If selection of basepairs came first (which is implied by RNA world hypothesis), then base 64 is the minimal encoding length for 21 amino acids + signalling. Th

If selection of basepairs came first (which is implied by RNA world hypothesis), then base 64 is the minimal encoding length for 21 amino acids + signalling. The question of why isn't it more complex becomes slightly moot - it's as simple as it can be given constraints. The question is why it isn't simpler then becomes asking why we have 21 amino acids.