OTHER PLAYERS. “Phylogenetic analysis of translation system components, in particular aminoacyl–tRNA synthetases, shows that, at a stage of evolution when the translation system had already attained high fidelity, the correspondence between amino acids and cognate codons was determined by recognition of amino acids by RNA molecules, i.e., proto-tRNAs.”
http://www.annualreviews.org/doi/abs/10.1146/annurev-genet-120116-024713