S12-Modeltests.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.

人们假设，在亚洲不同脊椎动物支系中反复演化出滑翔能力，其触发因素是东南亚热带森林中高大龙脑香树（dipterocarp）的主导地位。这些龙脑香森林既是滑翔脊椎动物的多样化中心与气候避难所，同时维系了它们现存的绝大多数物种多样性。我们预测龙脑香树与滑翔脊椎动物的多样化模式存在相似性，并专门检验了这两类群中诸如多样化速率转移或大规模灭绝等偶发多样化事件是否在时间上重合。我们分析了亚洲龙脑香科、来自不同脊椎动物纲的物种最丰富的滑翔类群（包括飞蜥属（Draco）蜥蜴、滑翔蛙以及鼯鼠族（Pteromyini）松鼠）的重建时间树（timetree）所反映的多样化模式，并将其与东南亚地区非滑翔近亲类群（包括攀蜥属（Diploderma）蜥蜴、湍蛙属（Philautus）蛙以及松鼠亚科（Callosciurinae）松鼠）的同等规模演化支进行了对比分析。我们发现，在上新世-更新世（Pliocene–Pleistocene）期间，龙脑香科与滑翔脊椎动物的净多样化速率出现了显著下降，而非滑翔类群则未观测到该现象。我们据此得出结论，这些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学关联。此外，我们提出，尽管龙脑香科的多样化衰退是由亚洲中新世后的干旱化所引发，但滑翔脊椎动物所面临的生存危机则是由上述两类事件共同诱发的。