Brazil is the largest country in South America, covering an area of 8.5 million square kilometers and with a population of approximately 170 million people, according to the 2000 census. Brazil encompasses several distinct biomes, notably some 4 million square kilometers of the Amazon basin, as well as the Atlantic forest (which once covered some 1.4 million square kilometers) and the Pantanal, the world's largest interior wetland (110,000 square kilometers).

Human occupation in what is now Brazil appears to have begun at least 11,500 years ago, based on pottery shards found in the Amazon. Estimates of the indigenous population of Brazil upon European contact in 1500 have ranged widely, and recent estimates have been higher, up to 5 million. The higher estimates are based on growing ...