Scientists may have discovered how the Greenland shark lives up to 400 years. A new study on bioRxiv reveals that the shark’s DNA holds the key. The Greenland shark has a massive genome of about 6.5 billion DNA base pairs, twice that of humans, with many repeating genes known as transposable elements. These elements can cause mutations but also contribute to the shark’s ability to repair its DNA, which scientists believe is crucial for its exceptional lifespan.