Amazonia is the world's most diverse wilderness area. Encompassing more than 6 million square kilometres in nine countries of northern South America, its biodiversity, in the full meaning of the word, is impressive. Tropical landscapes range from savannas, to forests seasonally and even permanently flooded by the largest rivers in the world, to white-sand forest and scrub, and terra firme forests (Prance 1987). More than one tenth of the world's species occur there (Prance & Lovejoy 1985), with all the untapped genetic resources, increasingly recognised, and exploited, as an essential for our future.
Recent compilations indicate at least 40 000 plant species, 427 mammals, 1294 birds, 378 reptiles, 427 amphibians and around 3000 fishes (Mittermeier et al. 2002). The conservation of Amazonia is a global challenge, given its biodiversity, besides its importance in the regulation of regional hydrological regimes and climate and terrestrial carbon storage (Fearnside 1997, 1999, 2000; Saint-Paul et al. 1999).
A biome-level conservation system for the Amazon requires a good understanding not only of the major biodiversity patterns within the region but also of the relative importance of the evolutionary and ecological processes responsible for their generation and maintenance. In this chapter, we explore these issues; we use primates as a study group and hence update the insights provided by Alfred Russel Wallace (1852) in his remarkable account of primate biogeography in Amazonia. First, we describe the areas of endemism currently recognised for vertebrates in the region.