Why and how organismal lineages radiate is commonly studied through either assessing abiotic factors (biogeography, geomorphological processes, climate) or biotic factors (traits, interactions). Despite increasing awareness that both abiotic and biotic processes may have important joint effects on diversification dynamics, few attempts have been made to quantify the relative importance and timing of these factors, and their potentially interlinked direct and indirect effects, on lineage diversification. We here combine assessments of historical biogeography, geomorphology, climatic niche, vegetative and floral trait evolution to test whether these factors jointly, or in isolation, explain diversification dynamics of a Neotropical plant clade (Merianieae, Melastomataceae). After estimating ancestral areas and the changes in niche and trait disparity over time, we employ Phylogenetic Path Analyses as a synthesis tool to test eleven hypotheses on the individual direct and indirect effects of these factors on diversification rates. We find strongest support for interlinked effects of colonization of the uplifting Andes during the mid-Miocene and rapid abiotic climatic niche evolution in explaining a burst in diversification rate in Merianieae. Within Andean habitats, later increases in floral disparity allowed for the exploitation of wider pollination niches (i.e., shifts from bee to vertebrate pollinators), but did not affect diversification rates. Our approach of including both vegetative and floral trait evolution, rare in assessments of plant diversification in general, highlights that the evolution of woody habit and larger flowers preceded the colonization of the Andes, but was likely critical in enabling the rapid radiation in montane environments. Overall, and in concert with the idea that ecological opportunity is a key element of evolutionary radiations, our results suggest that a combination of rapid niche evolution and trait shifts were critical for the exploitation of newly available niche space in the Andes in the mid-Miocene. Further, our results emphasize the importance of incorporating both abiotic and biotic factors into the same analytical framework if we aim to quantify the relative and interlinked effects of these processes on diversification.

中文翻译：

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山脉抬升、气候生态位和花性状进化对安第斯植物进化枝多样化动态的连续直接和间接影响


通常通过评估非生物因素（生物地理学、地貌过程、气候）或生物因素（性状、相互作用）来研究生物谱系辐射的原因和方式。尽管人们越来越认识到非生物和生物过程可能对多样化动态产生重要的共同影响，但很少有人尝试量化这些因素的相对重要性和时间安排，以及它们对谱系多样化的潜在相互关联的直接和间接影响。我们在这里结合了对历史生物地理学、地貌学、气候生态位、营养和花卉性状进化的评估，以测试这些因素是否共同或单独解释了新热带植物进化枝（Merianieae、Melatomataceae）的多样化动态。在估计祖先区域以及生态位和性状差异随时间的变化后，我们采用系统发育路径分析作为综合工具来测试这些因素对多样化率的个体直接和间接影响的十一个假设。我们发现最有力的证据支持了中新世中期安第斯山脉隆起的殖民化和快速非生物气候生态位演化的相互关联效应，以解释梅里亚科植物多样化率的激增。在安第斯山脉的栖息地内，后来花卉差异的增加允许利用更广泛的授粉生态位（即从蜜蜂传粉者转向脊椎动物授粉者），但并不影响多样化率。我们的方法包括植物性状和花卉性状的进化，这在一般的植物多样性评估中很少见，强调木本习性和较大花朵的进化先于安第斯山脉的殖民化，但可能对于山地环境中的快速辐射至关重要。 总体而言，与生态机会是进化辐射的关键要素这一观点相一致，我们的结果表明，快速的生态位演化和性状转变的结合对于中新世中期安第斯山脉新可用生态位空间的开发至关重要。此外，如果我们旨在量化这些过程对多样化的相对和相互关联的影响，我们的结果强调了将非生物和生物因素纳入同一分析框架的重要性。