The actual space is a lot smaller than it looks. Many amino acids have multiple codons that encode for them. You can also exclude cases where you have repeating stop codons (which detatch the RNA from the ribosome).
There's lots of processes that favor certain patterns over others, only considering the biochemistry of the cell, not even the fitness of the animal.
> 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.
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
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.
I've spent hours watching Drew Berry/WEHI movies and that whole process just seems like straight up alien technology. Blows me away to think about the scale that it's operating at within my body as I type this.
I think that maybe (with perhaps a very small probability) it actually could be alien technology.