Convergent evolution of specialized generalists: Implications for phylogenetic and functional diversity of carabid feeding groups. Issue 20 (11th October 2020)

• Record Type: Journal Article
• Authors: Baulechner, Dennis; Jauker, Frank; Neubauer, Thomas A.; Wolters, Volkmar
• Is Part Of: Ecology and evolution. Volume 10:Issue 20(2020)
• Page Start: 11100
• Page End: 11110
• Publication Date: 2020-10-11
• Subjects: ecological specialization -- evolutionary ecology -- functional groups -- functional morphology -- geometric morphometrics -- morphological adaptation; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.6746
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Closely related species are often assumed to be functionally similar. Phylogenetic information is thus widely used to infer functional diversity and assembly of communities. In contrast, evolutionary processes generating functional similarity of phylogenetically distinct taxa are rarely addressed in this context. To investigate the impact of convergent evolution on functional diversity (FD) and phylogenetic diversity (PD), we reconstructed the phylogenetic structure of carabid trophic groups. We then analyzed the mandible shapes using geometric morphometrics to link specialization in functional morphology with feeding specialization among herbivores, generalist carnivores, and specialized consumers of Collembola. Our results show that carabid feeding groups are paraphyletic. Herbivory evolved at least twice and specialization to Collembola predation at least three times. Species within feeding groups share a remarkably similar mandible morphology, which evolved convergently. While specialized mandibles of herbivores and collembolan specialists represent an adaptation to their main food source, the particular mandible morphologies do not necessarily reflect the degree of food specialization within feeding groups. Only a few species with a specialized herbivorous mandible may occasionally feed on animals, but the range of specific food resources in generalist carnivore species is large, despite an almost identical mandible shape. Thus, convergent evolution in specialized feeding groups reverses the relationship between PD and functional similarity compared with generalist carnivores. We conclude that phylogenetic relationship is a poor proxy of FD in carabids. Moreover, the inconsistencies between relatedness, morphological adaptation, and ecological function require caution in the characterization of functional groups. Rather than assuming general relationships between PD and FD, we suggest integrating the analysis of evolutionary processes into functional community analyses. Abstract : In this study, we demonstrate that in carabids feeding groups and their morphological adaptations to the main food resource evolved multiple times convergently. Therefore, in carabids there is no clear relationship between phylogenetic distance and functional similarity. We further show that morphological specialization does not explain ecological specialization and many species are specialized generalists.