Can anything live forever?

Immortality can be a curse rather than a blessing – as Tithonus learned to his cost. This mythical Trojan prince was so handsome that he bewitched Eos, the goddess of dawn. She successfully petitioned Zeus to grant Tithonus immortality so she could be with him forever.
 But Zeus interpreted her request literally. Tithonus didn't die, but he did age. He lost his good looks and his faculties, and Eos lost her interest. She eventually shut him away in a room where he babbles endlessly. It's just a story. But as is often the case, truth turns out to be stranger than fiction.
Plenty of species really are technically immortal. And unlike Tithonus, many are eternally youthful to boot. "Immortal really means you don't die at all, which is stupid," says Thomas Bosch at the University of Kiel, Germany. Paradoxical though it might seem, biologically immortal organisms are definitely mortal. They can be killed by a predator, a disease, or a catastrophic change in the environment such as an erupting volcano. But unlike humans, they rarely die simply because they get old. To put it another way, biologically immortal organisms do die, but they don't seem to age.
They're basically the exact opposite of Tithonus. 

The bristlecone pine is a good example.

  continue reading