Data from: Identifying hidden rate changes in the evolution of a binary morphological character: the evolution of plant habit in Campanulid angiosperms

The growth of phylogenetic trees in scope and in size is promising from the standpoint of understanding a wide variety of evolutionary patterns and processes. With trees comprised of larger, older, and globally distributed clades, it is likely that the lability of a binary character will differ significantly among lineages, which could lead to errors in estimating transition rates and the associated inference of ancestral states. Here we develop and implement a new method for identifying different rates of evolution in a binary character along different branches of a phylogeny. We illustrate this approach by exploring the evolution of growth habit in Campanulidae, a flowering plant clade containing some 35,000 species. The distribution of woody versus herbaceous species calls into question the use of traditional models of binary character evolution. The recognition and accommodation of changes in the rate of growth form evolution in different lineages demonstrates, for the first time, a robust picture of growth form evolution across a very large, very old, and very widespread flowering plant clade.

从解析多样演化模式与演化过程的视角出发，系统发育树（phylogenetic tree）在研究范围与规模上的拓展极具应用前景。当研究对象为涵盖更大类群、更古老类群且全球分布的系统发育树时，二元性状（binary character）的演化易变性很可能在不同演化支系间存在显著差异，这可能会导致状态转换速率估算以及相关祖先状态推断出现偏差。本研究开发并实现了一种全新方法，可用于识别系统发育树不同分支上二元性状的进化速率差异。我们以包含约35000个物种的被子植物类群桔梗类（Campanulidae）的生长型演化为例，对该方法进行了实例演示。木本与草本物种的分布格局，使得传统二元性状进化模型的适用性受到了质疑。本次研究识别并整合了不同演化支系中生长型进化速率的变化，首次为这个规模庞大、起源古老且分布广泛的被子植物类群构建了稳健的生长型演化图景。