Grant: Discovery Grants Program - Individual

Conflicts of interest, where two agents disagree about the best outcome from their interaction, are widespread in human society and the natural world. A key example of conflict occurs between males and females, who achieve fitness in different ways. Yet, each sex forms an inescapable part of the environment for the other, leading to strong selection on each sex to gain an advantage in sexual interactions. My long-term objective is to understand the reach of this sexual conflict in animal life. We now know that sexual conflict can profoundly impact on biological processes, including diversification, speciation and extinction. However, major outstanding questions remain, and, in many ways, we have only scratched the surface of understanding the potential influence of sexual conflict. Until recently, progress has been challenging because sexual conflict has been studied mainly in model organisms in laboratories, where ecological relevance can be unclear, or in ecological model organisms, which lack genomic resources. My research addresses this knowledge gap, using insect systems whose unique advantages make them ideal for resolving questions about sexual conflict in the genome, at the molecular level, and among individuals and populations. For objective 1, I will investigate the ecology of sexual conflict from two angles, using water striders, an important model system for sexual conflict. First, I will use experimental evolution in a controlled laboratory setting to manipulate ecological variables and track evolutionary change in male and female traits related to sexual conflict. Second, I will sample natural populations to test how ecological variation relates to spatial variation in sexual conflict traits and the dynamics of those traits through time. This work will answer longstanding questions about how the local environment influences how sexual arms races unfold. For objective 2, I aim to discover the genetic basis of natural variation in male and female traits that mediate sexual conflict in water striders. Identifying these genes will allow new discoveries about the causes and consequences of sexual arms races and their signature in the genome. For objective 3, I will evaluate the scope for sexual conflict over what mothers eat, using fruit flies as a model. I will test the potential for conflict by evaluating the impact of maternal diet on the reproductive success of mothers and their mates and offspring; test the potential for males to manipulate female diet choice via seminal proteins transferred during mating; and use metabolomics test for male influence on female nutritional state at the molecular level. This research will tell us about the hidden potential for sexual conflict over female diet choice and whether female diet choice is fully under female control. Because sexual conflict is a universal feature of life, these studies have strong potential to change how we think about adaptation, coevolution and biological diversity.