Molecular phylogenetics of A ustralian weevils ( C oleoptera: C urculionoidea): exploring relationships in a hyperdiverse lineage through comparison of independent analyses

With over 60 000 described species in approximately 5800 genera, weevils ( C urculionoidea) represent one of the most diverse and species‐rich superfamilies of eukaryotes on the planet. Recent attempts to resolve the phylogeny of family‐group taxa in weevils using morphological, molecular or combined data sets have produced vastly different patterns of relationships, particularly within the largest family, C urculionidae. Here we present an estimation of the phylogeny of A ustralian weevils and of the divergence dates of the major lineages based on a multi‐gene data set (28S, 16S and COI ) spanning ∼3.5 kbp of DNA sequence. We assess its topological similarities to, and differences from, other recently published phylogenetic trees, particularly in relation to taxon sampling and relative diversity of the lineages, and we discuss the implications for weevil systematics. Our results, derived from a different set of taxa that has different combination of loci and different fossil calibration points, recover a number of relationships and age estimates that are congruent with those obtained by other recent weevil phylogeny estimates, indicating that we are beginning to recognise the major monophyletic lineages and reconstruct the major diversification events within C urculionoidea. Resolution of natural groups within families (e.g. subfamilies and tribes) however remains poor, even for studies with the largest volume of sequence data (whole mitochondrial genome analyses), evidently largely due to deficient taxon sampling. Although taxon sampling is known to be one of the most critical determinants of accurate phylogenetic reconstruction, it is rarely addressed in phylogenetic assessments. Our case study of weevils highlights not only its importance, but also the fact that it is very difficult to achieve comprehensive representative sampling in hyperdiverse lineages because of their sheer taxic diversity. Doubts concerning the monophyly of many subordinate lineages exacerbate this problem, restricting the use of exemplar approaches to taxon sampling. The value of comparing different data sets and analyses for assessing systematic relationships is often overlooked, even despite the presence of many conflicting results in previous phylogenetic hypotheses. A summary of relationships recovered relative to taxon sampling and methodological differences between different phylogenetic reconstructions provides an important stepping‐stone in understanding the diversification of weevils.