Abstract
For creatures in the natural world, parasitism is one kind of relationship with other species of creatures. The subject of this paper is the pathogen, a kind of parasite. Pathogens evolve to one with adaptive virulence and thus survive and multiply. We also discuss the effect of how they are transmitted on their evolution.We propose an evolutionary model of the pathogen that takes vertical transmission into consideration. We constructed a spatially-structured population by cellular automata, carried out simulations, and investigated how vertical transmission affects the evolution of the pathogen. Furthermore, we discovered the direction of the evolution changes with the parameters.
