Does form predict function? Linking ecology and phenotype in ichneumonid wasps (Hymenoptera, Ichneumonidae)

• Applicant: Bernardo Santos
• Subject Area: Systematics and Morphology (Zoology)
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 530224000

Can comparative data be used to establish reliable links between form and function? Phenotypic traits reflect the ecological roles played by organisms but are also influenced by phylogenetic history as well as physical and biochemical constrains. The relative impact of each of these factors in shaping phenotypes is still unresolved: if ecological demands are the major component driving phenotypic evolution, the corollary is a certain degree of predictability in the relationship between form and function. This project will investigate the link between ecology and phenotype using ichneumonid parasitic wasps, one of the most diverse insect lineages, as a study system. This will be accomplished by building and integrating (1) a time-calibrated phylogeny based on data from whole-genome sequencing for thousands of ichneumonid species; (2) a detailed phenotypic dataset analyzed with geometric morphometrics. The multivariate rendering of phenotypic variation, combined with phylogenetic information – a phylomorphospace – is a powerful tool to investigate the overarching hypothesis that ecological traits have predictable phenotypic signatures. Specifically, we will use the phylogeny to reconstruct transitions in ecological traits and use phylogenetic comparative methods to test (1) whether phenotypic data can be used to predict ecological traits; (2) if shifts in ecological traits can influence diversification regimes. The results of the project will have important implications for our understanding of the relationship between phenotypic and ecological traits, one of the ultimate goals of evolutionary biology. The existence of a predictive form-to-function framework would indicate that phenotypes are malleable and respond in predictable ways to environmental pressure. Meanwhile, incomplete or weak correspondence between phenotype and ecology would highlight the importance of phenomena such as many-to-one mapping and phylogenetic inertia. The results will also shed light on the interplay between ecological niche, functional novelty and diversification. Elucidating the drivers of diversification in highly diverse taxa is a fundamental pursuit of evolutionary biology, and this project will enable comparative studies for a group of organisms that is still poorly understood. From a more practical perspective, our results will test whether we can use shape data to predict ecological traits. Comprehensively mapping specific regions of the morphospace to certain ecologies would allow us to derive predictions for species of parasitic wasps for which host data are still scarce. Finally, this project will represent a major contribution to the systematics of one of the most diverse groups of organisms on Earth, providing a sound foundation for future applied research.

• DFG Programme: Research Grants