Data from: Eating down the food chain: generalism is not an evolutionary dead end for herbivores

The role of trophic specialisation in taxonomic diversification remains unclear. Plant specialists diversify faster than omnivores and animalivores, but at shorter macroevolutionary scales this pattern sometimes reverses. Here, we estimate the effect of diet diversification on speciation rates in noctilionoid bats, controlling for tree shape, rate heterogeneity and macroevolutionary regimes. We hypothesise that niche subdivision among herbivores positively relates to speciation rates, differing between macroevolutionary regimes. We found the rate at which new herbivorous lineages originate decreases as rates of diet evolution increase. Herbivores experience higher speciation rates, but generalist herbivores and predominantly herbivorous omnivores speciate faster than specialised herbivores, omnivores and animalivores. Generalised herbivory is not a dead end. We show that analysing ecological traits and diversification requires accounting for macroevolutionary regimes and within- and between-clade variation in evolutionary rates. Our approach overcomes the high false-positive rates of other methods and illuminates the roles of herbivory and specialisation in speciation.营养特化（trophic specialisation）在类群分化（taxonomic diversification）中的作用迄今尚未阐明。植食性特化类群的分化速率高于杂食性与动物食性类群，但在较短的宏观演化尺度（macroevolutionary scales）下，该模式有时会发生反转。本研究以叶口蝠总科蝙蝠（noctilionoid bats）为研究对象，估算食性分化对其物种形成速率的影响，并控制系统发育树拓扑结构、速率异质性（rate heterogeneity）与宏观演化体制（macroevolutionary regimes）等混杂变量。我们提出如下假说：植食性类群内部的生态位细分（niche subdivision）与物种形成速率呈正相关，且该关联在不同宏观演化体制间存在差异。研究结果显示，新植食性演化支（herbivorous lineages）的起源速率随食性演化速率的提升而降低。植食性类群整体的物种形成速率更高，但广食性植食动物、偏植食性的杂食动物的物种形成速率快于特化植食动物、一般杂食动物与动物食性类群。广义植食性并非演化死胡同（dead end）。本研究表明，解析生态性状与演化分化关系时，需同时考虑宏观演化体制，以及演化支（clade）内部与演化支间的演化速率变异。我们的方法克服了其他方法普遍存在的高假阳性率（false-positive rates）问题，清晰阐明了植食性与特化作用在物种形成过程中的具体角色。