TOWARDS A TEMPORAL FRAMEWORK FOR INORDINATE FONDNESS: RECONSTRUCTING THE MACROEVOLUTIONARY HISTORY OF BEETLES (COLEOPTERA)

Most molecular phylogenetic studies of beetles (order Coleoptera) using 18S rDNA have recovered the suborders Adephaga and Polyphaga as sister groups, together sister to the suborders Myxophaga and Archostemata, with Archostemata alone or in combination with Myxophaga as the closest relative of all other beetles. Analyses of data from other genes have recovered alternative arrangements. Estimated subordinal divergence times based on analyses of DNA sequence data and fossil calibrations range from similar to 285-266 million years ago (Ma), with most extant families estimated to have originated in the Jurassic. However, timing and patterns of ecological and taxonomic diversification remain uncertain for most beetle groups primarily due to limited gene and nucleotide sampling, missing data, and a corresponding lack of well-supported resolution. Consequently, the nature and degree to which events in earth's history (e.g., the diversification and rise of angiosperms to ecological dominance) have influenced the success of Coleoptera remains unclear. Nevertheless, the phylogeny of beetles is being revealed via molecular studies with large taxon and gene samples, presenting renewed and novel opportunities for the study of beetle macroevolution.