1. what factors led to the downfall of the empires of ghana, mali, and songhai? 2. compare the economic, political, and social developments in east, west, and south africa. 3. how did the legacies of the olmec, zapotec, and chavin cultures impact mesoamerican and south american civilizations? 4. describe the roles of people in the maya, inca, and aztec societies. 5. compare the key economic, cultural, and political characteristics of the major civilizations of meso and south america. 6. what was the impact of the significant meso and south american rulers? 7. what were the effects of transportation, trade, communication, science, and technology on the preservation and diffusion of culture? 8. what was the impact of the columbian exchange on europe, africa, asia, and the americas?