I am looking for a PhD student to join my research group ‘Stochastic Evolutionary Dynamics’ at the Max Planck Institute for Evolutionary Biology in Plön, Germany. In my group, we develop theoretical models to to answer questions in evolutionary biology at the intersection to ecology and medicine. The PhD project is about modeling parasite epidemics in host populations with symbiont-mediated immunity.

Protective symbionts can provide hosts with immunity against virulent parasites. Yet, symbionts themselves may also be costly for the host. The form of symbiosis is thus context dependent: mutualistic upon exposure (or infection) with the virulent parasite but parasitic in its absence. The probability of exposure to the virulent parasite and thus the expected form of symbiosis changes over the course of a parasite epidemic. In turn, the prevalence of symbionts in the host population affects the parasite dynamics, creating complex feedbacks between the densities of hosts, parasites, and symbionts. In this project, we will develop theoretical models to study the joint changes in the densities of hosts, symbionts, and parasites and the associated changes in the form of symbiosis.

The position is part of the DFG-funded Collaborative Research Unit ‘Density dependent symbiosis in planktonic systems – DynaSym’, which brings together several research groups across Germany to test and develop basic concepts of density dependence of the symbiosis form (e.g., shift from predator-prey to mutualistic interaction and back).