The legendary Trojan prince was so beautiful that Eos, the goddess of the dawn, was enthralled. She was looking him to be at her side forever, so she asked Zeus to granted him immortality. However , Zeus interpreted literally his request. Titono didn´t die ; but aged , losing his physical charm , his powers and the interest of Eos. Finally , the goddess locked him in a room where he babbled endlessly.
It's just a leyend of Greek mithology, but it shows clearly a paradox :
The Inmortally can be a Curse instead of a Blessing".
Moreover; paradoxically speaking, "biological immortal bodies" are clearly "mortal".They can be killed by a predator , disease, or a catastrophic changes in the environment. But unlike humans, they rarely die from getting old .
- Turritopsis Nutricula: this is the only animal in the planet that can´t die, that can live forever. And it doesn´t mean that it gets old, but it experiences something fascinating and strange " when it gets old it becomes young again". When the sperms and eggs of the jellyfish come together, they form a tiny larva, that it doesn´t simply enlarge to an adult , but adheres to a hard surface and becomes a soft structure called polyp. Often, those polyps produce minimal clones, as hydra. But in some species, those polyps produce male or female small jellyfish swimming freely . They become adults and produce sperm and eggs . Then, the cycle begins again. Most jellyfish can reverse their development in almost all the various stages of their complicated life cycle, but by becoming a sexually mature adult lose the ability to turn back the clock . The immortal jellyfish disobeys the fundamental role. Even a sexually mature adult can become a polyp again ."It´s like a butterfly that becomes suddenly a caterpillar".
- Hydra: it is a soft-bodied animal , related to jellyfish and it usually measures just 15mm .The lack of cellular aging is due to the stem cells. The hydra has such a powerful set that in case of an accident, it can grow parts of its body.This ability earned its name, inspired by the Greek mythological Hydra of Lerna, that developed heads when it was decapitated. It was an ancient and ruthless chthonic water monster with many-headed serpent -shaped (the number of heads ranging from three, five or nine to one hundred , and even ten thousands)The regenerative powers of the royal hydra are crucial during playback, which is often not sexual, but occurs in developing tiny clones of itself.Hydra uses three distinct populations of stem cells to replicate all the various tissues that form. It is unclear how the hydra prevents age and particularly their stem cells. We know that it could be a universal aging mechanism present throughout the animal kingdom.Humans contain some versions and some variants which are more common in people who live more than 100 years. Scientists found that the three share a common protein, FoxO, which would be key against aging."If you turn the FoxO gene, the hydra age ," said scientists.
- The mollusk Ming: it is the oldest solitary animal ever discovered .It had 507 offshore years when a group of biologists pulled from the waters off the coast of Iceland in 2006 .Although it was killed , Ming might have been biologically immortal .In many animal cells , molecules that contain oxygen react with the membranes , generating small molecules that in turn damage other parts of the cells. However, a 2012 study found that ocean clams cells have membranes that are unusually resistant to such damage .
- American lobster: biological immortality can occur even in animals that reproduce sexually.The American lobster is an example. It maintains an impressive ability to regenerate even in old age. That may explain why some large specimens are at least 140 years. Their longevity may be connected to the behavior of their DNA.Long chromosomes in the cells of animals have special endings on its ends called telomeres, which help to protect DNA. However, when cells divide and reproduce chromosomes, telomeres are shortened a bit because the division does not reach the tip of the chromosome. "Shorter telomeres, shorter life". However, American lobsters use an enzyme called telomerase that lengthens.A 1998 a study revealed that it is in all its body, which presumably helps keep cells looking younger longer.
- Ancient trees: a good example is the long-lived pine . Some of these American trees began to grow 5000 years ago, in the days of the founding of the real city of Troy."They're pretty bludgeoned, they are struck by lightning, buried by snow, their branches are broken."However, a closer look at them reveals another story.A study published in 2001 compared the pollen and seeds of pine trees of different ages lived and found no significant difference in their mutation rates.In addition, the vascular tissue works as well in older trees. At the cellular level they seemed as young as when Troy was founded. Their tissues do not appear to wilt. Nobody knows how the pine does; but scientists think it is probably due to a special property of "meristems" trees.These are areas of the roots and stems that host populations of stem cells that generate new growth. Apparently, these stem cells can stay young and vigorous for thousands of years.