To decipher the genomes of living organisms, it is necessary to take into account the fact that they are the result of billions of years of evolution. Their sequences are the consequence of evolutionary processes (mutation, natural selection, genetic drift, ...) that are acting or had been acting in the past. The comparison of homologous sequences (from different species or within a genome) is therefore an essential approach, first to reconstruct the evolutionary history of species and of the genes they harbor in their genomes, and secondly to study the functional and structural constraints that shape genomes.

The Helix research group is working on both topics:

 determining the evolutionary history of homologous sequences (molecular phylogeny)

 studying the evolutionary processes acting on genomic sequences (comparative genomics), see "Spatial organization of genomic information".

The group is involved in the development of bioinformatic tools for molecular phylogeny and for large scale comparative sequence analyses:

 databases of homologous gene families
 algorithms and software for molecular phylogeny