The Origin and Evolution of Viruses

1 Theories on the Origin of Viruses 2 Virus Evolution and Mechanisms Involved 3 Biological Significance of Virus Quasi Species 4 Effect of Mutations on Viral Phenotypes 5 Virus Evolution and New Antiviral Strategies Keywords: origin and evolution of viruses; primitive replicons; DNA viruses; viroids and circular satellite RNAs; riboviruses; retroviruses; Epstein–Barr virus (EBV); negative-strand riboviruses