In short Looking at the genetic code, it appears that most redundancy is on the third letter rather than on the first or the second letter of the codon. Why has it evolved this way? Longer version ...
There is some literature which shows that all start codons code for methionine. However, in the standard genetic code, the alternative start codons clearly code for leucine. Does that mean these ...
We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?