Médecine / Sciences 2002 ; 18 : 1146-54
Philippe Lopez, Didier Casane, Hervé Philippe
Abstract: The aim of molecular phylogenetics is to reconstruct the genealogical relationships between nucleic or amino acid sequences. The phylogeny of the species bearing these sequences can be then inferred, but also the molecular evolution of the genomes can be analysed. For gene families, the relative importance of gene duplications and horizontal gene transfers can be examined. The reliability of the methods used to infer molecular phylogenies relies on the accuracy of our knowledge about the mechanisms of sequence evolution. Tremendous progresses have been done in this field of research in the last few years that helped us to get a better picture of the universal tree of life. The methods to analyse the selective constraints acting at the protein level have also been much improved. In particular, the detection of the sites in a protein which are under positive darwinian selection is getting more powerful. It is now possible to use the prediction about the critical residues associated to functional shift as a guide for further experimental approaches.