Integrating phylogenomics, natural history collection holdings, innovative morphology and paleontological data - The phylogeny and evolution of adephagan beetles as a case study

• Applicants: Dr. Michael Balke; Professor Dr. Rolf Georg Beutel; Professor Bernhard Misof, Ph.D.; Professor Dr. Oliver Niehuis
• Subject Area: Systematics and Morphology (Zoology)
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 367847602

Molecular systematics has made a tremendous progress in the last decades. The investigation of the evolution of Hexapoda culminated with a recently published study based on 1,478 orthologous genes of more than 100 terminal taxa (1KITE). Similarly, morphological techniques have been greatly improved leading to a renaissance of the exploration of structural features and a discipline referred to as "Evolutionary Morphology". These advances combined with an intensified investigation of very rich fossil collections, especially in Chinese and Russian institutions, open new perspectives to reconstruct the evolution of megadiverse Hexapoda. Here we use beetles of the suborder Adephaga (45,000 spp.) as a model case. One of the intriguing aspects of their evolution is that they occur in very diverse habitats: terrestrial, hygropetric, and aquatic. The evolutionary pattern leading to the remarkable ecological versatility is still insufficiently understood. The terrestrial Carabidae are the largest family of Adephaga (ca. 38,000 spp.). However, eight of the ten families are aquatic or semiaquatic (hygropetric habitats), with an impressive diversity in their morphology and life styles, including remarkably different larval habits (e.g., feeding and breathing) and swimming adaptations (from lacking completely to extremely efficient). A large number of studies dealing with the morphology and taxonomy of different subgroups are available as well as morphology-based phylogenies. However, phylogenetic investigations based on molecular data are still unsatisfying, with conflicting results (also with morphology-based trees) and no convincing phylogeny covering all major lineages with a sufficient taxonomic sampling. Genomic analyses are missing and a formal evaluation of the evolutionary history based on a robust phylogenetic hypothesis and calibration with thoroughly investigated fossils is still wanting. The project proposed her aims to address the evolution of the group (with a main focus on the aquatic families) using an integrative approach, including taxonomically comprehensive sampling of genomic data, extensive morphological evidence using innovative techniques (e.g., x-ray microtomography), and a new evaluation of the rich fossil record. We will develop a target DNA enrichment workflow for Adephaga, which will economically complement transcriptome data, and help to link existing collections to the phylogenomic pipeline.The project goals are therefore: Use a robust, time calibrated phylogenetic inference for Adephaga to test hypotheses of their morphological and ecological transitions; provide the tools for routine incorporation of existing tissues in phylogenomic analyses and thus present an approach integrating molecular systematics, innovative morphology and extensive paleontological data.

• DFG Programme: Research Grants