Dr Peter H. Thrall, a research scientist studying evolutionary ecology of host-microbe interactions at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia, presented a special seminar titled “Coevolutionary interactions in the Linus-Melampsora host-pathogen system” at FABI on June 7th. Dr Thrall visited South Africa for the first time as external examiner for the PhD of FABI student, Sarai Olivier-Espejel’s. Using the interaction between Linum marginale (Australian flax) and Melampsora lini (the causal agent of rust disease on flax and linseed) as a model, Dr. Thrall discussed among others, the environmental factors that drive host-pathogen interactions in natural systems.