Data from: Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity

Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction), and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years.为何部分性状及性状组合在生命之树（tree of life）中极为常见，而另一些却极其罕见？某一演化支（clade）内的性状多样性分布，在任意时刻均取决于该支系的祖先性状状态、新表型的演化速率、不同谱系间的物种形成与灭绝速率差异，以及是否达到演化平衡状态。本研究聚焦被子植物（angiosperms）这一演化支——其因部分性状组合丰度颇高、另一些则极为罕见而广为人知——探讨了性状转换速率、差异化分化（speciation minus extinction，即物种形成速率减去灭绝速率）以及非平衡动力学在其演化历史中的作用。本研究分析显示，三种性状状态（具花冠（corolla）、两侧对称（bilateral symmetry）、雄蕊数目减少（reduced stamen number））可作为关键创新（key innovation）协同发挥作用，使携带该组合的谱系的分化速率提升一倍。然而，当前该组合的出现频率却低于演化平衡状态下的预测值，原因在于构成该组合的单个性状的演化频率极低。模拟实验结果表明，在未来相当长的时期内，被子植物的性状状态频率仍将远偏离平衡状态。当重大创新的演化频率极低时，这类非平衡动力学现象可能较为普遍：携带祖先性状形式的谱系能够存续数千万年，其数量甚至超过携带提升分化速率性状的谱系。