the western part once turned into a huge wetland, after the Andes emerged from the ocean. that was more than 10 Ma ago although. that was also what made the wes

the western part once turned into a huge wetland, after the Andes emerged from the ocean. that was more than 10 Ma ago although. that was also what made the western Amazonia part differ on its biodivesity humans may altered the biodiversity of Amazonia by breeding only wanted species. but we don't have too much evidence of that (yet). but if it was, the biodiversity of pre-humans was probably richer, as indigenous apparently managed the forests with fire and farmed hyperdominant cultures [0] [0] https://portal.amelica.org/ameli/journal/181/1813954027/html/ https://portal.amelica.org/ameli/journal/181/1813954027/html...