Origin and Evolution of Metabolic Pathways

Abstract

Contemporary genomes are the result of 3.5-4 billions of years of evolution. Their history can be traced using the increasing number of available sequences and a panel of bioinformatic tools. As a result it is now possible to shed some light on the mechanisms involved in their evolution and responsible for the shaping of metabolic pathways. These analyses also enabled to shed some light on the mechanisms and forces that drove the evolution of the earliest genes and genomes. Whole-genome comparison demonstrates that a high proportion of the gene set of different prokaryotes results from ancient gene duplications. Thus, the duplication of DNA sequences appears to have played a very important role in the evolution of genes and genomes. It suggests that the earliest living organisms contained a small number of genes that gave rise to new genes by duplication followed by evolutionary divergence. In the 30s Haldane and Muller suggested that duplicated genes might acquire different mutations eventually arriving to code for products with different catalytic features.