The key to staying young has been found - by a gelatinous creature in the Mediterranean. The so-called immortal jellyfish Turritopsis dohrni is the only animal that, in an emergency, can avert death.
How does the immortal jellyfish cheat death?
This jellyfish may seem little more than a brainless blob the size of a blueberry, but it has the greatest power of all. When the medusa - the domed, roaming adult form to which the name jellyfish normally refers - is injured or senses a life-threatening situation, such as starvation, it can revert to the earliest stage of its life-cycle - like a granny morphing back into a baby.
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It's an ugly process. Once the invertebrate 'decides" to reboot, it turns inside-out. everting its umbrella-shaped bell and exposing its body cavity. Its insides disintegrate into a cellular slush and it absorbs its ltentacles, losing the ability to swim. By the time it sinks to the seabed it's a featureless glob of recycled cells. The blob eventually sprouts a polyp, the anemone-like equivalent of a larva. And voilà - the jellyfish is reborn.
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The species thus turns back time and gets a fresh start - and not just superficially. Dormant genes switch on while others turn off, orchestrating an organism-wide transformation of cells and tissues. Muscles morph into, say, nerves and skin cells, and the jelly is renewed inside and out.
Furthermore, all medusae can perform this otherworldly about-turn. It is a lifelong talent and the ultimate survival skill.