On the Emerging Codes for Chemical Evolution

Life has been described as information flowing in molecular streams (Dawkins, 1996).Our growing understanding of the impact of horizontal gene transfer on evolutionary dynamics reinforces this fluid-like flow of molecular information (Joyce, 2002). The diversity of nucleic acid sequences, those known and yet to be characterized across Earth's varied environments, along with the vast repertoire of catalytic and structural proteins, presents as more of a dynamic molecular river than a tree of life. These informational biopolymers function as a mutualistic union so universal as to have been termed the Central Dogma (Crick, 1958). It is the distinct folding dynamics-the digital-like base pairing dominating nucleic acids, and the environmentally responsive and diverse range of analog-like interactions dictating protein folding (Goodwin et al., 2012)-that provides the basis for the mutualism. The intertwined functioning of these analog and digital forms of information (Goodwin et al., 2012) unified within diverse chemical networks is heralded as the Darwinian threshold of cellular life (Woese, 2002).