Tortoise and turtles live longer than most other animal. If you were a tortoise, you might live for more than 150 years. Donna Holmes said that One giant Glapagoes tortoise named Harriet even live to be more than 170 years old. Holmes explained that biologists have come up with several ideas, or theories, for how turtles can live for so long. One theory has to do with the fact that turtles are cold-blooded and have and scientists call it is slow metabolism. They don’t have to eat as much food to survive, since they use energy they get from food very, very slowly. Since they are cold-blooded, they also don’t need to use a lot of energy to keep themselves warm.
In life, Lonesome George was arguably the most famous tortoise in the world for being the last of his species. Now, over half a decade after he died, he's still making headlines by helping geneticists understand why giant tortoises have such long lifespans.
George lived on the Galapagos islands, which inspired Charles Darwin's theory of natural selection.
He died in 2012, at the age of around 100 years old, according to scientists' estimates, the BBC reported. He was the last of the Chelonoidis abingdonii, or Pinta, tortoises who are said to live up to 200.
Scientists believe the life-spans of giant tortoises like George are so long because they have gene variants that tweak how their DNA is repaired and their bodies respond to inflammation and the development of cancer.
Tortoises have very slow metabolisms, which means they burn energy at a slower rate than smaller and faster animals. In 1908, physiologist Max Rubner introduced the rate of living theory, which suggested an inverse correlation between metabolism and lifespan (the faster the metabolism, the shorter the life). Scientists have had some issues with the theory over the past century (some argue that metabolism is a “poor measure of energy expenditure”), and it has largely been discredited, but it did spawn the phrase “Live fast, die young,” and it serves as the basis for expanded research on the topic.
The link between metabolism and longevity is still not understood, but some scientists believe that metabolism is linked to the creation of free radicals, unstable molecules that damage cells and that increase as more energy is burned by the body. According to this theory, tortoises live longer because their slow metabolisms burn less energy, which means less harm to the cells in their bodies.
Theories on aging alone don’t fully explain how tortoises live much longer than humans, but their reproductive lives and size may hint toward an explanation. Because of their built-in home security system (the massive hard shells) and their geographic isolation (they only live on a few specific islands), giant tortoises have very few predators to worry about. Besides simply not becoming prey, this means that giant tortoises don’t have to rush into reproduction to keep their species alive. The tortoises essentially reserve their biological resources to keep themselves alive—they needn't rely on them to aid procreation while they’re young.
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