Molecular evolution: First enzymes, gases as substrates and genetic templates

A fundamental problem in biology is the self-assembly of the first cells ca pable of growth and division under anoxic conditions on the Earth. Evolutio n proceeded by self-assembling and self-replicating cells that reproduced t heir own genetic information and also changed their genetic code over time. Was it also possible that some of the first proteins were catalytic and us ed gases as substrates and also acted as genetic templates.' This paper exp lores the possibility that primitive protein enzymes used gases as their su bstrates, and reverse translation may have been a feature in the self-assem bly of the first cell(s).