As far as scientists know, there is only one animal on Earth that has achieved what some (secretly, all?) humans dream about: immortality. Unfortunately, it’s probably not the kind of animal you want to be—just a soft-bodied, neuronally challenged, jellyfish-like creature called “Turritopsis nutricula.” Aside from swimming in the sea, targeting microscopic plankton, a Turritopsis doesn’t do much. It does have sex, but it’s the disembodied, spawning kind. Males release sperm near a female, and the sperm join up with eggs inside her stomach. The fertilized eggs hatch into larvae, called planulae, which settle on hard surfaces—most often rocks—on the sea floor. There, they grow into branching, colonial creatures with budlike polyps that form new, individual jellyfish—beginning the cycle again.
In other related species, adult jellyfish die immediately after reaching sexual maturity and releasing their eggs and sperm. Not so the Turritopsis. It happily reverts to its youthful polyp stage. It does this via a neat trick called transdifferentiation, during which it converts the cells of its umbrella and tentacles into a twiggy colony ready to produce baby jellies once more. Think about it: One moment, you’re a sexually spent adult; the next, you’re a budding youth about to enjoy life all over again.
Bacteria and some social insects, too, can keep on going, perhaps indefinitely. But these aren’t individuals like Turritopsis nutriculae. Rather, theirs is an immortality on a colony-wide scale. It could be, some scientists think, that certain army ant colonies may have persisted for tens of thousands of years or more. The individual ants, workers and queens have changed over time, but their clones live on—with each colony living, hunting, reproducing and then dividing, amoeba- like, into a twin …endlessly.
Plants also have death-defying tricks, turning bits and pieces of themselves into fresh, young copies. Or they act like Methuselah and simply live so long—4,000 years for a bristlecone pine—that from a human’s perspective, they might as well be immortal. Near my home in Oregon, there’s a white pine that sprouted just about the time George Washington set about liberating us from the British. The tree is nearly 300 feet tall, 28 feet in circumference, and shows no sign of dying.
And then there’s the death-be-damned plant in my front bay window: a tangled, snaky epiphyllum—or more simply, an orchid cactus. In the wild, these plants grow in the crowns of tall rainforest trees. But in my home, it’s a reluctant captive, its long, fleshy, swordlike leaves splaying up and out in all directions. “If you get too close,” the waving green blades seem to say, “I’ll poke you right in the eye.”
My husband hates this plant. He has cursed it and wishes it would die. It won’t—not even when I’m away and he forgets to water it. Then, it merely becomes quiescent: The blades droop a bit; the edges curl back and shrivel. But they all spring heartily back to attention with the first splash of water. And even if what’s in the pot in my window did die, the plant would still live: The blades regularly break or drop off and start sprouting roots, searching for a new home. The trick works: I always give in and gather up the young plant like an injured thing, then give it some soil, some water, my care.
They are clones, of course, youthful versions of their older self, and they stand green and juicy in jars and bottles on my windowsills. Sometimes, I hand them off like prizes to my friends. Why would they want them? Because they’ve seen the flowers, each one a huge, voluptuous, pink concoction with long, fringed petals opening wide around a tubular, rosy throat. So gorgeous, so mesmerizing is each bloom that even my husband’s heart softens at the sight. “Incredible,” I once heard him murmur as he reached out to touch a silky petal.
The orchid cactus has lived with us for almost 30 years now. But it was already 80 years old or older when it entered our lives shortly after our wedding. My father, a man who loved plants, brought it to us one day. “Here,” he said, handing me a single blade wrapped in newspaper. “My mother grew this plant, and she gave me a cutting a long time ago. This one comes from that same plant.”
The flat, wizened blade was a family heirloom!—one that if treated kindly, would endure for our lifetimes and beyond. In fact, imagining handing off blades of our own to future descendants, I told my husband this orchid cactus had the possibility of living forever … or at least for a very long time. “Ah, our own Immortal,” he teased.
But all this raises the question: Why them and not us? What twist of fate conferred immortality on a jellyfish, of all things, or edged the bristlecone pine into the longevity record book? Or gave the orchid cactus and many other plants (including a 9,550-year-old spruce in Sweden) the ability to reproduce and defy death by cloning itself? And really, those long, endless lives seem so wasted: The organisms aren’t even conscious. They have no awareness of being dead or alive.
One can pout or curse the gods—or turn to Charles Darwin. Darwin did not know about the Turritopsis since its longevity wasn’t discovered until the 20th century. But like any good gardener, he would have known how to take cuttings from plants to make clones. And so he knew that life could be extended in peculiar ways. He also knew that life is not fair: Disease carried away a beloved daughter when she was only 7. Her death left him bitter, doubting that any god who would sanction such a thing could exist. Yet he didn’t fret about his own aging, even as he chronicled his ailments and changed from a young man able to climb the Andes to one bent and white with age.
Darwin didn’t address the issue of immortality, didn’t write about the possibility of life after death or speculate about how his theory of evolution would affect the many religions that are based on this hope. Some writers have argued that he must have known what his theory meant to such beliefs: In a world driven by evolution, immortality is impossible. Many have cursed Darwin for, as one writer put it, “celebrating death over life.” They are wrong.
What Darwin loved most was life itself, in all its shapes and glories. He wondered how so many beetles, birds and bats had come to grace our planet, and he found the answer, and it had nothing to do with fates or gods. The Earth was not a static place, he realized, and as it changed, as ice ages came and went, and seas rose and fell, plants and animals faced new challenges. Those that adapted left descendants. Those that did not vanished forever. Immortality was not the goal, the reason for being.
How could it be? What purpose would it serve? Where would the many fabulous species that filled the forests, seas and skies be?
If Darwin had met a Turritopsis, I think he would have marveled at its extraordinary life and lifespan. A great observer, he would have described its every detail. Surely, he would have devised some experiment for it, searching, perhaps, for the clues to transdifferentiation as other scientists are doing today. But his true quest was seeking an explanation for what generated new life, for the forces that produce Earth’s “endless forms, most beautiful.” In that long, as yet unending, parade of life’s many species—whether extinct, alive or yet-to-come—there is a continuity and grandeur at least as great as any vision of immortality.
As for the Turritopsis, you can see the jellyfish on YouTube these days. It even has a Facebook page and a Wikipedia entry, and it seems well on the way to achieving yet another kind of immortality that is also beyond the reach of most of us: stardom.