In this two-part program, we will showcase some of the species that live the longest. They are blessed with what is called “biological immortality.” We lobsters are one of those species! Researchers believe that the secret our longevity is an enzyme called telomerase. It protects the ends of chromosomes from shortening and losing some Deoxyribonucleic acid (DNA) when cells divide. Another species that exhibits “biological immortality” is the naked mole rat. Aside from their defenses against cancer, naked mole rats have two ways to keep their bodies young. Number one, they can withstand high amounts of oxidative stress. Number two, they have high levels of chaperone proteins that stabilize the correct folding of other proteins. As far as we know, Greenland sharks have the longest lifespan of any vertebrate species on the planet. One possible explanation is their extremely slow metabolic rate. Giant tortoises are world-renowned for their long lives. The scientists noted that compared to the mammals, the tortoises had more immune system-protecting gene copies - 12 to be exact, while the mammals only had one. These genes assist the body in neutralizing infections.