The genes of a jellyfish show how to live forever

eternal life (and sponsorship of startup companies in this field suggests there are several of them around) could do worse than study , known colloquially as “the immortal jellyfish”. It is not quite literally immortal. Individuals of the species do die. But those that live long enough can rejuvenate and, having done so, go through their whole lifecycles again. And again. And again. As is true of most jellyfish, that lifecycle includes a sedentary, asexual stage, known as a polyp, and a swimming, sexual stage called a medusa. Larvae produced by sexual reproduction then develop into the polyps of the asexual stage. But can generate polyps in another way, as well, by the reduction of a post-reproductive medusa to a cyst that then gives rise to one.