Introduction : defining nature -- What is a species? -- The history of life -- How many species are there? -- Measuring diversity -- Niches -- Patterns in species richness -- Drivers of diversity -- Does diversity matter? -- Organisation at the community scale -- Stability -- Changes through time -- Changes through space -- Global patterns of life -- Regional species richness -- Latitudinal gradients -- Earth history -- Dispersal -- Life on islands -- Reinventing islands -- What is a natural system?.