Reliable knowledge of early civilizations of the Americas is (36) to archeological records, since so much of the (37) culture was destroyed by early (38) . Nevertheless, evidence of impressive achievements in monumental (39) as well as in the art of healing, (40) , mathematics, and engineering has been (41) that commands respect as well as (42) for the loss of this knowledge. In the field of agriculture, these civilizations left a (43) that has greatly enriched the food of today’s planet. White potatoes, corn, beans, tomatoes, squash, chocolate, tapioca, vanilla, and turkey are just (44) Lost, however, are the secrets of the Mayan astronomers and the Inca builders as well as many medicinal practices. Perhaps the greatest casualty, however, (45) . Indians in these civilizations seldom warred with nature; instead, they adapted to it. Our present concern with ecology causes us to (46) .