Origin of viruses: primordial replicators recruiting capsids from hosts

  title={Origin of viruses: primordial replicators recruiting capsids from hosts},
  author={Mart Krupovic and Valerian V. Dolja and Eugene V. Koonin},
  journal={Nature Reviews Microbiology},
Viruses are ubiquitous parasites of cellular life and the most abundant biological entities on Earth. It is widely accepted that viruses are polyphyletic, but a consensus scenario for their ultimate origin is still lacking. Traditionally, three scenarios for the origin of viruses have been considered: descent from primordial, precellular genetic elements, reductive evolution from cellular ancestors and escape of genes from cellular hosts, achieving partial replicative autonomy and becoming… 
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