Thesis: Can increased relatedness and between-group selection mediate female harm in the seed beetle Callosobruchus maculatus?
For my PhD, I will examine the roles of inclusive fitness and multilevel selection in mediating sexual conflict and female harm during reproduction. In many species, a male will harm a female during reproduction, enhancing his own paternity share but potentially reducing the future productivity of the female. This could represent an indirect fitness cost to the male if the female is likely to remate with his relatives in the future.
By using the seed beetle Callosobruchus maculatus as a model species and manipulating the kin structure of breeding groups, I aim to determine the role of relatedness in both the short term adjustment of female harm by individual males and population-level changes in female harm over generations. I will also examine the importance of between-group selection in allowing kin selection to operate, and the role of olfactory cues in kin recognition.
Why my research is important
Sexual conflict, which occurs when potential partners maximise their fitness through mutually exclusive means, has been studied almost exclusively in terms of the direct fitness consequences to the individuals involved. The indirect fitness effects (or the consequences for the genetic relatives of the individuals involved) of these interactions have been largely ignored. In structured populations in which neighbours are likely to be related, however, indirect effects can have important consequences for the evolution of behavioural traits. These effects could potentially help explain the diversity in sexual conflict and female harm seen across species.
Although recent studies have made important progress in this direction, it remains an under-explored area. In particular, my project will be the first to use an experimental evolution approach to examine the effect of kin structure on female harm. The seed beetle life cycle also means that the effects of social familiarity and relatedness per se can be disentangled.
The balance between conflict and cooperation is important for the short-term persistence and long-term evolution of populations. The study of both the direct and indirect consequences of interactions such as sexual conflict is therefore important for understanding the processes by which diversity is produced and maintained.
It's also fascinating.