When Charles Darwin first saw the Galapagos Islands he was not impressed – he said that “nothing could be less inviting than the first appearance”. But later he recognised the unique nature of these islands, which he called “a little world within itself”. They set him thinking about how animals change and ultimately inspired his theory of evolution. Sarah Darwin follows in the footsteps of her great, great grandfather in this “little world within itself” to see how the Galapagos islands themselves have evolved and changed since he visited in 1835