In 1972, UNESCO established the World Heritage Convention to recognise places of natural and cultural significance around the world. In 1978, they announced the first twelve sites and the Galapagos Islands of Ecuador were top of the list. In a lunchtime talk to year 7 scholars, biology teacher Dr Henry Nicholls introduced the students to this archipelago, celebrated for its natural heritage, though it has now acquired huge cultural significance too through its association with Charles Darwin and the idea of evolution by natural selection.

The students learnt about the underlying geology of the islands and about its most striking residents, the giant tortoises. Genetic analysis suggests that the first giant tortoises to reach the Galapagos were probably did so a few million years ago, floating out from the South American mainland into the Pacific, some washing up on one of the Galapagos islands. In the intervening eons, the descendants of these colonising reptiles managed to find their way to different islands and under the different local conditions of each volcano diverged into at least 15 different species.

Over the course of the 18th and 19th centuries, however, whalers and pirates with a taste for fresh meat decimated the populations on several islands. Dr Nicholls told the story of Lonesome George. By the time he was found on the northerly island of Pinta in 1972, he was the only surviving member of his species and lived for the next 40 years in captivity on the central island of Santa Cruz. When George finally died in 2012, the Pinta tortoise vanished forever.

This sadness was partially mitigated by the news that Mr Cavendish has tortoises…not giant ones of course but still of much interest.