Beetling about: using experimental evolution to understand dispersal behaviour in the pest/model insect Tribolium castaneum

Pointer, Michael D. (2025) Beetling about: using experimental evolution to understand dispersal behaviour in the pest/model insect Tribolium castaneum. Doctoral thesis, University of East Anglia.

Preview

PDF Download (29MB) | Preview

Abstract

Dispersal impacts gene flow and thus a web of eco-evolutionary processes that govern the fate of biological entities, from individuals to meta-communities. Consequently, it is crucial to understand how dispersal evolves. This thesis investigates dispersal in the crop pest and model insect, Tribolium castaneum, the red flour beetle. Despite its contribution to many important advances across over 100 years of experimental biology, no single source had collated this information. Therefore, in chapter two I review the extensive use of Tribolium beetles as a model in evolution and ecology. In chapter three I use divergent artificial selection to develop beetle lines showing repeatable dispersal phenotypes, demonstrating that the trait has a strong genetic basis, and supporting existing theory that this genetic basis may be relatively simple. Chapter four investigates the mechanistic basis of differences in dispersal. Results showed that dispersive phenotypes differ in their walking distance, straightness of travel and use of the substrate surface in ways that plausibly enhance dispersal. Chapter five investigates associations between dispersal and life-history traits, showing that dispersal is significantly associated with male mating behaviour, female reproductive investment, development time and female lifespan. These traits potentially characterise a dispersal syndrome in T. castaneum that shapes and constrains how the trait evolves in natural populations. In chapter six I return to the question of genetic architecture, employing genome resequencing of the selection lines to identify genomic variants associated with the dispersal phenotype. I find evidence supporting association with many candidate loci, amongst these are many known metabolic and neurophysiology genes, suggesting this may be the functional basis of dispersal variation. Finally, I synthesise the findings from each chapter and discuss what my results suggest about the evolution of dispersal in Tribolium, the wider relevance to our understanding of complex trait evolution and some possibilities for future research.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	Chris White
Date Deposited:	19 May 2025 14:16
Last Modified:	19 May 2025 14:16
URI:	https://ueaeprints.uea.ac.uk/id/eprint/99299
DOI:

Downloads

Actions (login required)

View Item