Microbial community dynamics in-silico, in-vitro, and in-vivo

Thousands of microbial species coexist in the human gut or in a gram of soil, but what maintains community diversity is still unclear. Experiments show that tens of species can coexist under simple conditions, e.g., where a single carbon source is provided. The complexity of the structure of these communities reflects the hidden complexity of the network of inter-species interactions and of the chemical and physical environment, which are constantly altered by bacterial growth phases. In this talk, I will discuss how the statistical properties of environmental variability can give rise to regularities in community variation. By studying this connection, I will show how relatively simple models of stochastic population dynamics can capture patterns of variability in empirical and experimental communities. I will then discuss how current theoretical ecology frameworks fail to predict reproducible experimental patterns of diversity and composition.