I’ll have a read of the link later. But to my way of thinking, a valid code or cipher has ‘hidden’ meaning thus:
If C= p, A = X, T = h, then ‘cat’ would equal pXh if the substitutions relationships were changed on a daily basis, then ‘cat’ could equal ‘dog’. This way the original language carries information to a receiver, yet the language is still English (garbled English).
For DNA to qualify as code it would have to do the same, e.g. DNA string GAT = protein X, will ATG ever produce protein X, ? because if it were a code it should be able to.
I would like to keep the other thread running along the direction of semantics if possible, but this is still a very important issue.
Here's a link that describes the characteristics of the genetic code. There are a number on the web.
Control processes cannot be understood in detail, if the meaning of information is not completely clear. The exchange of information between individuals (or functional elements) is called communication. Communication is based on the transmission of information that consists of signs. Each sign stands for or speaks of something. An information can therefore be regarded as a sum of signs. Information as such can neither be captured physically nor energetically.
The assignment of an information to a certain physical state is called coding. Each sign carries a meaning and is thus part of a signal. The letters of an alphabet are signs.
Code: The information theory distinguishes between languages that have evolved during historical periods of time and codes that have been developed for special purposes. But in a strictly formal sense, a language is a code, too. Probably the most famous natural code (according to the information theory a language) is the genetic code. The genetic information that is stored in the DNA with a content of four nucleotide signs is used for the production of proteins with a content of 20 amino acids signs.
This is just a web page that I stumbled across.