Parastitism?

Parsitsm is a form of symbiosis which refers to the relationship between the parastite and its host. Parastism can assume many forms from endoparasitism to ectoparasitism and epiparasitism. The resultant effect of parasitism can be that the host does benefits, become harmed or experience a neutral relationship. But is there a possibility that parasitism is a form of mechanism present in the environment that drives the process of evolution? For example, the host may evolute to develop resistance to the parasite that has been closely associated with its predessors or the host may undergo a shift in its behavioural pattern and change its target benefactor?

Yes good thinking. Look up the Red Queen Hypothesis. For example, it is possible that part of the evolutionary advantage of sexual reproduction is that it enables rapid resistance to parasites (which evolve quickly due to their short life-cycles).

Are you calling all tax payers parasites? Go to hell Commie...

Ah... Radio Edit....

" Is "Mutualism" in a "HOST/ PARASITE" relationship what you are looking for ?

Humans did not evolve mutiple blood groups and tissue types to prevent transfusion and transplantation. Our cell surfaces are varied so that no one surface molecule can be exploited by a virus and the entire population wiped out.