The fact that angiosperms are so species‐rich and ecologically diverse – Darwin’s second abominable mystery – could be explained by their ability to ‘reinvent’ themselves by evolving functional traits repeatedly over time, space and taxonomic clades. These trait innovations may facilitate adaptation and increase diversification rates. In this article, I quantify this ‘trait flexibility’ by reviewing the literature on trait transition rates and trait‐dependent diversification rates in angiosperms and their extant sister clade, acrogymnosperms. I show that angiosperms indeed evolved elevated trait transition and trait‐dependent diversification rates compared to gymnosperms, and rates are highest within species‐rich angiosperm orders (e.g. Fabales, Lamiales). The (genetic) ability of certain angiosperm lineages to repeatedly evolve adaptive traits may have facilitated sustained high net diversification resulting from numerous episodic radiations.

中文翻译：

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达尔文的第二个“令人难以置信的谜”：特质灵活性作为导致被子植物多样性的创新。

被子植物物种丰富且生态多样-这是达尔文的第二个可恶的奥秘-可以解释为，被子植物通过随着时间，空间和生物分类进化反复地进化功能性特征来“重塑”自身的能力可以解释这一事实。这些特质创新可以促进适应并提高多元化率。在本文中，我通过回顾有关被子植物及其现存姐妹枝顶生子植物中性状转化率和性状依赖性多样化率的文献来量化这种“性状灵活性”。我发现与被子植物相比，被子植物确实进化出更高的性状转变和与性状相关的多样化速率，并且在物种丰富的被子植物订单（例如Fabales，Lamiales）中，其发生率最高。