Mountain systems harbor a substantial fraction of global biodiversity and, thus, provide excellent opportunities to study rapid diversification and to understand the historical processes underlying the assembly of biodiversity hotspots. The rich biodiversity in mountains is widely regarded as having arisen under the influence of geological and climatic processes as well as the complex interactions among them. However, the relative contribution of geology and climate in driving species radiation is seldom explored. Here, we studied the evolutionary radiation of Oreocharis (Gesneriaceae), which has diversified extensively throughout East Asia, especially within the Hengduan Mountains (HDM), using transcriptomic data and a time calibrated phylogeny for 88% (111/126) of all species of the genus. In particular, we applied phylogenetic reconstructions to evaluate the extent of incomplete lineage sorting accompanying the early and rapid radiation in the genus. We then fit macroevolutionary models to explore its spatial and diversification dynamics in Oreocharis and applied explicit birth–death models to investigate the effects of past environmental changes on its diversification. Evidence from 574 orthologous loci suggest that Oreocharis underwent an impressive early burst of speciation starting ca. 12 Ma in the Miocene, followed by a drastic decline in speciation toward the present. Although we found no evidence for a shift in diversification rate across the phylogeny of Oreocharis, we showed a difference in diversification dynamics between the HDM and non-HDM lineages, with higher diversification rates in the HDM. The diversification dynamic of Oreocharis is most likely positively associated with temperature-dependent speciation and dependency on the Asian monsoons. We suggest that the warm and humid climate of the mid-Miocene was probably the primary driver of the rapid diversification in Oreocharis, while mountain building of the HDM might have indirectly affected species diversification of the HDM lineage. This study highlights the importance of past climatic changes, combined with mountain building, in creating strong environmental heterogeneity and driving diversification of mountain plants, and suggests that the biodiversity in the HDM cannot directly be attributed to mountain uplift, contrary to many recent speculations.[East Asian monsoons; environmental heterogeneity; Hengduan Mountains; incomplete lineage sorting; Oreocharis; past climate change; rapid diversification; transcriptome.]

中文翻译：

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中新世植物属爆炸性辐射的系统发育和宏观进化证据

山地系统拥有全球生物多样性的很大一部分，因此为研究快速多样化和了解生物多样性热点聚集的历史过程提供了极好的机会。山区丰富的生物多样性被广泛认为是在地质和气候过程以及它们之间复杂相互作用的影响下产生的。然而，很少探索地质和气候在驱动物种辐射中的相对贡献。在这里，我们使用转录组数据和时间校准的系统发育对所有物种的 88% (111/126) 进行了研究。属。尤其是，我们应用系统发育重建来评估伴随该属早期和快速辐射的不完全谱系分类的程度。然后，我们拟合宏观进化模型以探索其在 Oreocharis 中的空间和多样化动态，并应用显式生死模型来研究过去环境变化对其多样化的影响。来自 574 个直系同源基因座的证据表明，Oreocharis 经历了令人印象深刻的早期物种形成爆发，开始于 ca。中新世 12 Ma，随后物种形成向现在急剧下降。虽然我们没有发现任何证据表明 Oreocharis 系统发育的多样化率发生变化，但我们发现 HDM 和非 HDM 谱系之间的多样化动态存在差异，HDM 的多样化率更高。Oreocharis 的多样化动态很可能与温度依赖性物种形成和对亚洲季风的依赖性呈正相关。我们认为中新世中期温暖潮湿的气候可能是 Oreocharis 快速多样化的主要驱动力，而 HDM 的造山可能间接影响了 HDM 谱系的物种多样化。这项研究强调了过去的气候变化与造山相结合，在造成强烈的环境异质性和推动山区植物多样化方面的重要性，并表明 HDM 中的生物多样性不能直接归因于山区隆起，这与最近的许多推测相反。 [东亚季风；环境异质性；横断山脉；不完整的血统排序；奥利奥查里斯；过去的气候变化；快速多样化；转录组。]