In 1542, the Spanish conquistador Francisco de Orellana led an expedition into the heart of the Amazon jungle. The Spanish were looking for El Dorado, the mythic civilization possessing indescribable treasures in the form of gold and silver that the Indians claimed existed within the dense forest (THE SECRET OF EL DORADO, 2006). When the conquistador Fernando Orellana returned from his travels in the Amazon, he described a scene that sounds to us today like the product of a crazed mind. Hundreds of Indians observed his passage as he sailed down the Negro River in search of El Dorado. He claimed to have come across a city stretching for 15 miles, which seems to be a description from an unbalanced mind, given that the characteristics and technology existing in the region at the time would hardly have enabled such advanced development. Orellana even claimed to have noted the existence of roads, of a network of cultivated areas, and even of walled cities. When the Spanish returned to the place some years later, they found nothing of what had been described by Orellana (PETERSEN, 2002). Well-known scientists, like Betty Meggers, had always been skeptical about the possibility of a populated Amazon, because for it to exist would require the large-scale production of food, which seemed impossible in the acid soil of the region. Without the production of a substantial food surplus, no great civilization could prosper. Betty Meggers supported her theories with the work she did in the 1950's on the Island of Marajó. The researcher discounted the possibility of advanced societies existing in the region, based principally on the poor quality of the Amazon soil. Strengthening ecological determinism, Meggers' followers suggested that the lack of favorable environmental conditions made permanent settlements impossible. (ERICKSON, p. 457; MYERS, DENEVAN, et al, 2003; MEGGERS, 1954). We Brazilians have our reasons for being skeptical about ecological determinism. As an example, the outstanding success of soybean crops in our country demonstrates that negative characteristics of the soil are not necessarily an obstacle to the development of agriculture in a particular region. Although the success of soybeans has been largely attributed to EMBRAPA, which developed a variety of the plant for the acid soils of the Amazon region, another factor may explain the possible existence of developed areas in the Amazon: black earth
