Emergence of Function and Selection from Recursively Programmed Polymerisation Reactions in Mineral Environments

<b>Living systems are characterised by an ability to sustain chemical reaction networks far-from-equilibrium. It is likely that life first arose through a process of continual disruption of equilibrium states in recursive reaction networks, driven by periodic environmental changes allowing the emergence of a memory. Herein, we report the emergence of proto-enzymatic function from recursive polymerisation reactions using amino acids and glycolic acid over four wet-dry cycles. Reactions are kept out of equilibrium by diluting products 9:1 in fresh starting solution at the end of each recursive cycle, and the development of complex high molecular weight species is explored using a new metric, the Mass Index, which allows the complexity of the system to be explored as a function of cycle. This process is carried out on a range of different mineral environments. We explore the hypothesis that disrupting equilibrium <i>via</i> recursive cycling imposes a selection pressure and subsequent boundary conditions on products, which may otherwise be prone to uncontrolled combinatorial explosion. After just four reaction cycles, product mixtures from recursive reactions exhibit greater catalytic activity and truncation of product space towards higher molecular weight species compared to non-recursive controls. </b>