Am Nat. 2020 Jun;195(6):948-963. doi: 10.1086/708273. Epub 2020 Apr 3.
The causes of the rapid diversification and extraordinary richness of flowering plants (angiosperms) relative to other plant clades is a long-standing mystery. Angiosperms are only one among 10 major land plant clades (phyla) but include ∼90% of land plant species. However, most studies that have tried to identify which traits might explain the remarkable diversification of angiosperms have focused only on richness patterns within angiosperms and tested only one or a few traits at a single hierarchical scale. Here, we assemble a database of 31 diverse traits among 678 families and analyze relationships between traits and diversification rates across all land plants at three hierarchical levels (phylum, order, and family) using phylogenetic multiple regression. We find that most variation (∼85%) in diversification rates among major clades (phyla) is explained by biotically mediated fertilization (e.g., insect pollination) and clade-level geographic range size. Different sets of traits explain diversification at different hierarchical levels, with geographic range size dominating among families. Surprisingly, we find that traits related to local-scale species interactions (i.e., biotic fertilization) are particularly important for explaining diversification patterns at the deepest timescales, whereas large-scale geographic factors (i.e., clade-level range size) are more important at shallower timescales. This dichotomy might apply broadly across organisms.
相对于其他植物类群，开花植物（被子植物）的快速多样化和非凡丰富度的原因一直是个谜。被子植物只是 10 个主要陆地植物类群（门）之一，但包含了约 90%的陆地植物物种。然而，大多数试图确定哪些特征可能解释被子植物显著多样化的研究都只关注于被子植物内部的丰富度模式，并在单个层次尺度上测试了一个或几个特征。在这里，我们在 678 个科中汇集了 31 个不同的特征的数据库，并使用系统发育多元回归分析了所有陆地植物在三个层次（门、目和科）上的特征与多样化率之间的关系。我们发现，主要类群（门）之间的多样化率的大部分变异（约 85%）是由生物介导的受精（例如，昆虫授粉）和类群水平的地理范围大小解释的。不同的特征集在不同的层次上解释多样化，地理范围大小在科中占主导地位。令人惊讶的是，我们发现与局部物种相互作用（即生物受精）相关的特征对于解释最深远时间尺度上的多样化模式尤为重要，而大尺度地理因素（即类群水平的范围大小）在较浅的时间尺度上更为重要。这种二分法可能广泛适用于生物体。
