The genetic code as a hypothetical product of primordial viral evolution

Abstract The genetic code is a universal script for life on Earth in which the information is stored in a complex nonbinary base-4 system composed in groups of three. It is generally accepted that during the prebiotic RNA World primordial RNA sequences likely recruited early amino acids using specific number of bases, possibly triplets. There are several hypothetical scenarios regarding how it happened. However, the evolutionary basis and the underlying rationale for codon-specific amino acid assignments are yet to be determined. Among the very first entities on Earth were selfish RNA replicons that lacked a genetic code and could only catalyze their own replication. Supposedly, these primitive selfish elements were essentially unstable naked RNAs that required protective shells to survive. By forming an early protective shell (or capsid) from prebiotic amino acids linked to specific bases, they would not only facilitate the development of a rudimentary genetic code but become precursors to capsid-encoding virus-like structures. This viewpoint suggests that the requirement for genetic material to be encapsidated in a protective protein shell initiated the development of the genetic code, resulting in the formation of the first primitive, virus-like entities preceding the cellular life. The proposed model complements existing hypotheses of the code origin rather than replacing them.