On Code-Prompting Auto-Catalytic Sets and the Origins of Coded Life

Abstract

The genetic code and genetic evolution are at the core of complexity in biology, however, there is no reasonable explanation yet for the emergence of the genetic code. We present here a possible scenario accounting for the emergence of “coded life” in nature: We describe the emergence of the genetic code from molecular evolution (prior to genetic evolution). This process is based on increase in concentration of chemical self-replicating sets of molecules, located within (probably non-biological) compartments. Our scenario is obtained by combining the conceptual idea of “code-prompting autocatalytic sets” (Agmon and Mor, 2015), with recent results about non-enzymatic template replication methods (Prywes et al, 2016), possibly relevant to the prebiotic stage preceding RNA-world. In the scenario described here, we often use computer science viewpoint and abstraction: We consider sets of strings composed of letters, such that each letter represents a molecular building block — mainly nucleotides and amino acids, and each string represents a more complex molecule which is some concatenation of the simpler molecules represented by letters; the biochemical rules are described in an abstract language of rules and statistics of letters and strings. We then suggest a novel path, containing several phases, for the emergence of “coded life”.