Simulation Procedure

All simulations were carried out in Julia version 1.3.0 \cite{Bezanson_2017}, with graphics produced using the ggplot2 package \cite{nokey_854cc} in R version 3.6.1 \cite{nokey_c6dbe}. For simplicity of presentation, we fix the values of all variables other than β (the infection rate) and Δ (the network of movement information) to be identical for all populations in the metapopulation. To demonstrate the variety of dynamics obtainable in this modeling framework, we vary \[\tilde{R_0} = \frac{\beta}{\sigma + \mu + E_{kk}},\]where Ekk = -Δkk, as noted above, signifies the total outgoing movement from the population of interest. We add a ~ over R0 to denote that this is an approximation of the true reproductive number, the precise form of which would additionally take into account the inflow of infectious individuals from other populations. We additionally vary Δ according to the number and interconnectedness of the populations. For the figures of the main text, we utilize a strain structure of two loci, each with two alleles. Sensitivity to these parameter choices is explored in the supporting information (Fig \ref{124825}).