In recent years, epigenetics, namely the set of inheritable modifications of genome expression and processes inherited by non-genetic means , has emerged as an essential discipline for the understanding of biological processes. The extraordinary advances in sequencing techniques now allow the joint analysis of genomes, epigenomes and transcriptomes in all their complexity. These technologies have become accessible to teams who do not currently use classical molecular biology, thus giving new impetus to research aimed at elucidating the interrelationships between gene-environment-phenotype in adaptation and evolution processes. The discovery of the epigenome, and the characterization of its dynamics, are profoundly disrupting our view of the mechanisms of heredity and adaptation. As elsewhere, epigenetics have benefited enormously from the availability of model organisms. We believe that the time has come to place not only all the knowledge obtained on these systems, often chosen for reasons of relative simplicity and experimental accessibility, in an ecologically realistic context, but also to transfer this knowledge to the world. more complex species communities and their interactions. Researchers in ecology and evolution share fundamental concepts and questions. The integration of epigenetics into these questions will allow important theoretical advances in these fields. However, it requires conceptual mastery of the mechanisms involved in epigenetic regulation and of the experimental techniques necessary for their analysis. It is also essential to enrich the theoretical notions of epigenetics and to compare them with field data. For these reasons, the objective of RTP 3E is to bring together the expertise existing in France in order to create strong interactions between teams working in the fields of ecology and evolution and in the field of epigenetics.