WEIRDSEX: the evolutionary causes and consequences of unexpected mating systems.

This project will explore the causes and consequences of unexpected sexual behaviour in insects, or “when good mating systems go bad”.

Mating systems describe how, where, when and how often animals come together to mate and raise offspring (Shuker & Simmons 2014). In recent years, there has been a renewed interest in mating systems, not least because of our new understanding of just how common female multiple mating (polyandry) is across animals. However, it has also become clear that unexpected and seemingly non-adaptive behavioural phenotypes that arise during reproductive encounters are more common than we thought. As such, traditional views of mating systems and sexual interactions are being challenged in a number of theoretical and empirical ways.

First, there is an increasing realisation that same-sex sexual behaviour is actually quite widespread, questioning our understanding of mate recognition and sexual function (including in insects: Bailey & Zuk 2009). Second, sexual interactions between individuals of different species, so-called reproductive interference, are likewise rather widespread (Shuker & Burdfield-Steel 2017). Third, it is now clear that mating failure – the failure of individuals, particularly females, to produce offspring – is a more common phenomenon than predicted by our assumptions of strong natural and sexual selection on primary sexual function. Mating failure can arise in a number of ways (Greenway et al. 2015), with failure to achieve successful insemination despite successful copulation perhaps being one of the more perplexing examples.

In this project, the PhD candidate will explore how phenotypes such as reproductive interference, mating failure and same-sex sexual behaviour evolve, and how they interact with more traditional and expected outcomes of mating competition. Initial work will build on our current work on Lygaeus seed-bugs but a variety of empirical and theoretical avenues for research are possible.

The project will provide a number of key training opportunities for the successful candidate: (1) training in experimental design and behavioural techniques, in both the field and the laboratory; (2) quantitative skills, from data management through to statistical analysis; (3) communication skills, in terms of presenting work to both academic and non-technical audiences through a variety of media. There will also be opportunities for the use of molecular techniques to explore patterns of paternity, to develop meta-analytical tests of mating systems theory, or to develop and test new theory, depending on the interests of the student.

For further details of the work in the Insect Behavioural Ecology lab, please visit our website: http://insects.st-andrews.ac.uk. You are strongly encouraged to make informal enquiries before applying, so please also email Dr David Shuker at: [Email Address Removed].