Genetic code evolution as an initial driving force for molecular evolution

There is an intrinsic relationship between the molecular evolution in primordial period and genomic or proteomic properties of contemporary species. The genomic data may help us understand the driving force of evolution of life at a molecular level. In the absence of evidence, numerous problems in molecular evolution had to fall into a twilight zone of speculation and controversy in the past. Here we show that delicate variation patterns of genomic base compositions and amino acid frequencies resulted from the genetic code evolution, which underlies the molecular evolution. The theoretical results agree with the experimental observations very well, not only in the evolutionary trends of amino acid frequencies and genomic base compositions but also in many detailed characters. Inversely, the genomic data of contemporary species can help us unravel the genetic code chronology and amino acid chronology. Our results may shed light on the intrinsic mechanism of molecular evolution and the genetic code evolution. (C) 2009 Elsevier B.V. All rights reserved.