Borrowed Time: The Science of How and Why We Age

The question of how and why organisms age has teased scientists for centuries. There are myriad competing theories, from the idea that aging is a simple wear and tear process, like the rusting of a car, to the belief that aging and death are genetically programmed and controlled. In fact, there is no clearly defined limit to life, and no single, predictable program playing itself out: different things are happening within and between tissues, and each system or organ accumulates damage at its own pace, according to the kind of insults imposed on it by daily living.  Written by Sue Armstrong.