Anyone who has ever looked in the mirror and tried to smooth their wrinkles away might well be jealous of the turritopsis dohrnii. The tiny jellyfish has the ability to regenerate its cells and literally turn back to a more youthful version of itself.
The turritopsis dohrnii is likely unique in this particular talent. But humans’ pursuit of immortality has prompted researchers to study creatures like jellyfish, lobsters, and the infamous hydra in order to better understand what biological means an organism might need to live forever—or, at least, a very long time.
The scientists who study these organisms don’t refer to their specimens as immortal; it’s a decidedly unscientific word. Instead, they study longevity. Regardless, their research inevitably raises philosophical questions about the true nature of immortality. If a being is truly immortal, should it need to eat to survive? Can an immortal being be killed?