At about 194, Jonathan the tortoise is teaching scientists about longevity

Jonathan, an Aldabra giant tortoise living on the island of St Helena, is about 194 years old — the oldest-known land animal on Earth. Scientists have now sequenced his genome, and a study in the journal Science Advances found his DNA carries variants linked to longevity: DNA repair, tumor suppression, and extra copies of a gene that hunts down ageing and cancerous cells. Brought to the island in 1882, Jonathan is mostly blind from cataracts these days — but his veterinarian calls him a ‘gentle giant’ with a voracious appetite, who lifts his long neck whenever he hears his name.