When fossils of a diminutive, recently extinct race of humans were discovered in a cave on Flores, one of the most easterly islands of the Indonesian archipelago, researchers can be forgiven for assuming they were down-sized by the peculiar selection pressures that act upon insular species. On Flores, natural selection has morphed several familiar species to unfamiliar sizes. There be dragons: three metre, 200kg monitor lizards, also known as the Komodo dragon, plus the fossilised remains of an extinct giant rodent, Spelaeomys, and extinct Stegodon pigmy elephants. The tiny skulls of the Flores fossils ignited a heated, sometimes ad hominin,...