Form-function relationships in dragonfly mandibles under an evolutionary perspective

Blanke, Alexander; Schmitz, Helmut; Patera, Alessandra; Dutel, Hugo; Fagan, Michael J.

Abstract

© 2017 The Author(s). Functional requirements may constrain phenotypic diversification or foster it. For insect mouthparts, the quantification of the relationship between shape and function in an evolutionary framework remained largely unexplored. Here, the question of a functional influence on phenotypic diversification for dragonfly mandibles is assessed with a large-scale biomechanical analysis covering nearly all anisopteran families, using finite element analysis in combination with geometric morphometrics. A constraining effect of phylogeny could be found for shape, the mandibular mechanical advantage (MA), and certain mechanical joint parameters, while stresses and strains, the majority of joint parameters and size are influenced by shared ancestry. Furthermore, joint mechanics are correlated with neither strain nor mandibular MA and size effects have virtually play no role for shape or mechanical variation. The presence of mandibular strengthening ridges shows no phylogenetic signal except for one ridge peculiar to Libelluloidea, and ridge presence is also not correlated with each other. The results suggest that functional traits are more variable at this taxonomic level and that they are not influenced by shared ancestry. At the same time, the results contradict the widespread idea that mandibular morphology mainly reflects functional demands at least at this taxonomic level. The varying functional factors rather lead to the same mandibular performance as expressed by the MA, which suggests a many-to-one mapping of the investigated parameters onto the same narrow mandibular performance space.

Citation

Blanke, A., Schmitz, H., Patera, A., Dutel, H., & Fagan, M. J. (2017). Form-function relationships in dragonfly mandibles under an evolutionary perspective. Journal of the Royal Society interface / the Royal Society, 14(128), Article 20161038. https://doi.org/10.1098/rsif.2016.1038

• Journal Article Type: Article
• Acceptance Date: Mar 2, 2017
• Online Publication Date: Mar 22, 2017
• Publication Date: 2017-03
• Deposit Date: Apr 6, 2017
• Publicly Available Date: Mar 23, 2018
• Journal: Journal of the Royal Society interface
• Print ISSN: 1742-5689
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 128
• Article Number: 20161038
• DOI: https://doi.org/10.1098/rsif.2016.1038
• Keywords: Insect; Finite element analysis; Geometric morphometrics; Functional morphology; Phylogeny
• Public URL: https://hull-repository.worktribe.com/output/450398
• Publisher URL: http://rsif.royalsocietypublishing.org/content/14/128/20161038
• Additional Information: This is the accepted manuscript of an article published in Journal of the Royal Society interface, 2017. The version of record is available at the DOI link in this record.
• Contract Date: Mar 23, 2018