Coevolution of cooperation and niche construction based on modifications of physical structures of interactions

Niche construction is a process whereby organisms that modify their own or others´ niches through their ecological activities. Recent studies have revealed that changes in social structures of interactions caused by social niche construction of individuals can affect seriously the evolution of cooperation. However, such a social niche also could be changed indirectly by a modification of their physical environment. Our purpose is to clarify the coevolution of cooperative behavior and physically niche-constructing behavior that modify social niche indirectly. For this purpose, we constructed an evolutionary model in which each individual has not only a strategy for a spatial Prisoner´s Dilemma but also has traits for niche-constructing behavior for modifying its physical environment that can limit social interactions between neighboring individuals. By conducting evolutionary experiments, we show that the evolution of cooperation was promoted by the emerged environmental structure constructed by the evolved niche-constructing behavior under the condition that the constructed niche could be inherited in succeeding generations stably. We also discuss effects of ecological inheritance of environmental factors on the evolution of cooperative behavior in detail.