Background fitness, eco-evolutionary feedbacks and the Hawk-Dove game
This paper further develops work from a previous article which introduced a new way of modelling evolutionary game models with an emphasis on ecological realism, concerned with how ecological factors determine payoffs in evolutionary games. The current paper is focused on the impact of selectively neutral factors (i.e. those that are the same for all strategies), such as background fitness and a neutral density dependence on game dynamics. In the previous paper background mortality was modelled by post-reproductive mortality describing aggregated mortality between game interactions. In this paper a novel approach to the modelling of background fitness, based on different occurrence rates (intensities) of game interactions and background events is presented. It is shown that the new method is more realistic and natural for dynamic models than the method used in the previous paper. The previous method in effect produces biased trajectories, but it is compatible with the new approach at the restpoints. Also in this paper a rigorous stability analysis of the restpoints of the dynamics is presented. It is shown that the stability or instability of the restpoints, can be explained by a mechanism of eco-evolutionary feedback. The results obtained are illustrated by a Hawk-Dove game example.