Some animals live a very fast, dangerous, exciting life and put a lot of time and effort into having lots of offspring while still young; others, such as tortoises, have a much slower pace of life and use their resources to live longer. In comparison, they have much slower biological activities than a lot of other animals. Some believe that having a lower metabolic rate combined with an almost complete ‘switching off’ during dormant periods of hibernation and estivation plays a significant role in their living a long life.
Tortoises are equipped with adaptations allowing for their protection from predators. Once they reach a certain growth threshold, their shell gives them a fair amount of protection. Hence, their predators are few; perhaps man being one of their most feared (certainly in the past). Living on an island where there is plenty of vegetation and where you’d be hard-pressed to find any other animal larger than yourself would also mean that you can be free to roam without fear of attack.
Another biological feature that some feel may contribute to tortoise longevity is their very long telomeres – the protein caps at the ends of chromosomes. The theory is that telomeres shorten each time cells replicate (which can be shown in laboratory conditions) eventually becoming so stubby that they lead to the death of that cell. In this way, the telomeres act as an initial signal of cell health.
The official Guinness World Record holder for the longest living animal is Tu’i Malila, a radiated tortoise from Tonga who died aged 188. There are other unconfirmed contenders however, including Adwaita, an Aldabra giant tortoise from a zoo in India, believed to have been 255 when he died in 2006.