Paleontological Journal

, Volume 44, Issue 7, pp 728-736

First online:

Which came first, the virus or the cell?

  • V. I. AgolAffiliated withChumakov Institute of Poliomyelitis and Viral Encephalitides, Russian Academy of Medical SciencesMoscow State University Email author 


The nature of viruses and the fundamental difference between their reproduction mechanism and cell division are discussed. The ways for storage and expression of genetic information in viruses are considerably more diverse than in cells. It is widely accepted nowadays that the “RNA world” appeared earlier than the “DNA world.” Hypotheses of the origin of viruses are discussed in conjunction with these theories (a hypothesis that cells with a RNA-genome appeared first, and were followed by viruses, and a hypothesis according to which RNA-containing viruses appeared first). It is suggested in both cases that the DNA-genomes first appeared in viruses, and that viruses played a definitive role in the origin of archaeans, eubacteria, and eukaryotes.