The difference in evolutionary interests of males and females can select for traits that favour an individual??s fitness at the expense of their mate??s lifetime fitness. Despite the widespread occurrence of this sexual conflict over reproductive interactions, however, research to date has largely focused on the fitness costs imposed on females by manipulative males. Empirical evidence is particularly sparse for how mating can also be costly for males, the genetic structure of traits involved in reproductive interactions, and how sexual conflict can modify sexual selection in general. My aim was to explore the broader evolutionary consequence of sexual conflict and male-female interactions. In the nuptial-feeding Australian ground cricket, Pteronemobius sp., I used an experimental evolution approach to explore how diet and sexual conflict interact to determine the costs of mating. In the Australian black field cricket, Teleogryllus commodus, I used molecular and quantitative genetic approaches to characterise the fitness consequences and genetic basis of spermatophore attachment, a trait at the centre of inter-locus sexual conflict, and then related this to both condition and male attractiveness. Finally, in T. commodus, I quantified how sexual conflict alters the sexual selection acting on male sexual traits and how this in turn shapes genetic architecture and the persistence of additive genetic variance. My results demonstrate the complex nature of reproductive interactions between males and females. Importantly, I show that diet can mediate the expression of sexual conflict in a mating system and shape the evolution of male life-span. I also show that reproductive interactions influence the fitness benefits that both male and females obtain from mating in ways that are not predicted by current theory and that much of the potential for such traits to co-evolve is via a common genetic association with condition. Finally, I demonstrate that sexual conflict can profoundly modify the process and outcome of sexual selection, thereby influencing how additive genetic variation is maintained in a suite of male sexual traits. These results highlight the need for a greater integration of sexual conflict and sexual selection theory as the evolutionary potential and significance of sexual conflict may currently be underestimated.
| Identifer | oai:union.ndltd.org:ADTP/225449 |
| Date | January 2008 |
| Creators | Hall, Matthew, Faculty of Science, UNSW |
| Publisher | Publisher:University of New South Wales. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://unsworks.unsw.edu.au/copyright, http://unsworks.unsw.edu.au/copyright |
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