A new analysis of behaviour in a structured population illuminates Darwin’s theories of co-operation and competition between kin, and provides an abstract model that could simplify scientists’ quest to map behaviour among disease-causing organisms within a cell.

The study by Queen’s Mathematics and Statistics professor Peter Taylor, and co-authors Troy Day (Queen’s) and Geoff Wild (University of Western Ontario) presents a simple formula for balancing the benefit and cost in altruistic acts, allowing researchers to predict behaviour and summarize disparate results in a simple framework.

“Although our main focus is on cooperation, these graph-theoretic relationships can apply to the evolution of other traits,” says Dr. Taylor. For example, at Queen’s we are particularly interested in the behaviour of pathogens competing within a host, in their capacity to cause disease, and we expect applications of our results to these models.”

The study titled Evolution of cooperation in a finite homogeneous graph is published in Nature. It provides a system that can be applied to any species within its natural environment to gain an understanding of its behaviour and interactions.

“One can imagine interacting individuals playing a game,” says Dr. Taylor. “With fitness determined by the game payoffs and the competition between offspring for space, our model predicts which strategies will emerge under the forces of evolution.”

The research was funded by NSERC’s program of discovery grants.