A photo from open sources
Constantly dreaming of immortality, man, however, has long been resigned to the idea of the inevitability of death and perceives it as the tragic but natural end of life. Along the way he consoles himself with the thought that nothing on Earth lives forever. And here not! There are living organisms on our planet whose lifespan is not limited. In ancient Greece, in ancient Rome the average life expectancy did not exceed 30 years. In the 18th century in Europe rarely anyone lived to 40. By the beginning of the 20th century, the average a man beat off death another 10 years of his life. Why did people live so short? Mankind has mowed up wars and even more numerous diseases and epidemics. Thanks to medicine, we forgot about many diseases. Who scares smallpox, cholera, typhoid now? The scourge of God has become something like scary tales. Modern European man lives about 70 years, and the main cause of death was “irreversible age changes in the body, “ie old age. But is aging really organism programmed initially? In bottom sediments oceans in the soils of Northeast Siberia, scientists find living bacteria, estimated at several thousand years old! By our standards, this is practically immortality. But if immortal unicellular living organisms, possibly among living things with more complex structure there are such centenarians? Yes, such there is. Scientists have long coined the term “biological immortality “and among the diverse animal world found unique specimens that do not age. Officially science recognized immortal: freshwater hydra (class aquatic invertebrates), jellyfish Turritopsis nutricula, Antarctic sponge Scolymastra joubini, freshwater pearl (bivalve mollusk Margaritifera). These creatures die from hunger, disease, become victims of predators, but their body is not subject to senile changes. 
Photos from open sources
Aleutian sea bass does not age (the control specimen lives 200 years old and not going to die), coral salmon, giant grouper (perch family), North Atlantic lobster. “Under suspicion “pike, sturgeon and beluga more familiar to us. It is noteworthy that their growth throughout life does not stop, it and becomes the cause of their death. Food a grown giant needs more and more, hide from the enemy or for hunting getting harder. With increasing body weight, speed decreases movement (do not keep up with prey, nor from a pursuing predator come off). In the end, these immortals also perish, but from external causes, full of strength and health.
A photo from open sources 
Photos from open sources
Potentially immortal are a painted turtle, Box Carolina Turtle and Blanding Turtle, also dying because they “grow” out of their ecological niche. 
Photos from open sources
Of course, there is a huge distance between a person and a turtle size, but their example gives us hope that humanity someday he will find the aging gene and learn to turn it off. Let be not even forever. Just imagine: 50 years – youth, 100 – maturity and another 50 – slow withering. Yes it’s almost eternity!
A life
