Abstract. This paper presents a model of the co-evolution of transmissible disease and a population of non-randomly mixed susceptible agents. The presence of the disease elements is shown to prevent the onset of genetic convergence of the agent population. The epidemiological model also acts in a distributed fashion to counter the tendency of the agent population to occupy spatially closeknit communities. The simulation applies a modified mathematical SIR epidemiological model of disease transmission in combination with the wellstudied technique of artificial ecosystems. It includes various aspects of disease transmission that are not usually modelled due to the effort required to incorporate them into mathematical models. These include a distributed agent population with non-uniform infectiousness and immunity as well as a mutable disease model with evolving latency and infections that evolve to prey on diverse agent characteristics. Keywords. epidemiological model, co-evolution, arti...