Lecturer: Anne-Florence Bitbol - Swiss Federal Institute of Technology in Lausanne
Abstract:
 Microbial populations often have complex spatial structures, with homogeneous competition holding only at a local scale. Population structure can strongly impact evolution, in particular by affecting the fixation probability of mutants. I will first discuss a general model for describing structured populations on graphs. Then I will show that the specific structure of the gut, with hydrodynamic flow and resulting gradients of food and bacterial concentrations, can increase the fixation probability of neutral mutants, which can have consequences for the diversity of the microbiota.