Summary: Why Do We Age? Scientists answer the question with the latest evolutionary theory of aging, the disposable soma theory, which supports the longevity benefits of calorie restriction. With commentary by leading geroscientist, Tom Kirkwood. [This article was updated Feb 23, 2018, and first appeared on LongevityFacts. Author: Brady Hartman. ] The process of aging, or growing old, seems to contradict Darwin’s theory of evolution at … Continue reading Why Do We Age? The Disposable Soma Theory Answers the Riddle.