Instituto Superior Técnico, Portugal
Eco-evolutionary dynamics in co-colonization systems with multiple strains
The high number and diversity of microbial strains circulating in host populations has inspired extensive research on the mechanisms that maintain biodiversity. While much of this work focuses on strain-specific and cross-immunity interactions, another less explored mode of pairwise interaction is via altered susceptibilities to co-colonization in hosts already colonized by one strain. Diversity in such interaction coefficients enables strains to create dynamically their niches for growth and persistence, and ‘engineer’ their common environment. How such a network of interactions with others mediates collective coexistence remains puzzling analytically and computationally difficult to simulate. Furthermore, the gradients modulating stability-complexity regimes in such multi-player endemic systems remain poorly understood. In this talk I will present results from two recent studies where we analyze such an interacting system and the eco-evolutionary dynamics that emerge. Adopting slow-fast dynamic decomposition of the original model, we obtain a replicator equation, which enables to highlight the key coexistence principles and the critical shifts in community dynamics potentiated by mean-field contextual gradients.