From an organizational perspective, organisms have the capacity to regulate and modify both their developmental processes and their interactions with the environment, while at the same time, they are able to incorporate influences of the environment in their developmental and self-maintaining dynamics. They achieve this by exhibiting a developmental organization that fosters the endogenous construction of complex patterns of its own regulation, and which is brought about by the interplay between genetic, epigenetic, interactive and environmental factors, at the cellular, tissue and organismal level. Several difficulties appear when one tries to specify the organizational conditions and the terms in which the development and maintenance of such an organization and its evolutionary characteristics should be accounted for. The main objective of this research project is to elucidate and provide a feasible explanation of the overall relation between the developmental organization and its endogenously produced regulation in multicellular organisms. More specifically, this project aims at getting a better understanding of: i). the nature, form and pattern of different types of developmental regulatory mechanisms in an organism; ii). the ways developmental regulation shapes the relation between cells (parts), groups of cells (tissues), and the organisms (wholes) in which they participate; iii). whether the concept of regulation (and which specific regulatory patterns) can be theoretically established as a general principle underlying the exportation of ‘organismality’ from the unicellular to a meta-cellular level; iv). how the nervous system and the respective interactive and environmental regulatory factors contribute, influence and transform the overall pattern for the regulation of development and maintenance; v). the regulatory logic that allows for new forms of complex agency and flexible behavior.