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）中所发挥的作用迄今仍未明确。以植物为食的特化类群，其分化速率快于杂食性与肉食性类群，但在较短的宏观进化尺度下，这一模式有时会出现反转。本研究以叶口蝠科蝙蝠（noctilionoid bats）为研究对象，评估了饮食演化对物种形成速率的影响，并控制了系统发育树结构、速率异质性以及宏观进化模式（macroevolutionary regimes）的干扰。我们提出假说：植食性类群间的生态位分化与物种形成速率呈正相关，且该关联在不同宏观进化模式间存在差异。研究发现，新植食性谱系的起源速率会随饮食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，但广食性植食者与以植食为主的杂食者，其物种形成速率快于特化植食者、杂食者及肉食者。广食性植食并非演化死胡同。本研究表明，分析生态性状与演化历程时，需纳入宏观进化模式以及支系内部与支系间的演化速率变异。我们的方法克服了其他方法普遍存在的高假阳性率问题，同时阐明了植食性与特化性在物种形成中的作用。