I was reading an article titled "Why can't we live forever" when I came across a graphical sidebar containing drawings of various animals, each labeled with their maximum recorded life spans in the wild.
It was interesting: there was the house mouse (4), the jackrabbit (13), the dog (29), the cat (36), a human (122), the Galapagos tortoise (150), and the koi fish (200). Then I came to the end - the jellyfish and the hydra (a tiny creature biologically related to the jellyfish) - and the graphic said these creatures are immortal!
Say what? Immortal? There are creatures that are immortal? My skeptical genes kicked in. So I turned to my friend, Mr. Google.
It turns out that there are an endless number of types of jellyfish, and most of them live relatively short lives - a few months, say. One rare species apparently can live for 30 years. But scientists have discovered that one species - Turritopsis nutricula - apparently has the ability to switch back and forth between the two stages of its life cycle. One is medusa (the umbrella shape we picture) and the juvenile polyp stage. If they can do that indefinitely, goodbye death.
The hydra stays in the polyp stage. It reproduces by budding. But, in the late 1990s, scientists found something amazing - hydra don't undergo senescence (aging). So if they don't get old, how would they get old and die?
The lesson: If you want to be immortal, just transform yourself into a T. nutricula jellyfish or a hydra. You probably, however, shouldn't bother to bring any beer along.