While most evolutionary studies of host-pathogen dynamics consider pathogen evolution alone or host-pathogen coevolution, there is evidence that hosts can evolve more rapidly than their pathogen during initial outbreaks after disease introduction, e.g. evolutionary rescue. In these cases, spatial, temporal and epidemiological factors could all affect the evolutionary dynamics of the host population. To study such systems, we considered the case of one pathogen introduced into a metapopulation of hosts with two genotypes: wild type and robust in which there is a tradeoff in disease-driven mortality and spatial mobility. We employed a classic Susceptible-Infected model and explored how differences in mortality and migration affect the representation of host genotypes and total host population persistence.
Results/Conclusions
We find that greater difference in disease-driven mortality between the two host types selects for the robust genotype, but there is a point after which disease-driven mortality is so high as to drive the disease prevalence below the reproductive threshold, which ultimately benefits the wild type. Migration benefits the wild type but does not influence the total host population much when disease is introduced into all patches. Migration selects for the robust type by facilitating the disease spreading when the disease is introduced into only one patch, which significantly decrease the total host population size. This study reveals that both epidemiology and metapopulation ecology can play critical roles in host evolution during the emergence of a novel infection and provide guidance for host conservation and disease control.