His research focuses on the evolutionary analysis of genomes and biological networks. Within this framework, Olivier Lespinet is involved in the development of several projects, the most significant of which are the evolution of synteny in prokaryotes, the discovery and identification of orphan enzymatic activities, and the annotation and analysis of the genome of the filamentous fungus Podospora anserina, the study of the diversity, dynamics and evolution of biological networks and the study of biological networks (genetic regulation networks, protein interaction networks, metabolic networks) is a good way of understanding how living organisms evolve and function. In addition to purely experimental approaches aimed, for example, at listing the proteins interacting with each other under a given physiological condition for a particular organism, in silico approaches based on these experimental data, coupled with comparative genomics approaches, are now also making it possible to study biological networks.