Coevolution is the evolution in two or more species in which the evolutionary changes of each species influence the evolution of the other species. In other words, each species exerts selection pressures on, and evolves in response to, the other species. ... Naomi Pierce gives an account of coevolution.
Evolution is the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth. Coevolution is the influence of closely associated species on each other in their evolution.
Metastasis is the process in which cancer cells break away from the place where they first formed and travel through the bloodstream to other parts of the body where they form a new tumor.