The role of bifurcation or structural-phase transitions in the evolution of complex systems is analyzed using a phenomenological algorithm and formalized concepts of adaptability and stability. It is shown that the algorithm makes it possible to estimate the degree of transition harmonicity and the stability of the new state. Knowledge of the features of the most critical zones of structural-phase transitions makes it possible to change the trajectory, pace and ultimate goal of the evolution of various dangerous natural processes by small energy impacts, preventing their development to extreme states. The knowledge of the functional significance of such “acupuncture” points of evolutionary processes makes it possible to control them with minimal energy costs for the purpose of preventive protection.