Through comparison among properties of nucleic acids, proteins, and oligo peptides, here I discuss RNA world and “first contact” between RNA and oligo peptide. From viewpoints of error rates in polymerization of those macromolecules, early systems were highly likely to have lower fidelity than present translation systems. Although such inaccurate synthesis may limit length of biopolymer, it also makes evolution easy by filling valleys in an activity landscape on a sequence space. Separation of information molecule and function molecule may contribute to fast evolution of genes by differentiation of fidelities in polymerization of those molecules.