I want to be forever young

Aging is thought to be a consequence of intrinsic breakdowns in how genetic information is processed.But mounting experimental evidence suggests that aging can be slowed. To help resolve this mystery, I derive a simple mortality equation that governs the dynamics of an evolving population with a given maximum age. Remarkably, the equation is independent of the choice of fitness function. I solve it analytically and confirm the solution explicitly for three different fitness functions. In a constant environment, programmed aging confers no long-term benefit. But in a changing environment it may be possible that it is favored by natural selection.