Dr. de Roos’ research focuses on the relationship between individual life history, in particular ontogenetic (i.e. size-specific) development, and the dynamics of populations and communities. Textbooks in ecology define population dynamics as the fluctuations in time and space of the number of individuals in a population. This definition implies that only the life history processes of reproduction and mortality determine population dynamics, as these processes change the number of individuals present.

The main body of theory concerning population dynamics and community structure is hence based on the analysis of unstructured, Lotka-Volterra type population dynamic models, which ignore differences between individuals. Yet, all individual organisms of all species on Earth develop during life from the moment they are born till the moment they die. In between these individuals might reproduce, but the majority generally does not. Hence, after mortality ontogenetic development can be considered the most prominent life history process. Changes during ontogeny result in individuals playing a different ecological role in the different stages of their life history.

In this Math Colloquia André will expand on the mathematics behind the idea of ontogenetic symmetry (i.e., where juveniles and adults compete for resources equally, regardless of differences in body size or resource needs) and illustrate the implications for the community-level consequences (emergent Allee effect etc.) using the simple 3 ODE model.

Dr. de Roos’ seminars and engaging for both mathematician’s and biologist’s alike. He does a fantastic job of illustrating why and how theory can be applied to address key challenges in both basic and applied biology.