Why did the Amazon river reverse the direction of its flow in the last 200 million yeas?

1.Why did the Amazon river reverse the direction of its flow in the last 200 million yeas? why do the oil formations of Brazil duplicate similar ones in Nigeria? what past geological forces led to the formation of oil and natural gas deposits in the eastem foothills/valleys of the andes near the edge of the amazon basin?
2.what cultural trails did the colonizing countries of Spain and Portugal leave behind americas? how did that shape latin american countries? explain the difference with England in particular as far as cultural influence since 1492 ?
3. explain the process of how mountains cause a rain-shadow effect, and how this impact Mexico and the Andes. Describe the effect of rain shadow on vegetation and farming.
4. Describe the pre-Columbian Native Americans of Mexico/Central-America. why was Cortes able to conquer them so quickly? what farming innovations did the Native Americans of Mexico/Central and south America give to the moderm world?Discuss the Columbian Exchange.
5. How did the long rule of President Diaz help cause the Mexico Revolution and te subsequent constitution? why were people in Mexico so reluctant to trust American and European companies? Are things better today?