Aging is one of the few experiences shared across nearly all living organisms, but animals across the animal kingdom have vastly different timelines on how quickly (or slowly) aging actually occurs. Why does a tiny worm live just a few weeks, while a whale can see two centuries? Why do some cold-dwelling species seem to defy time itself, and how have humans managed to nearly double their own lifespans over the last century?
At the heart of these questions lies a fascinating blend of biology, environment, evolution, and choice. There are many layers to aging that can tell us why some factors cause some creatures to be nearly immortal, while others are bound to quick and fleeting lives. What is the pattern of biology in the animal kingdom that makes aging such a strange concept? Click through this gallery to find out.