“…Since the standard genetic code does not seem to be fully optimized to minimize the 428 effects of mutations or translational errors because much better codes can be 429 found [B lażej et al, 2016, Novozhilov et al, 2007, Santos et al, 2011 Monteagudo, 2017], other factors must have taken part in shaping its structure as well. 431 The addition of subsequent amino acids into the standard code could have proceeded 432 according to their relationships in biosynthetic pathways as claims the co-evolution 433 theory [Di Giulio, 1997, Di Giulio and Medugno, 1999, Di Giulio, 2004 2008, Wong, 1975, Wong et al, 2016.…”