Understanding the ecology and evolution of defence-pollination conflicts in plants

Understanding how species adapt to different environments requires consideration of how they respond to multiple agents of natural selection. For example, plants interact with a wide range of organisms, including herbivores, pollinators, microbes and other plants. In response to natural selection by herbivores, plants have evolved diverse ways of defending themselves, often using toxic and deterrent secondary metabolites; in response to selection by pollinators, plants have evolved an extraordinary diversity of flower shapes, colours, and scents. These two research fields have traditionally been considered separately, and this has limited progress in plant evolutionary biology. For example, herbivores are usually given credit for driving increases in the quantity and diversity of leaf secondary metabolites; however, it is becoming clear that many of these metabolites also occur in nectar and pollen, and could also be under natural selection by pollinating insects such as bees, flies and moths. This can create evolutionary conflicts: for example, recent work in our group has shown that scent compounds that are repellent to leaf-chewing herbivores can be costly to plants when emitted from flowers, where they also repel mutualist bee pollinators. How plants balance reproduction and defence is a question with important implications for both basic and applied research.

We are seeking an enthusiastic and motivated student with interests in the evolutionary biology and ecology of plants and insects. Depending on the student’s interests, the project could test (1) how herbivores and pollinators jointly drive the evolution of defence traits, using experimental field studies of natural selection, (2) how trade-offs between defence and floral trait expression influence successful pollination, using a combination of floral scent analysis and behavioural studies, and/or (3) how plant reproductive traits influence the health and fitness of herbivorous and pollinating insects. The project will focus on species in the Solanaceae (the nightshades, including wild tomatoes and potatoes), which are an exceptional study system with replicate independent transitions in reproductive strategies, and highly diverse suites of defensive metabolites. There is scope for taking either macroevolutionary or population-level approaches, working in both the field and lab and with plants, insect herbivores and pollinators. As an interdisciplinary project, the student will have the opportunity to gain a wide range of quantitative, analytical and field-based skills in behavioural ecology, chemical ecology, metabolomics, insect immunology, plant ecology, entomology and evolutionary genetics. Skill development and training will be tailored to the student’s needs and career plans.
The successful student will join two highly collaborative and interdisciplinary research groups at Sheffield studying a wide range of problems in ecology and evolutionary biology, using insects and plants as study systems (see http://stuartcampbell-evoeco.staff.shef.ac.uk). Some relevant publications are provided below. Interested students are welcome to direct informal inquiries to Dr Stuart Campbell ([Email Address Removed]).