Coevolved nestedness and modularity in phage-bacteria infection networks

Phage and their bacterial hosts form the most diverse and abundant biological communities on Earth. Interactions between strains (i.e. who infects whom) can be represented using Phage-Bacteria Infection Networks (PBINs)(Weitz et al., 2013). Observed PBINs have been analysed using the matrix metrics of nestedness and modularity (Flores et al.,2011). At small phylogenetic scales, PBINs often show high nestedness; at larger scales, PBINs show high modularity. We are using coevolutionary simulations to understand how these structural features of observed PBINs might arise from coevolutionary dynamics.