title: Evolution of RNA viruses.
abstract: These arguments lead to the suggestion that four independent evolutionary lines exist within the general group of RNA viruses. These are positive strand viruses, negative strand viruses, double stranded viruses, and retroviruses. Three of the viral systems may well have shared genes but the double-stranded RNA viruses appear to represent a very different evolutionary line.
mesh_terms: D005075:Biological Evolution; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005814:Genes, Viral; D012317:RNA Phages / Q000235:genetics; D012328:RNA Viruses / Q000235:genetics* / Q000502:physiology; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D012190:Retroviridae / Q000235:genetics; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000502:physiology; D014779:Virus Replication
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases