Thursday Seminar: Lucas Mathieu (Team Pradeu/Lemoine)

Project entitled: “Exploratory mechanisms, evolution and adaptive immunity: A modelling approach to existing hypotheses”. Resume: What is the common point between clonal selection in the adaptive immune system, central-place foraging in animals, and obstacle avoidance in plant root systems? Perhaps an algorithm: First producing a large range of variation, then evaluating the variants that performed well using an internal or external criterium, and finally reproducing or maintaining the good variants. Crucially, this must occur within an organism (or selective unit)’s cells or sub-units, and during its lifetime. We use the term “exploratory mechanisms” to designate biological systems that are described by this algorithm and ask why and when organisms maintain those processes that learn by producing high variability, despite the very high cost of poorly adaptive variants. Using genetic algorithms, we investigate hypotheses on the evolution of specific processes and evaluate whether their assumptions are realistic, and how evolutionary explanations can be transposed (or not) across instances of exploratory mechanisms in various systems and in various species. For instance: Did adaptive immunity arise in vertebrates to care for symbionts and commensals? By learning from these methods, we try to answer more general questions about exploratory mechanisms and evolution, e.g: How do exploratory mechanisms evolve? How can they influence evolutionary trajectories? To what degree do they confer agency on organisms?