Peptide‐dominated membranes preceding the genetic takeover by RNA: latest thinking on a classic controversy

It is commonly presumed that abiotic membranes were colonized by proteins later on. Yet, hydrophobic peptides could have formed primordial protein‐dominated membranes on their own. In a metabolism‐first context, “autocatalytically closed” sets of statistical peptides could organize a self‐maintaining protometabolism, assisted by an unfolding set of ribotide‐related cofactors. Pairwise complementary ribotide cofactors may have formed docking guides for stochastic peptide formation, before replicating RNA emerged from this subset. Tidally recurring wet‐drying cycles and an early onset of photosynthetic activities are considered most likely to meet the thermodynamic requirements. Conceivably, the earliest peptide‐dominated vesicles were engaged in light harvesting, together with isoprenoid‐tethered pigments, rather than providing an external boundary. Early on, the bulk of prebiotic organic matter can have formed a contiguous layer covering the mineral sediment, held in place by colloidal coherence of a hydrogel matrix. This unconventional scenario assumes a late onset of cellular individualization – perhaps from within, resembling endosporogenesis.