I think the subject says it all.
One could claim that organisms that reproduce by simple cell division are immortal. After all, neither successor cell can truly be called the offspring in pure cases. So yes, barring accident, they don’t die.
Many ocean invertebrates live until something kills them, but don’t really die of “old age.” At least, I’m not aware of observations to that effect. Things like corals, anemones, and sponges live for hundreds or thousands of years, and only die because of things like predation, sedimentation, climate change, pollution, and disease. Of course, telling where one of those organisms stops and the next begins is somewhat difficult.
Also, fungi and plants that can spread by vegetative propogation are pretty much functionally immortal. Strawberry plants, for instance. Even if you prevented their sexual reproduction, they would continue to spread by sending out runners and thereby living indefinitely.
And, as Qadgop said, pretty much all single-celled organisms can be argued to be several billion years old. When a cell splits in two, which is the child and which is the parent?
Death due to old age is by no means a manditory requirement of life.
-b
Other people have alrady metioned plants. Several species of plant only reproduce asexually and are doing quite well, thank you very much.
Amongst animals starfish are the most complex I can think of that maintain some form of immortality.
Viruses don’t die but are only on the cusp of being alive.
A google search of “are viruses alive” will produce plenty of references such as this.
According to H.P. Lovecraft, pathological liars may be able to enjoy some form of immortality.
I’ve also heard that some trees might not die of old age either, but eventually are killed (similar to the invertebrate organisms mentioned by bryanmcc). Bristlecone pines are claimed to be the oldest living organisms that haven’t reproduced (I mean as opposed to those that clone themselves). The oldest is nearly 5000 years old.
My ninth grade Algebra teacher, Dr. Freedman has always been alive. And, he always will be. Oh, he’s a despicable organism !!!
Fidel Castro
Strom Thurmond
Bristlecone pines are the oldest organisms whose age can be reliably determined. There are a number of tropical species whose ages probably surpass this but that can’t be determined because the constant temperature means no growth rings.
There aren’t any truely “living” organisms that keep their original DNA in their original bodies and live on indefinately in the physical world. About the closest you can come is asexual reproduction or plant runners… cloning yourself. True you might not be able to say which is the original parent in some cases, but these individual cells would eventually die; fast for algae or bacteria, slow for trees. Coral reefs and such do live a long time (decades to several centuries), but their not exactly immortal. You could probably take a fair number of organisms found on Earth who given perfect stable conditions, and complete protection, would stay alive as long as you kept them right. Unfortunately, no region or habitat will remain stable throughout eternity in order to keep an organism alive. We may have 5000 year old trees, but what happened to all the X-million year old trees the dinosaurs munched on or the pond scum that used to flourish in Antartica? Some life forms may have the potential to survive indefinately, but their supporting environments certainly will not hold out as long.
mmmiiikkkeee, I think some distinction should be drawn between functional immortality and literal immortality. Obviously, no creature can be truly “immortal.” The universe had a beginning in the Big Bang, the Earth didn’t form until 5 billion years ago, the sun will die in another 5 billion years or so, and the Universe will eventually die a slow heat death (probably). I think what most of the posters in this thread are referring to is functional immortality: any organism where death isn’t a pre-programmed part of the life cycle like it is in most mammals. If you had a hypothetical eternal environment that maintained the same conditions forever, strawberries would be immortal, but mice would still only live about three years.
-b
Yes, which is why I did say that some organisms have the potential to continue living as long as conditions permit… that are not programed to kick the bucket after X number of moons. However, given the realistic constraints of survival, the overall “long range planning” of any ecosystem runs on the idea that everything will die from something (be it a forest fire, using up all the nutrients in the surrounding soil, or just getting so dam big that the wind blows you over) and be succeeded or overrun by new life, contributing it’s resources back to the system. It’s only in rare cases that individual organisms actually do survive for thousands of years at a time, while most of their neihbors succumb to the rigors of life. I’d look at a 5000 year old tree in a similar way as a 7’ man. Real, yes… lived up to a great potential, yes… common enough to see every day ie - the norm, no. Since the original question was “are there organisms that do not die?”, I’d have to go with no… BUT there are organisms that do not have a specified expiration date, ALTHOUGH the chances of extreme long-life are very slim given that it’s a dog-eat-dog world.