发育，我们估计了具有长、短和无水生幼虫阶段的物种的气候生态位进化率。气候生态位演化速率与不同生活史物种的平均气候生态位宽度无关。相反，我们发现短幼虫期的进化促进了对气候空间的更大探索，导致具有这种特征的物种的气候生态位进化率增加。我们提出，与幼虫阶段长度变化相关的形态和生理差异是谱系探索气候生态位空间的异质能力的基础。幼虫期较短的物种之间气候生态位进化的快速速率是进化枝的一个重要维度' s 适应性辐射，并可能促成了该进化枝中水生生物历史演变后谱系积累的快速速度。我们的结果显示了关键生活史特征的变化如何限制或促进气候生态位的分化，导致物种间气候生态位进化率的变化。本文受版权保护。版权所有。