Modelling evolution of risk-aversion and extreme altruism

Mike Evans, University of Leeds. Part of the Leeds Applied Nonlinear Dynamics seminar series.

Title: “Modelling evolution of risk-aversion and extreme altruism”

Abstract: All organisms descend from populations with limited resources, so it is clear why evolution should select strategies that win resources at the expense of competitors. Less obvious is how altruistic behaviours evolve, whereby an individual helps others despite expense to itself. 

I will describe the principles of Evolutionary Game Theory and how shows that extreme altruism can evolve when payoffs are very rare compared with death. In these states, agents (representing organisms) give away most of their wealth (representing natural resources).

More generally, I will explain a new theorem for evolutionary models, showing that, when pay-offs are rare, evolution no longer selects strategies to maximize income (average pay-off), but to minimize the risk of missing-out entirely on a rare resource. Principles revealed by the theorem are widely applicable, where the game represents rare life-changing events: disasters or gluts.