Compared to the diversity of life found on the mainland, few species have managed to make the 960-kilometre journey to the Galápagos. But it's the islands' small number of species in isolation that has fascinated generations of scientists. Like a self-contained puzzle, life on the Galápagos can be unravelled in a way impossible for the tangled mass of mainland biological relationships. And, as Darwin found, the lessons learnt from the Galápagos microcosm can have implications for the rest of the planet.