Augmenting artificial development with local fitness

In biology, the importance of environmental feedback to the process of embryogenesis is well understood. In this paper we explore the introduction of a local fitness to an artificial developmental system, providing an artificial analogue to the natural phenomenon. First, we define a highly simplified model of vasculogenesis, an environment-based toy problem in which we can evaluate our strategies. Since the use of a global fitness function for local feedback is likely too computationally expensive, we introduce the notion of a neighbourhood-based ldquolocal fitnessrdquo function. This local fitness serves as an environmental-feedback guide for the developmental system. The result is a developmental analogue of guided hill-climbing, one which significantly improves the performance of an artificial embryogeny in the evolution of a simplified vascular system. We further evaluate our model in a collection of randomly generated two-dimensional geometries, and show that inclusion of local fitness helps allay some of the problem difficulty in irregular environments. In the process, we also introduce a novel and systematic means of generating bounded, connected two-dimensional geometries.