Autocatalysis in Chemical Networks: Unifications and Extensions

Autocatalysis is an essential property for theories of abiogenesis and chemical evolution. However, the different formalisms proposed so far seemingly address different forms of autocatalysis and it remains unclear whether all of them have been captured. Furthermore, the lack of unified framework thus far prevents a systematic study of autocatalysis. Here, we derive general stoichiometric conditions for catalysis and autocatalysis in chemical reaction networks from basic principles in chemistry. This allows for a classification of minimal autocatalytic motifs, which includes all known autocatalytic systems and motifs that had not been reported previously. We further examine conditions for kinetic viability of such networks, which depends on the autocatalytic motifs they contain. Finally, we show how this framework extends the range of conceivable autocatalytic systems, by applying our stoichiometric and kinetic analysis to autocatalysis emerging from coupled compartments. The unified approach to autocatalysis presented in this work lays a foundation towards the building of a systems-level theory of chemical evolution.