Experimental evolution studies demonstrate that pathogens evolve
rapidly, have a large capacity for increased virulence and
cause disease in many different ways. A large proportion of
genetic diversity for host susceptibility to infectious,
autoimmune and 'genetic' diseases, and to cancer, is probably
caused by pathogens and/or host counteradaptations. Recent
advances in diverse fields support this claim and suggest many
underused approaches for identifying and experimentally
dissecting the complicated hostpathogen interactions that
often lead to disease.