The evolution of aminoacyl-tRNA synthetases, the biosynthetic pathways of amino acids and the genetic code.

In this paper the partition metric is used to compare binary trees deriving from (i) the study of the evolutionary relationships between aminoacyl-tRNA synthetases, (ii) the physicochemical properties of amino acids and (iii) the biosynthetic relationships between amino acids. If the tree defining the evolutionary relationships between aminoacyl-tRNA synthetases is assumed to be a manifestation of the mechanism that originated the organization of the genetic code, then the results appear to indicate the following: the hypothesis that regards the genetic code as a map of the biosynthetic relationships between amino acids seems to explain the organization of the genetic code, at least as plausibly as the hypotheses that consider the physicochemical properties of amino acids as the main adaptive theme that lead to the structuring of the code.