History & Future

Formation of the Amazon Rainforest

How did the Amazon Rainforest Form?

Originally the Amazon River flowed westward. Approxiamtely 15 million years ago the Andes rose as a result of the south American plate and the Nazca plate colliding. As the Andes became established, and the Brazilian and Guyana bedrock shields came together, it blocked the river causing hte Amazon to become a large inland sea. This sea eventually formed into a swampy freshwater lake where the inhabitants adapted to the new freshwater conditions. Then, around 10 million years ago, the Amazon began to flow eastward from water working into the sandstone of the Amazon, and the Amazon Rainforest was officially created. Then during the Ice Age, sea levels decreased, the Amazon lake drained, and then became the Amazon River.

Animals and the Amazon Rainforest

Approxiamtely three million years after the Ice Age, the ocean level decreased, exposing the Central American isthmus.So, what did this do?This allowed a huge number of species to migrate between the Americas. Because the Ice Age occured, the tropical rainforests then began to decrease and some parts became patches of savanna. This allowed for a different set of species to exist and allowed for genetic differentiation to occur. Once the Ice Age ended, the forest was joined once again, and a significant number of new species had rose which would add to the valuable diversity of the region as discussed on the home page.

People and the Amazon Rainforest

The Amazon has been a home to civilization before Columbus. These early societies would use mud and soil to create potter, use agricultural techniques to harvest food, and took care of the forests to optimize their resources and useful species. Much of the indigenous people would carefully mange the forest and its biodiversity, acknowledging the symbiotic relationship people could have with their environment around them. Many of the populations would often be found along whitewater rivers and used them to fish, act as a way of transportation, and used the fertile floodplain soils for agriculture.

Then, once the Europeans began to make their presence, the Ameridian population would reduce by approximately 90%. This is because much of the Europeans would fight with the Ameridian population or push them to the interior of the forest. Eventually groups from Pizarro's conquest of the INca Empire until around the begining of WWI, the Spanish and Portuguese began to take control and abuse the native population.