On ESS

Consider strategies S, and S2, with fitness functions wi and wy. Define p as the fre- quency of strategy S. For each of the following scenarios, plot the fitness functions and show where the ESS(s) are. Use graph paper. Case 1: Each strategy does best when it is common. Often the case for cooperative strategies that do best when there are many other cooperators like them. 101 = 0.5 + P W2 = 1.5 - P (1) Case 2: Each strategy does best when it is rare. Often the case for immune system variants, since pathogens are not adapted to rare variants. wi = 1.5-P w2 = 0.5 + P Case 3: S, helps everyone equally, but it pays a fitness cost that Sy does not. Case of a purely altruistic strategy. = 0.8+ P u2 = 1+p (3) Consider strategies S, and S2, with fitness functions wi and wy. Define p as the fre- quency of strategy S. For each of the following scenarios, plot the fitness functions and show where the ESS(s) are. Use graph paper. Case 1: Each strategy does best when it is common. Often the case for cooperative strategies that do best when there are many other cooperators like them. 101 = 0.5 + P W2 = 1.5 - P (1) Case 2: Each strategy does best when it is rare. Often the case for immune system variants, since pathogens are not adapted to rare variants. wi = 1.5-P w2 = 0.5 + P Case 3: S, helps everyone equally, but it pays a fitness cost that Sy does not. Case of a purely altruistic strategy. = 0.8+ P u2 = 1+p (3)