HEA STEM 2014 Understanding evolutionarily stable strategies: interactive games in the classroom Catherine Dennis
Evolutionarily Stable Strategy? ‘A strategy which, if adopted by a population in a given environment, cannot be invaded by any alternative strategy that is initially rare.’
Pure ESS One strategy adopted by all animals
Mixed ESS Frequency dependent
Aim John Maynard Smith (1973)
Hawk Dove Game
Fight – win or be injured Win Retreat Negotiate peacefully HAWKDOVE HAWK DOVE
Hawk Dove Game Fight – win or be injured Win Retreat Negotiate peacefully HAWKDOVE HAWK DOVE
Hawk Dove Game Victory - Cost 2 Victory 0 2 HAWKDOVE HAWK DOVE
To play the game: Victory = 50 points, Cost = -100 points Victory = 50 points, Cost = 0 50 points 0 points Hawk Dove Game
To play the game: Victory = 50 points, Cost = -100 points Victory = 50 points, Cost = 0 50 points 0 points 10 rounds Hawk Dove Game
V - C 2 V 0 V2V2 HAWKDOVE HAWK DOVE
Benefits Not entirely equation focussed Play both strategies – one species! Evolutionary nature of the game emphasised ACTIVE
Limitations Some students still fail to grasp concept However….. …..they remember game theory ….. all appear to be comfortable with the concept by Level 4
Further activities Spreadsheet exercises in ecology and evolution chapter 39: Evolutionary Stable Strategies ology_evolution.htm ology_evolution.htm Dennis, C. (2014) Teaching the repeated Prisoner’s Dilemma with a non-computerised adaptation of Axelrod’s Tournament, Journal of Biological Education (in press) Extension exercise for Axelrod’s Tournament: cooperative-resource/easy-iterated-prisoners-dilemma/ cooperative-resource/easy-iterated-prisoners-dilemma/