[alphazard]

> Many amino acids have multiple codons that encode for them.

I didn't know this. I suspect this evolved because some amino acids are more useful than others, and increasing the probability of encoding for them was beneficial.

[robbiep]

Have a read (rather than guessing) - it’s fascinating! Your other reply has a good insight but on more of a related topic but the primary reason this exists is for error correction. So approx one third of single nucleotide mutations have no change on the expression of the DNA or protein. And some of those that do change the amino acid are actually conservative; ie changing a basic amino acid to another basic amino acid which may still end up folding in the same way

[thaumasiotes]

There was a paper a while ago documenting that "synonymous" codons took different amounts of time during assembly, causing differences in the folded structure of the protein.