When Jonathan was born, Charles Darwin was only 23 years old. This giant tortoise of the Aldabra species is the longest-living (terrestrial) animal in the world known to date. It is 194 years old and still today it walks, at a very slow pace, through the gardens of Plantation House, which is the residence of the governor of Saint Helena, one of the Seychelles islands. It has lost its sight and sense of smell, and it must be fed (basically lettuce and carrots), but it is still active and weighs about 180 kilograms. Now, scientists have studied its DNA to try to extract data that will help us live longer.