Apparently life on Earth has no meaning, the closest thing to a reason to exist is creating as much biodiversity as possible, through reproduction forced as the only achievement every creature can dream to reach.

On Earth, individuality is not valued. Anything can be sacrificed for the good of the species; every individual not capable to reproduce either becomes a pawn of society or dies.

My question is, could nature on another planet work differently? An almost indestructible and biologically immortal creature capable of adapting resistances to almost anything. This creature puts its own survival above the continuity of the species. Could this creature develop naturally without artificial engineering?

If so, what are the conditions for this creature to exist?

  • 3
    $\begingroup$ Have you ever googled water bear? $\endgroup$
    – Dan Bron
    Jun 15, 2016 at 12:18
  • $\begingroup$ those are not biological immortal , they just happen to be really resistant . $\endgroup$ Jun 15, 2016 at 12:20
  • 3
    $\begingroup$ Oh, then you may wish to google turritopsis dohrnii. $\endgroup$
    – Dan Bron
    Jun 15, 2016 at 12:22
  • $\begingroup$ The singular of species is actually species. It's one of those funny words that make English difficult. If that word followed the usual rules, then the singular form would be specy, because -y in singular normally becomes -ies in plural. $\endgroup$
    – user
    Jun 18, 2016 at 22:31

3 Answers 3


Yes, we have some

There are jellyfish, hydra and other relatively simple creatures which have evolved immortality, so the basic answer is yes they can evolve.

But it's not the best evolutionary strategy

Evolution is based on selection, and selection generally requires death. Creatures that do not automatically die are going to be prone to overpopulation problems every time there is a rise and then fall in the amount of food available, and the older an organism is, the more likely it is to meet a pathogen to which it is vulnerable.

So it makes sense for this to work for simple creatures, for whom death is most likely to happen at the hands of the environment or predation, rather than needing their own capacity to survive indefinitely. But for more complex creatures like us, the chances are that a mortal species would out-evolve an immortal one, making it a weakness rather than a strength.

Longevity as a benefit

Having said that, we know that it is preferable to have a long natural lifespan in certain circumstances; when there are few natural predators or the creature has good defenses (tortoise), when there can be long periods without any available food (scorpion, many insects, desert animals). This is because only those species which can make it through a long drought have previously survived these events, so they are necessarily the only ones which are still around.

The Defensive Individual

It is conceivable that a species living on a planet or large moon with a specifically periodic toxicity (e.g. a periodic tidal event between moons, or orbiting a binary system with occasional eclipses, or even just very infrequent floods as we have in the desert) could develop both a lack of mortality (per Earth species) and also a periodic lifecycle, in which the main mode is pure survival with no opportunity to reproduce, and occasionally a period of plenty.

Perhaps a good model for this is the scorpion; it lives in deserts that are inhospitable, is well protected and capable of withstanding even nuclear fallout. It still occasionally reproduces, presumably when there is enough food around for the gestation.

We also see the phenomenon of an apparently bare desert exploding into life after the rains, capturing water and germinating as rapidly as possible before the water disappears. So the life of a scorpion-like creature would be mostly a defensive and slow-moving one, seeking preservation over all else, with brief periods of plenty when everything changes and reproduction is possible.

If you want to include an adaptation phase, it could be conceived that a highly effective immune system which defends the creatures during droughts from pathogens (perhaps it is windy and pathogens spread easily?) is then able to share antibodies during the social/reproductive phase via bodily fluid transfer. This would be like a mother provides protection to her unborn child; these creatures could swap pellets of 'blood' or other fluid, thus providing protection within the species for the bearer of your children.

No man is an island, but a man-o-war is a floating ecosystem

No animal can survive entirely alone; it always has a chance of dying so reproducing is the only sensible protection against being in the wrong place at the wrong time.

But what about a colony-type organism, like a man-o-war jellyfish? It is a system of millions of organisms, providing different things. Collectively, I can envision something where individual organisms live and die and evolve, and the strongest get to stay on the mother body; this would be adaptable but without partner, and survival would be everything.

I can't imagine that any organism would be entirely alone, but if reproduction events were very rare, and this gestalt existence was the norm, it would very much feel like the organism was alone. If the life cycle involved the sentient part dying before meeting any progeny, then each consciousness would believe it was a god; born from nothing, living alone, and being unaware of death.

Until it meets some oracle which its ancestors left for it to learn the long and lonely story of their history.

  • $\begingroup$ +1 for "mortal species would out-evolve an immortal one". Longer lives means low birth rates, which in turn means slower evolution and less adaptability $\endgroup$
    – Kys
    Jun 15, 2016 at 13:53
  • $\begingroup$ +1 for the man-o-war floating ecosystem part! I think one body made up of tons of other organisms makes a lot of sense. $\endgroup$
    – Martin_xs6
    Jun 16, 2016 at 19:05

First off, nothing ever, ever, ever does anything "for the good of the species". Evolution is all about vested self-interest, cost-benefit payoffs and expending minimum effort to obtain maximum gain. A fox in my home town is unaware that the town down the road even exists, let alone that there are other foxes in that other town. The fox's personal activities do not impact what happens in that other town. The fox and the genes inside the fox cannot conceive of "the species".

Resistance to almost anything is also a tricky one. Evolution can't anticipate, it can only deal with the here-and-now and with the comes-along-regularly. So a tree can store enough nutrients to get through the winter, but it can't store enough to get through an ice age. Especially if a 2 mile thick ice sheet ends up on top of it! :-) To be immortal throughout geological time, your creature will have to be able to cope with extremes of climate, radical changes in the chemical or physical composition of what it eats (Yuck this grass is chewy and full of silica! I miss trilobite stew!), things with sharp pointy teeth trying to snack on it, and all sorts of unexpected side effects of what the rest of the biosphere is up to. For instance, someone once suggested that the dinosaurs became extinct due to hayfever from the evolution of flowering plants. Unlikely, but it shows that something unanticipated can evolve and throw you off your game. It might survive a billion years and then discover it is allergic to bee stings.

Julie Czerneda's Webshifters series (Beholder's Eye is the first volume) has an immortal species. She does it by making them shapeshifters (who obey the law of conservation of mass - they have to take on or dump mass to change size). That species has a repertoire of forms to survive different conditions. They more fantasy bit is that they can also do mass-energy conversions, to provide a propulsion system in space. Don't stand next to one when it does an emergency shape-shift to something smaller, as it will release water vapour, carbon dioxide and a loud bang of energy!

  • $\begingroup$ 2 mile thick ice sheet ends up on top of it! - that rocks )) *Evolution can't anticipate, it can only deal with the here-and-now and with the comes-along-regularly. * - very true $\endgroup$
    – MolbOrg
    Jun 19, 2016 at 0:23

A rock:

Life is defined as the period between birth and death if something can't die it isn't alive. If it can't die that means no processes are vital, meaning it may not have any processes, making it inanimate. If you just mean something that could survive millions of years, have a very hearty organism that reproduces with no genetic change, cloning its self, but rather or not that is the same organism depends on your opinion.


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