S10-treepar_analyses.R.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 (<i>Draco</i> lizards, gliding frogs and Pteromyini squirrels) and compared them with similar-sized clades of non-gliding relatives (<i>Diploderma</i> lizards, <i>Philautus</i> 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.

学界假说认为，东南亚热带森林中高大龙脑香科（dipterocarp）乔木的主导地位，驱动了亚洲多样脊椎动物支系反复演化出滑翔能力。这类龙脑香森林不仅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存物种多样性。

本研究预测龙脑香科植物与滑翔脊椎动物的演化模式存在相似性，并专门检验这两类群的间断性演化事件（如演化速率转移或集群灭绝）是否在时间上具有一致性。我们对亚洲龙脑香科植物、以及来自不同纲的物种丰富度最高的滑翔脊椎动物类群（包括飞蜥属*Draco*蜥蜴、滑翔蛙与鼯鼠族Pteromyini松鼠）的重建时间树开展了演化模式分析，并将其与东南亚地区非滑翔近亲类群的同等规模演化支（包括攀蜥属*Diploderma*蜥蜴、小树蛙属*Philautus*蛙类与松鼠亚科Callosciurinae松鼠）进行对比。

研究发现，在上新世-更新世时期，龙脑香科植物与滑翔脊椎动物的净演化速率均出现显著下降，而非滑翔类群则无此现象。本研究认为，两类群演化速率下降的同质性与时间重合性，表明龙脑香科植物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：龙脑香科植物的演化衰退由亚洲中新世后的干旱化所驱动，而滑翔脊椎动物所面临的生存危机则是这两类事件共同作用的结果。