Biological languages follow the laws of thermodynamics
By mixing soapy water, oil and the theory of information, a physicist has found a possible clue to the origin of the genetic code, as well as to the structure of other biochemical languages.
Life’s workhorse molecules are made from only 20 different types of amino acids, encoded in the chemical makeup of DNA. In principle, DNA could code for about three times that many, 64 possible combinations. Comparing the genetic code with the physics of soapy water suggests an explanation for why nature chose 20 as an optimal number, Tsvi Tlusty of the Weizmann Institute of Science in Rehovot, Israel, reports in an upcoming Proceedings of the National Academy of Sciences.
Genes are segments of DNA that encode instructions for constructing the molecules, primarily proteins, needed to build and operate cells. Each gene is a long sequence of “letters” — A, C, T and G — symbols for the chemical bases adenine, cytosine,