This work addresses the question of whether collective sensing allows for the emergence of groups from a population of individuals without predetermined behaviors. Experiments are run in an agent-based evolutionary model of a foraging task, where the fitness of the agents depends on their foraging strategy. Agents compete for the same limited resources and neither the environment nor inter-group dynamics benefit groups over individuals. The foraging strategy of agents is determined by a model-free neural network, which leaves agent behavior unrestricted.
Experiments demonstrate that gregarious behavior is not the evolutionary-fittest strategy if resources are abundant, thus invalidating previous findings in a specific region of the parameter space. In other words, resource scarcity makes gregarious behavior so valuable as to make up for the increased competition over the few available resources. This result is obtained with a model-free approach which allows evolution to select from an unconstrained set of behavioral models. Furthermore, it is shown that a population of solitary agents can evolve gregarious behavior in response to a sudden scarcity of resources, thus individuating a possible mechanism that leads to gregarious behavior in nature.
Keywords: Collective Sensing, Foraging, Group Behavior, Neural Networks