No, this isn't a Benjamin Button publicity stunt -- this is more akin to scary science-fiction. Scientists have just identified a 5mm-long jellyfish they call Turritopsis Nutricula, originally from the Caribbean but soon to be everywhere, which has the ability to "return to a juvenile state" after multiplying. According to the Smithsonian Tropical Marine Institute, this is the only known animal which is capable of quite literally reverting to its younger self, through a cell process called transdifferentiation.

"Scientists believe the cycle can repeat indefinitely, rendering it potentially immortal," the Telegraph reports. "We are looking at a worldwide silent invasion," one marine scientist said. Almost as striking as their disturbing ability to forever renew themselves is the fact that the animals weren't always this way -- they developed this ability over time, "stumbling across the font of eternal youth" in the natural course of their evolution as a species. Is that the future of evolution, one wonders?

Of course, there's always a bright side to biologically perverse anomalies like this one: scientists will have the chance to study and learn from it. On the other hand, if you think an immortal 5mm-long jellyfish is frightening, immortal human beings are likely to be much moreso! Stay tuned -- more on immortal jellyfish as our understanding of them deepens.