The genetic code is universal, which means that the same code is found in all living things, providing evidence of common evolutionary origins of all organisms. The genetic code is unambiguous. This means that each codon codes for just one amino acid (or for start or stop). As a result, there is no mistaking which amino acid is encoded by a given codon. The genetic code is also redundant. This means that each amino acid is encoded by more than one codon. This helps prevent errors in protein synthesis because an accidental change in a single base often has no effect on which amino acid the codon encodes.