Can higher-level phylogenies of weevils explain their evolutionary success? A critical review.

We review a series of related publications that combine higher-level phylogenies of weevils (Coleoptera: Curculionoidea) with host plant information to explain the success of this megadiverse lineage in the context of a coevolutionary escape-and-radiation hypothesis. We argue that the authors' approach, though by no means isolated, is marred by the cumulative effect of (1) inadequate taxon sampling, particularly within the most diverse family Curculionidae; (2) insufficient reconciliation of systematic evidence, including the reassessment of morphological characters and necessary classificatory emendations; (3) exceedingly wide concepts of ecological similarity, leading to uninformative tests of adaptation; (4) insufficient resolution of the temporal sequence of associated weevil and angiosperm radiations; and (5) inadequate consideration of alternatives to the escape-and-radiation hypothesis. As a result, there are very few new and reliable inferences about the evolutionary success of weevils that depend precisely on the phylogenetic data presented in these studies. Improved taxon sampling alone is not the solution, because the existing mid-level classification of weevils is too deficient to permit inferences about natural lineages and their ancestral traits. We therefore recommend abandoning such a higherlevel approach in favor of more narrowly focused reconstructions of the evolutionary history of generic and tribal groupings.