Fitness effects of evolutionary manipulations of adult sex ratio and diet in fruit flies

McConnell, Nathan John (2023) Fitness effects of evolutionary manipulations of adult sex ratio and diet in fruit flies. Doctoral thesis, University of East Anglia.

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The thesis research provides insight into the evolutionary changes in response to long-term manipulation of adult sex ratio and adult diet in the fruit fly Drosophila melanogaster. I first synthesised understanding of how long-term manipulations of adult sex ratios have been used to test key hypotheses in responses to selection and used this to identify gaps in knowledge (Chapter 1). I then contributed to our understanding of the evolution of plasticity in female behaviour in response to the pre-copulatory social environment. The results showed that these female plasticity traits were relatively stable despite exposure to divergent levels of sexual selection and adult nutritional environment (Chapter 2). The effect of the strength of sexual selection on morphological phenotypes is not well understood and few experiments have incorporated study of the additional effects of condition dependency. In chapter 3 I provide evidence that variation in the strength of sexual selection resulted in evolved responses in important physiological traits such as wing size, body weight, and female developmental rate and that these responses were condition dependent. In chapter 4 I showed that the strength of sexual selection and dietary restriction can drive changes in reproductive morphology, for the first time demonstrating evolved responses in female spermathecal size. Finally, I contributed to the understanding of how the strength of sexual selection can act on the expression of a key seminal fluid protein ‘Sex peptide’. The thesis integrates a diverse range of techniques to explore how sexual selection enacts on individuals to drive phenotypic change in a population, promoting the experimental use of experimental evolution of long-term modification of adult sex ratio and diet.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Nicola Veasy
Date Deposited: 08 Jul 2024 13:31
Last Modified: 08 Jul 2024 13:31


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