PREMISE Events of accelerated species diversification represent one of Earth's most celebrated evolutionary outcomes. Northern Andean high-elevation ecosystems, or páramos, host some plant lineages that have experienced the fastest diversification rates, likely triggered by ecological opportunities created by mountain uplifts, local climate shifts, and key trait innovations. However, the mechanisms behind rapid speciation into the new adaptive zone provided by these opportunities have long remained unclear. METHODS We address this issue by studying the Venezuelan clade of Espeletia, a species-rich group of páramo-endemics showing a dazzling ecological and morphological diversity. We performed several comparative analyses to study both lineage and trait diversification, using an updated molecular phylogeny of this plant group. RESULTS We showed that sets of either vegetative or reproductive traits have conjointly diversified in Espeletia along different vegetation belts, leading to adaptive syndromes. Diversification in vegetative traits occurred earlier than in reproductive ones. The rate of species and morphological diversification showed a tendency to slow down over time, probably due to diversity dependence. We also found that closely related species exhibit significantly more overlap in their geographic distributions than distantly related taxa, suggesting that most events of ecological divergence occurred at close geographic proximity within páramos. CONCLUSIONS These results provide compelling support for a scenario of small-scale ecological divergence along multiple ecological niche dimensions, possibly driven by competitive interactions between species, and acting sequentially over time in a leapfrog pattern.

中文翻译：

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埃斯佩莱蒂亚生态分化和跨越式适应性辐射的系统发育特征

加速物种多样化的前提事件代表了地球上最著名的进化成果之一。北安第斯高海拔生态系统或帕拉莫斯拥有一些经历了最快多样化速度的植物谱系，这可能是由山脉隆起、当地气候变化和关键性状创新创造的生态机会引发的。然而，由这些机会提供的快速物种形成进入新适应区的机制长期以来一直不清楚。方法我们通过研究委内瑞拉的 Espeletia 分支来解决这个问题，Espeletia 是一个物种丰富的 páramo 地方性群，显示出令人眼花缭乱的生态和形态多样性。我们使用该植物群的更新分子系统发育进行了几项比较分析，以研究谱系和性状多样化。结果我们发现，在 Espeletia 中，沿着不同的植被带，营养或繁殖性状组合多样化，导致适应性综合征。营养性状的多样化发生早于生殖性状。物种和形态多样化的速度显示出随着时间的推移而放缓的趋势，可能是由于多样性依赖性。我们还发现，密切相关的物种在地理分布上的重叠明显多于远缘关系的分类群，这表明大多数生态差异事件发生在帕拉莫斯岛内的地理距离很近的地方。结论这些结果为沿着多个生态位维度的小规模生态分化的情景提供了令人信服的支持，这可能是由物种之间的竞争相互作用驱动的，