title: Life before RNA.
abstract: The hypothesis that life originated and evolved from linear informational molecules capable of facilitating their own catalytic replication is deeply entrenched. However, widespread acceptance of this paradigm seems oblivious to a lack of direct experimental support. Here, we outline the fundamental objections to the de novo appearance of linear, self-replicating polymers and examine an alternative hypothesis of template-directed coding of peptide catalysts by adsorbed purine bases. The bases (which encode biological information in modern nucleic acids) spontaneously self-organize into two-dimensional molecular solids adsorbed to the uncharged surfaces of crystalline minerals; their molecular arrangement is specified by hydrogen bonding rules between adjacent molecules and can possess the aperiodic complexity to encode putative protobiological information. The persistence of such information through self-reproduction, together with the capacity of adsorbed bases to exhibit enantiomorphism and effect amino acid discrimination, would seem to provide the necessary machinery for a primitive genetic coding mechanism.
authors.affiliation: Global Technologies (NZ) Ltd., Dunedin, New Zealand. stephen@glotec.co.nz
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Sowerby
authors.forename: George B
authors.initials: GB
authors.lastname: Petersen
mesh_terms: D018559:Exobiology; D000069497:Origin of Life; D012313:RNA
chemical_list: D012313:RNA