The evolution processes of DNA sequences, languages and carols

The sequences of bases A, T, C and G of about 100 enolase, secA and cytochrome DNA were analyzed for attractive or repulsive interactions by the numbers T1,T2,T3;r of nearest, next-nearest and third neighbor bases of the same kind and the concentration r=other bases/analyzed base. The area of possible T1,T2 values is limited by the linear borders T2=2T1−2,T2=0 or T1=0 for clustering, attractive or repulsive interactions and the border T2=−2T1+2(2−r) for a variation from repulsive to attractive interactions at r⩽2. Clustering is preferred by most bases in sequences of enolases and secA’s. Major deviations with repulsive interactions of some bases are observed for archaea bacteria in secA and for highly developed animals and the human species in enolase sequences. The borders of the structure map for enthalpy stabilized structures with maximum interactions are approached in few cases. Most letters of the natural languages and some music notes are at the borders of the structure map.