Time is directional, and problems flow from the past to the future. This is the arrow of time. In the process of biological evolution, the past and future of time are asymmetric, which is an irreversible process. But the time arrow and entropy of biological evolution Increase are different. Entropy increase means degradation, that is, the decomposition and decline of old things; while evolution is the industry and development of new things, its time arrow points to the decrease of entropy. therefore(). ['There is only one direction for the evolution of living things.', 'The evolution of organisms can be divided into two categories: degradation and evolution.', 'Biological evolution took a short time in the past and a long time in the future.', 'Changes in entropy are non-directional.']