• Leaf reflectance spectra have been increasingly used to assess plant diversity. However, we do not yet understand how spectra vary across the tree of life or how the evolution of leaf traits affects the differentiation of spectra among species and lineages.
• Here we describe a framework that integrates spectra with phylogenies and apply it to a global dataset of over 16 000 leaf‐level spectra (400–2400 nm) for 544 seed plant species. We test for phylogenetic signal in spectra, evaluate their ability to classify lineages, and characterize their evolutionary dynamics.
• We show that phylogenetic signal is present in leaf spectra but that the spectral regions most strongly associated with the phylogeny vary among lineages. Despite among‐lineage heterogeneity, broad plant groups, orders, and families can be identified from reflectance spectra. Evolutionary models also reveal that different spectral regions evolve at different rates and under different constraint levels, mirroring the evolution of their underlying traits.
• Leaf spectra capture the phylogenetic history of seed plants and the evolutionary dynamics of leaf chemistry and structure. Consequently, spectra have the potential to provide breakthrough assessments of leaf evolution and plant phylogenetic diversity at global scales.

中文翻译：

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叶反射光谱捕捉种子植物的进化历史。

• 叶反射光谱已越来越多地用于评估植物多样性。然而，我们还不了解光谱在生命之树中是如何变化的，或者叶子性状的进化如何影响物种和谱系之间光谱的分化。
• 在这里，我们描述了一个将光谱与系统发育相结合的框架，并将其应用于 544 种种子植物物种的超过 16000 个叶级光谱（400-2400 nm）的全球数据集。我们测试光谱中的系统发育信号，评估它们对谱系进行分类的能力，并描述它们的进化动态。
• 我们表明系统发育信号存在于叶光谱中，但与系统发育最密切相关的光谱区域在谱系之间​​有所不同。尽管谱系间存在异质性，但可以从反射光谱中识别出广泛的植物群、目和科。进化模型还揭示了不同的光谱区域以不同的速率和不同的约束水平进化，反映了它们潜在特征的进化。
• 叶光谱捕获种子植物的系统发育历史以及叶化学和结构的进化动力学。因此，光谱有可能在全球范围内提供对叶片进化和植物系统发育多样性的突破性评估。