Toward a Model of Investigating “Coordinated Stasis” Through Habitat Tracking in Communities of Digital Organisms

The idea of stable biotic communities that are resilient to disturbance and invasion, and in which evolutionary change may be impeded by ecological interactions, has garnered considerable attention in both theoretical ecology and paleobiology. In the latter field, stable communities are often discussed in terms of “coordinated stasis”, where entire biotic communities may display the canonical evolutionary stasis of punctuated equilibria for significant periods of time. A prevailing hypothesis that has been advanced to explain coordinated stasis is habitat tracking, in which species evolve little as long as they can migrate to regions of habitat containing their optimal living conditions. In this contribution, we describe how we have modified Avida, a proven digital evolution platform, for investigating the habitat tracking hypothesis in a rigorous, experimental manner. We model habitats consisting of spatially localized fields of resources and fixed landmarks, and modified Avida to give its digital organisms capabilities for movement, vision, resource sensing, and resource consumption. Our preliminary results show that while the movement and ecological subsystems we implemented each produce positive outcomes in isolation, they conflict with each other when combined and result in these outcomes occurring infrequently. Nonetheless, the results validate the effectiveness of these additions and set the stage for further habitat relocation experiments, with clear predictions about expected responses.