| According to the necessary and sufficient conditions for the existence of the center and the global stability of the positive equilibrium in a three-dimensional replication system,a complete classification of the three-strategy cyclic dominance system of the donation game is obtained.By introducing mutation into the donation game,the existence of a small-amplitude limit cycle and a center of the three-dimensional replicator-catastrophe dynamic system is judged.The Permanence for the four-strategy cyclic dominance system is discussed. |