How did Latin American demography and environment change from the classical age through the Spanish and Portuguese colonization?
In general, colonization caused the creation of a racial hierarchy in the Spanish and Portuguese colonies. Rank in this hierarchy was based primarily on how much European blood one had and how related one was to the European colonizers. Furthermore, European colonization caused the death of many natives who succumbed either to warfare and/or diseases; this led to a reduction in the number of natives in the colonies and to a decrease of social and political power for many natives.
European importation of slaves from Africa and other locations also led to Africans and those of African descent becoming a demographic group in Latin America. Lastly, and most obviously, European colonization led to white Europeans also becoming a demographic group in Latin America.