Climatic and topographic changes during the Quaternary have driven the development of high biodiversity in mountain areas. However, the effects of niche evolution on the diversification patterns of plant species under rapid habitat changes are still unknown.
Yamamoto et al. use biogeographic analysis and macro-evolutionary modeling to examine the diversification history of Primula sect. Reinii (Primulaceae) endemic to the Japanese Archipelago. Heterogeneous climatic niche optima and rates were found in the closely related species. The authors infer that spatiotemporal heterogeneity in the archipelago and climatic niche evolution may play a significant role in the biogeographic history and species’ diversification patterns.