Can we do more with less ? Qualitative discrete-event models of ecological systems and their formal analysis

Maximilien Cosme
Institut Agro Rennes-Angers
Depending on their scales or the abstraction level of their description, biological dynamics can be conceptualized and modelled differently. Traditionally, they are described quantitatively, either in a discrete or continuous scheme. This approach has already proven its worth through abundant theoretical elaborations. However, like any representation, it comes with constraints that limit our ability to model certain ecological objects and phenomena. As a consequence, complementary approaches such as qualitative modelling have emerged. These approaches have found their most significant uses in systems biology, where complex metabolic networks are modelled as discrete-event systems, with genes and other chemical species being expressed or inhibited by their mutual interactions. Despite the widespread use of this description in systems biology, it remains rare in ecology. In my presentation, I will discuss the discrete-event modelling of ecological systems, with an emphasis on the Ecological Discrete-Event Network (EDEN) modelling framework. First, I will briefly introduce the main concepts, their articulation, and the interpretations that can be drawn from this formalism. Then, using various examples, I will demonstrate how specific analysis techniques--such as structural analysis, model-checking, and causal analyses--reveal system properties that remain largely unexplored. In addition, I will discuss some potential applications of this framework to evolutionary ecology. Finally, drawing from the conceptual and methodological richness that blooms at the intersection of systems biology and theoretical computer science, I will advocate for a better convergence of ecology with these two research communities, as their potential exchanges can be mutually beneficial.