Metabolic Constraints on the Evolution of Genetic Codes: Did Multiple Preaerobic' Ecosystem Transitions Entrain Richer Dialects via Serial Endosymbiosis?

A spontaneous symmetry lifting model based on Tlusty’s elegant topological deconstruction suggests that multiple punctuated ecosystem resilience regime changes in metabolic free energy that were broadly similar to the aerobic transition enabled a punctuated sequence of increasingly complex genetic codes and protein translators. In a manner similar to the Serial Endosymbiosis effecting the Eukaryotic transition, codes and translators coevolved until the ancestor of the present narrow spectrum of protein machineries became locked-in by evolutionary path dependence at a relatively modest level of fitness reflecting a modest embedding metabolic free energy ecology. The simplest coevolutionary model of code-translator interaction has high and low fidelity quasi-equilibria consistent with the ‘virus world’ hypothesis of Koonin et al (2006). A more detailed search for empirical evidence of a sequence of ‘preaerobic’ ecosystem shifts in metabolic free energy availability or efficiency of use might be surpris-