Phenotypic variation in spatially structured microbial communities: ecological origins and consequences

Microbial cells in nature live within dense multispecies conglomerates, forming a self-organizing ecosystem. In such assemblies, genotypes interact with each other in a myriad of ways, driving community dynamics and functionalities. The role of interactions between genotypes and their consequences for spatial structure and functional outcomes are being increasingly studied to understand the ecology and evolution of microbial communities. An increasing body of work with simple microbial populations has elucidated that phenotypic variation, that is, differences within isogenic cells can have important consequences for population dynamics and evolution. However, the role of individual level behavioral differences for community level dynamics is relatively unknown. I argue that it is necessary to study phenotypic variation and microscale processes in order to understand the emergence and consequences of interactions within microbial communities. I highlight possible explanations that can explain the emergence of variation in multi-genotypic assemblages and propose possible consequences on community dynamics.