image: An acorn weevil beetle (Curculio sp.) stands on a sunflower (Helianthus sp.). view more
Credit: Image courtesy of Duane D. McKenna.
Genomic analysis of beetles reveals fresh insights into their evolutionary origins and rich diversity, according to a study. Beetles, which belong to the order Coleoptera, account for a substantial fraction of animal species diversity on Earth, but the reasons for their evolutionary success remain unclear. Using large-scale genome data, Duane McKenna and colleagues reconstructed the beetle family tree, estimated timing and rates of beetle evolutionary diversification, and examined beetle genes thought to underpin specialized herbivory. The analyses resolved previously contested facets of the family tree and indicated that beetles evolved in the Carboniferous Period, around 327 million years ago. Most present-day beetle groups likely originated before the end of the Cretaceous Period, around the time of evolutionary ascendance of rapidly diversifying flowering plants. Further, the authors report, the diversification of plant-feeding beetles, which account for most beetle species, occurred after beetles acquired genes for plant cell wall-digesting enzymes. Such genes appear to have been acquired via horizontal transfer from fungi and bacteria and likely facilitated herbivory, including leaf and seed mining and stem and wood boring abilities, enabling beetles to adapt to and parallel the growing diversity of flowering plants. According to the authors, beetles owe their staggering diversity to an array of factors, including low rates of lineage extinction, codiversification with flowering plants, and horizontal gene transfer from microbes.
Article # 19-09655: "The evolution and genomic basis of beetle diversity," by Duane McKenna et al.
MEDIA CONTACT: Duane McKenna, University of Memphis, Memphis, TN; tel: 617-285-2822; e-mail: dmckenna@memphis.edu
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Journal
Proceedings of the National Academy of Sciences