Modelling evolution of risk-aversion and extreme altruism

All students and staff welcome.

Speaker

Dr R Mike L Evans is a theoretical physicist working in the School of Mathematics, University of Leeds. He is interested in mathematically modelling the physical world, to discover the simple principles governing complex systems.

Abstract

As physicists, we know that large collections of interacting atoms can have non-trivial emergent behaviour, such as freezing, ferromagnetism and superfluidity. Similar ideas can be applied to large collections of interacting organisms to model non-trivial results of Darwinian evolution. 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 show how 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 instead minimizes 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.

Refreshments

Meet at 16.30 in the Nucleus Building foyer for tea and cakes prior to the talk.