Viral diseases and human evolution.

The interaction of man with viral agents was possibly a key factor shaping human evolution, culture and civilization from its outset. Evidence of the effect of disease, since the early stages of human speciation, through pre-historical times to the present suggest that the types of viruses associated with man changed in time. As human populations progressed technologically, they grew in numbers and density. As a consequence different viruses found suitable conditions to thrive and establish long-lasting associations with man. Although not all viral agents cause disease and some may in fact be considered beneficial, the present situation of overpopulation, poverty and ecological inbalance may have devastating effects on human progress. Recently emerged diseases causing massive pandemics (e.g., HIV-1 and HCV, dengue, etc.) are becoming formidable challenges, which may have a direct impact on the fate of our species.