Conflicting relationships have been found between diversification rate and temperature across disparate clades of life. Here, we use a supermatrix comprising nearly 20,000 species of rosids—a clade of ~25% of all angiosperm species—to understand global patterns of diversification and its climatic association. Our approach incorporates historical global temperature, assessment of species’ temperature niche, and two broad-scale characterizations of tropical versus non-tropical niche occupancy. We find the diversification rates of most subclades dramatically increased over the last 15 million years (Myr) during cooling associated with global expansion of temperate habitats. Climatic niche is negatively associated with diversification rates, with tropical rosids forming older communities and experiencing speciation rates ~2-fold below rosids in cooler climates. Our results suggest long-term cooling had a disproportionate effect on non-tropical diversification rates, leading to dynamic young communities outside of the tropics, while relative stability in tropical climes led to older, slower-evolving but still species-rich communities.

已经发现不同生命进化枝的多样化率和温度之间存在冲突关系。在这里，我们使用一个包含近 20,000 种蔷薇的超级基质——约占所有被子植物物种的 25% 的进化枝——来了解全球多样化模式及其气候关联。我们的方法结合了历史全球温度、物种温度生态位的评估以及热带与非热带生态位占用的两个大尺度特征。我们发现，在过去 1500 万年 (Myr) 中，在与全球温带栖息地扩张相关的降温过程中，大多数子进化枝的多样化率显着增加。气候生态位与多样化率呈负相关，热带玫瑰形成较老的群落，并且在较冷的气候中经历的物种形成率比玫瑰低约 2 倍。我们的研究结果表明，长期降温对非热带多样化率产生了不成比例的影响，导致热带以外的年轻社区充满活力，而热带气候的相对稳定性导致更老、发展缓慢但仍然物种丰富的社区。