We’ve always been told that immortality is just fiction and is only real in SF movies or books, but does it actually exist?
As time passes, all living organisms slowly fall apart and this action is called senescence. But does this really include ALL living things? Senescence is a process in which cells stop dividing and gradually die. This doesn’t apply to some species of animals, plants and fungi whose existence isn’t threatened by ageing and can live for hundreds or even thousands of years. Their longevity is thanks to the fact that they don’t experience senescence or their body is simply able to repair their DNA. How interesting is that? Here are some of the lucky species:
Turritopsis dohrnii, the undying jellyfish
The normal, everyday rules don’t apply to this species and it seems to have found a way to cheat death. This spectacular jellyfish has the remarkable ability to hit the reset button whenever under impending threat, wounded or experiencing starvation. Turritopsis dohrnii is a small jellyfish, about 4.5 milimeters long and wide, part of the group called Cnidaria, which can reverse its life cycle.
It begins its life by being a free-floating larva which attaches to a hard surface (e.g. boat, rock, shell), then matures into a plant-like polyp. From there, multiple young jellyfish are developed and then liberated to swim free, growing into an adult specimen called medusa. When under threat or on brink of death, the medusa shrinks in on itself, ingesting its tentacles and losing the ability to swim. It then attaches itself onto a hard surface, rebecoming a polyp and the development process repeats itself. Although they can’t die from growing old, jellyfish have quite a large number of predators such as fish, turtles, sea slugs, etc.
Ever-growing lobsters
As I’ve previously said, we are made to degrade in time. This action happens at a cellular level: the cells in our bodies stop dividing, yet remain active and alive. In time, they get slower and tend to make more errors, resulting in our ageing. Lobster’s cells don’t work that way. They have a special enzyme , telomerase, which assures their cells don’t age. The lobster’s cells never enter senescence and thus, they don’t grow old. That doesn’t necessarily mean they have an easier life than us: as crustaceans, they have their skeleton on the outside and because of their bodies’ continuous growth, they constantly outgrow their shell. This means they have to abandon their old exoskeleton and regrow another one. This process is quite frequent and consumes a lot of the lobster’s energy, often resulting in them dying of exhaustion. In one way, they are immortal as they don’t age, but there are multiple factors which lead to them dying.
There are many other animals and plants which are proof of immortality existing in our own world. Scientists have yet to find out how these species’ longevity could help humankind in the battle with diseases and natural phenomenons.
Bibliography:
Comentários