The Evolution of Coordinated Cooperative Behaviors (2016)
Cooperative behaviors are useful to many species of animals. Predators may team up to hunt large prey that they cannot catch on their own, while prey can herd together for defense. This dissertation focuses on understanding the environmental factors and cognitive architectures underlying the evolution of coordinated cooperation. An agent-based neuroevolutionary simulation of an ecosystem containing teams of predators and prey was built, modeling the environment of spotted hyenas. Communication, prey-capture rewards and reward-sharing strategies were found to determine whether cooperative hunting behaviors emerged. This simulation was extended to more complex cooperative behavior, that of coordinated mobbing. Through careful coordination, a large number of spotted hyenas can attack a group of lions and successfully steal a kill, even though lions are much stronger. The computational model developed in this dissertation helped understand how spotted hyenas are able to perform this complex cooperative task and how mobbing behaviors evolved. Many factors that were observed affecting lion-hyena interaction and rates of lion-mobbing in nature were also discovered using the model. This model was then used to make predictions about real-life hyena behaviors during mobbing events, which may be verified in the field in future. These results and predictions lead to general insights into how coordinated cooperative behaviors arise in humans and animals. Such insights in turn should prove useful in building cognitive architectures and team strategies for artificial agents in the future.
PhD Thesis, Department of Computer Science, University of Texas at Austin, Austin, TX, August 2016.

Padmini Rajagopalan Ph.D. Alumni padmini [at] cs utexas edu