Potential of longevity: hidden in structural complexity

In order to understand the phenomenon of longevity in biological world, the relationship between the potential of longevity of an organism and its structural complexity is analyzed. I. Potential of longevity is the maximum longevity of an organism if it lives in an ideal environment. Longevity of an organism includes the time for development (developing time) and the time for structure-maintenance (maintaining time). II. The developing time for an organism depends on its structural complexity. The maintaining time is related to two factors: the degree of damage-exposure and the potential of functionality for structure-maintenance. Potential of functionality includes the capacity of basic functionality and the potential of functional compensation. The capacity of basic functionality is built in the structural complexity of the organism. However, the structural complexity and the functionality of an organism will be reduced gradually with age by the accumulation of Misrepairs. Functional compensation can slow down the decline of functionality during aging by two mechanisms: functional substitution and partial regeneration, and theses two functions are also built in structural complexity. Since the developing time and the maintaining time are both determined by the structural complexity, the potential of longevity of an organism is hidden in its structural complexity. Different species’ have different longevities because they have different structural complexities. III. An animal has limited longevity because it has limited structural complexity. Limited structural complexity and limited longevity are essential for the survival of a species. IV. Despite of the same potential of longevity, the individuals of a species have different lifespans. The lifespan of an individual is more related to the degree of damage-exposure, which is determined by the living environment and the living habits of the individual. In conclusion, the potential of longevity of an organism is hidden in the structural complexity, but its real lifespan is determined by the living environment.