Darwin's big mistake

It must have been agony for the young scientist. After five years of arduous seafaring, generating one of the great natural collections, Darwin realised his notes from the Galapagos were missing a rather important fact: the locations of some of his most important samples. As a diligent naturalist, he had collected even the seemingly duller, less remarkable birds, including various finches - but he had not recorded what islands he had found them on. An expert later identified the finches as belonging to no fewer than 13 different species, with different beaks suited to different ecological niches, but Darwin had to admit that "unfortunately most of the specimens of the finch tribe were mingled together". Sadly the 40-odd adult tortoises brought on board were no use either; they were eaten, and their shells, further evidence of the emergence of separate species, were thrown away. Luckily, Darwin had enough other clues to develop his theory of evolution.