What are the two main biological theories of aging?

The two main biological theories of aging are indeed often categorized as the Damage theory and Programmed theory. The Damage theory encompasses a range of approaches that suggest aging results from the accumulation of damage to cells and tissues over time. This can involve oxidative stress, DNA damage, and other forms of cellular injury that gradually impair biological function. Essentially, as organisms age, they accumulate various forms of damage that ultimately lead to functional decline.

On the other hand, the Programmed theory posits that aging is a genetically predetermined process, where certain genes control the rate of aging and the occurrence of age-related changes. This theory includes concepts like the telomere shortening hypothesis, which suggests that the number of cellular divisions a cell can undergo is limited, ultimately leading to aging when these limits are reached.

Together, these theories provide a comprehensive understanding of the biological aspects of aging by highlighting the interplay between random cellular damage and the genetic programming that governs life's duration.