This paper examines the origins of
parasites, their relationship to their host and how they have evolved in tandem with many
other organisms. The paper seeks to answer several questions including why
parasites live where they do and how the origins of
evolution affect different parasites, specifically RNA and what role protozoans play in the life of parasites. The paper also discusses the process of Coevolution and the effect that a parasite's long-term residence has on the body of different species, including humans.