S11-RevBayes_analyses.R from Their fates intertwined: diversification patterns of the Asian gliding vertebrates may have been forged by dipterocarp trees

The repeated evolution of gliding in diverse Asian vertebrate lineages is hypothesized to have been triggered by the dominance of tall dipterocarp trees in the tropical forests of Southeast Asia. These dipterocarp forests have acted as both centres of diversification and climatic refugia for gliding vertebrates, and support most of their extant diversity. We predict similarities in the diversification patterns of dipterocarp trees and gliding vertebrates, and specifically test whether episodic diversification events such as rate shifts and/or mass extinctions were temporally congruent in these groups. We analysed diversification patterns in reconstructed timetrees of Asian dipterocarps, the most speciose gliding vertebrates from different classes (Draco lizards, gliding frogs and Pteromyini squirrels) and compared them with similar-sized clades of non-gliding relatives (Diploderma lizards, Philautus frogs and Callosciurinae squirrels) from Southeast Asia. We found significant declines in net-diversification rates of dipterocarps and the gliding vertebrates during the Pliocene–Pleistocene, but not in the non-gliding groups. We conclude that the homogeneity and temporal coincidence of these rate declines point to a viable ecological correlation between dipterocarps and the gliding vertebrates. Further, we suggest that while the diversification decay in dipterocarps was precipitated by post-Miocene aridification of Asia, the crises in the gliding vertebrates were induced by both events concomitantly.

学界假说提出，东南亚热带森林中高大龙脑香树（dipterocarp trees）的主导地位，驱动了亚洲不同脊椎动物支系内滑翔行为的多次独立演化。此类龙脑香林既是滑翔脊椎动物的多样化中心与气候避难所，同时承载了该类群绝大多数现生多样性。本研究预测龙脑香树与滑翔脊椎动物的多样化模式存在相似性，并针对性检验了两类群中演化速率转移、大规模灭绝等间断性多样化事件是否在时间上具有一致性。本研究对亚洲龙脑香树、以及不同类群中物种丰富度最高的滑翔脊椎动物（飞蜥属Draco蜥蜴、滑翔蛙类与鼯鼠族Pteromyini松鼠）的重建时间树开展多样化模式分析，并与东南亚地区非滑翔近缘类群（龙蜥属Diploderma蜥蜴、小树蛙属Philautus蛙类与丽松鼠亚科Callosciurinae松鼠）的等规模演化支进行对比。本研究发现，在上新世-更新世（Pliocene–Pleistocene）时期，龙脑香树与滑翔脊椎动物的净多样化速率均出现显著下降，而非滑翔类群则未观察到该现象。本研究认为，此类速率下降的同质性与时间重合性，表明龙脑香树与滑翔脊椎动物之间存在可靠的生态关联。此外，本研究提出，尽管龙脑香树的多样化衰退由亚洲中新世（Miocene）后的干旱化所驱动，但滑翔脊椎动物所面临的生存危机则是由这两类事件共同诱发的。