Genomes use the genetic code to write TWO separate languages
“One describes how proteins are made, and the other instructs the cell on how genes are controlled. One language is written on top of the other, which is why the second language remained hidden for so long.”
“The genetic code uses a 64-letter alphabet called codons. The UW team discovered that some codons, which they called duons, can have two meanings, one related to protein sequence, and one related to gene control.”
http://www.washington.edu/news/2013/12/12/scientists-discover-double-meaning-in-genetic-code/
‘The Hidden Codes That Shape Protein Evolution’ https://www.sciencemag.org/content/342/6164/1325.full.pdf
‘Exonic Transcription Factor Binding Directs Codon Choice and Affects Protein Evolution’ https://www.sciencemag.org/content/342/6164/1367.full.pdf