Gladyshev has also studied Brandt’s bat – a tiny creature that lives for more than 40 years, despite weighing little more than a sugar cube. “Considering the size, it’s the most extreme case,” says Gladyshev. He has found unusual mutations around its receptors for growth hormone and insulin-like growth factor – alterations that could offer further clues about ways to control metabolism in mammals, limiting the damage that normally comes with age.

Would the record-breaking bowhead whale reveal similar insights? The whale’s enormous size – 20 metres long and up to 100 tonnes in weight – creates some unique challenges that are of particular interest to biologists like de Magalhaes and Gladyshev. For instance, if its cells burnt energy at the same rate as mice cells, the excess heat would boil the surrounding water, so it has evolved to live with a slower metabolism and lower body temperature.

Such a huge body also puts you at enormous risk of cancer, thanks to simple mathematics: the more cells you have, the more likely you are to develop a harmful mutation. (Indeed, one study found that taller people are slightly more likely to develop cancer than shorter people, for this very reason.) And the problems become even greater the longer your life span. “When you live longer, you go through more divisions, so the likelihood of cancer increases hugely,” says Leonard Nunney at the University of California, Riverside, who researches the evolution of cancer.

Based on human rates of cancer, all large whales should all be riddled with tumours before they have even grown up – yet they continue to live for at least another century. This fact is known as “Peto’s Paradox”, and it suggests that the whales, like the naked mole rat, have some clever evolutionary tricks to deal with harmful mutations. “When put in the context of other animals, they really are outliers,” says de Magalhaes. “They must have tumour-suppressing mechanisms that we lack.”