Past exam of the mathematics course of the University of Cambridge / 2010 / iii / Paper 35 / 6 / i

Take pure Hawk, $p^{\ast }=1$. For every mutant $p<1$, the payoff difference against an all-Hawk population isThe strict first condition of the two-condition criterion for evolutionary stability holds for every mutant. ThereforeThis conclusion holds even without the usual positivity assumption on the two parameters.