The concept of immortality is one of the oldest tropes in literature. The first written work we have, the Epic of Gilgamesh, tells of a quest for the flower of immortality, which can bring the dead back to life. Whether the resurrected person will continue to age and eventually die again, isn’t made clear. In the meantime the flower allows him to escape from death.
Humans are born to die, but they can’t stop thinking about ways to prolong their lives indefinitely. Perpetual youth is not always a given. Tithonus in Greek myth and Jonathan Swift’s fictional Struldbrugs go on and on, growing older and older and more and more incapacitated. Tithonus in the end shrivels into an insect.
Staying young forever is much a more popular choice. Gods and elves, immortals à la Highlander and the vampire mythos, represent various manifestations of undying youth. Many of them can be killed, but left to themselves, they never age or die.
I could go on about this, and many others have, but this is the SFF Bestiary. What about animals? Not mythical beasts but real, living creatures. Can any terrestrial animal be immortal? Is it even possible?
Lists of “immortal” animals, such as this one, stretch the definition of immortality to include animals that live significantly longer than humans, including my favorite, the Greenland shark. By that definition, a human is immortal compared to a mouse or a fruit fly. What about genuine immortality? Actual deathlessness?
Most terrestrial organisms have an expiration date. Their lives begin in some fashion (born, hatched, budded, whatever). They mature, they reproduce, they age, they die. Their cells stop replicating, their systems deteriorate. Eventually they stop living.
Very long-lived animals tend to have slow metabolisms. They grow slowly. They often move slowly—as witness the giant tortoise and our favorite shark. They mature late. They live their lives in slow motion.
Those lives do end. Eventually they succumb to age, as humans do. But much more gradually.
The big fancy animals, the marquee animals, are mortal, even if they can live for centuries. But there are animals that, as far as we can tell, actually do not die. They’re not vertebrates. In human terms, they’re downright alien.
One way to live forever is to reach a certain point in the life cycle and then start over. Reach maturity, and then, under certain conditions, become a larva again. A tiny jellyfish, Turritopsis dohrni, does exactly this. Scientists call it the immortal jellyfish.
The process is called transdifferentiation. The mature animal reverts to its immature form. It’s not like an adult human becoming a child again; the two forms are quite different. As the article puts it, it’s as if a butterfly could change back into a caterpillar.
In theory there’s no limit to how often the jellyfish can transdifferentiate. Barring accident or predation, it won’t die. It keeps on living, shifting from one form to another. There’s a kind of poetry in that.
Transformation is one way to live forever. But there’s even tinier aquatic organism that may be truly immortal. It’s called the hydra: a minuscule relative of the jellyfish and the sea anemone. Its columnar body has a mouth on top surrounded by tentacles; the bottom or foot can stick to a surface or glide slowly along, or it may bend and somersault through the water. It can shrink to a dot or stretch to as much as two inches (5cm).
The hydra reproduces by budding, basically cloning itself. It doesn’t appear to age. Its cells replicate continuously, without deteriorating, but also without the kind of runaway growth that in humans is called cancer.
In its way it’s a perfect organism. It’s sublimely simple: a foot, a mouth, and a set of tentacles to sting its prey. It isn’t really born, and it doesn’t die. It just is. For as close to ever as anything in this world.
God or Elf or Immortal it’s not. It won’t star in an epic fantasy, unless you size it up enormously and turn it into the mythological monster it’s named after. But it’s a kind of miracle.
I’d love to know of genre works that feature unusual variations on immortality. I’ve seen the Elves, the vampires, the various flavors of immortals. Body-swapping is a popular theme; so is cloning a new body and transferring the consciousness. And of course there are all the variations on electronic and digital preservation of the human mind and personality. What else have writers (and filmmakers) done with the concept? What new ways have they found to make their characters—human, animal, alien, terrestrial—live forever?
The Companions in Mercedes Lackey’s Valdemar series have the ability to reincarnate- either as Companions or Heralds. I’m not sure how much the ordinary Companions remember from life to life, but the two Head Companions definitely do. (They rotate the job- one dies, the other shows up)
Yes! I’ve actually written a story about that for one of the Valdemar anthologies. It was a lot of fun to do.
The more I think about the implications of immortality, even the eternal-youth variety, the less desirable it becomes.
There was, and it is annoying me that I cannot recall the title or author, an older SF work that featured one of those settings that’s supposedly thousands of years in the future while appearing almost unchanged from the present. It turns out that this isn’t a world building flub but the outcome of a cognitive side-effect that should have been caught in testing.
Some of the stories of the Flying Dutchman might qualify. Tom Holt has one, I know. Although I don’t think he ends up dying after all. Also, isn’t Jo Walton’s “Lent” somewhat about this?
Only a teeny bit of a tangent, but Agent Cormac in Neal Asher’s Polity series (spoiler warning here if you haven’t read) thinks he’s unkillable, if not precisely immortal, but it turns out he’s simply cloned without his knowledge each time he dies, and the replacement – complete with uploaded memories from close to the time of death – is sent to carry on the job, unknowing.
Ah, that would have the same problem my solution to the James Bond casting issue* has: if his stored memories don’t include deaths, then they have a strong survivorship bias. Which means he never learns why his worst ideas were bad.
* MI6 got their hands on Joe-90’s BIGRAT.
Ursula Le Guin’s story, Island of the Immortals, has a version of immortality I don’t think I’ve ever seen anywhere else.
Can you remind us? I can’t remember if I’ve read that one.
In R.A. Lafferty’s story “Nine Hundred Grandmothers”, the Proavitoi don’t die. “It is a foolish alien custom which we see no reason to imitate.” They just gradually get smaller and smaller, and sleepier and sleepier, and eventually end up on a shelf in a back room, only waking up for holidays and anniversaries.
It’s one of more attractive versions, at least to me.
Kind of like the immortal jellyfish. Or Tithonus.
In Laumer’s 1961 “Hybrid”, a nebbish is transformed into a nigh-superhuman manly man of mannish manliness, in exchange for becoming the host for an alien parasite and also the means by which the parasite will reproduce. Part of the deal, as I recall, is that after a thousand years of sowing wild oats, the host will become a very long-lived tree. My reaction at the time was that he’d better be very sure he likes his view before setting down roots.
I know that this column is focused on animals, but I just wanted to put in a plug for very long-lived plants, as well as single-celled microoganisms. Some (but not all) single-celled microoganisms undergo fission of one “mother” cell to 2 genetically and physically identical “daughter” cells, potentially indefinitely, and so current individuals could be considered millions of years old.
Right, isn’t there an amoeba that’s been going since the dawn time? And there’s the aspen, which can live underground for centuries, putting up shoots pretty much perpetually.
I wonder how long those massive fungal colonies last?
Something I only appreciated after reading a book about the change to North American ecosystems after the most recent ice age: there are across the continent communities of trees that can no longer reproduce by conventional means, as conditions have changed too much. They can, however, persist by cloning, and as implied by the fact that the reason they have to do this is because of the end of the ice age, the communities last a long, long time. Pando in Utah may be 16,000 years old.
So, a question that came up in the context of an Icons character who could by the grace of a Mesoamerican god turn himself into a human-mass worth of angry humming birds: what’s the lifespan of a bird flock? I couldn’t work out the right phrase to find the answer. Do the descendants of birds in a flock continue to flock together or are they a sort of ad hoc clustering that changes from year to year?
Your various comments here are intriguing. I would be curious about the birds, too. We know that cetacean matrilines can go on for quite a while, with the matriarchs living up to their 60s and 70s, but they tend to split when they get to a certain size. Not sure if birds would do the same.
I have a flock of blackbirds that have been visiting my property for decades. There are almost always eight of them, but every so often as many as three dozen will show up. I swear they come for the holidays, because they’re almost always here in full force at those times of year. Like right now, there are about 20, just in time for Thanksgiving.
The Irish story “The Children of Lir” has four siblings turned into a flock of swans and condemned to flap about as such for centuries. Each individual swan, however, retained its identity for all of this time.
The story’s retold in Gene Wolfe’s Peace.
The flock of Theseus?