Universal fitness dynamics through an adaptive resource utilization model

Abstract

The fitness of a species determines its abundance and survival in an ecosystem. At the same time, species take up resources for growth, so their abundance affects the availability of resources in an ecosystem. We show here that such species-resource coupling can be used to assign a quantitative metric for fitness to each species. This fitness metric also allows for the modeling of drift in species composition, and hence ecosystem evolution through speciation and adaptation. Our results provide a foundation for an entirely computational exploration of evolutionary ecosystem dynamics on any length or time scale. For example, we can evolve ecosystem dynamics even by initiating dynamics out of a single primordial ancestor and show that there exists a well defined ecosystem-averaged fitness dynamics that is resilient against resource shocks