Answer:
Grabbing Brazil as an example, we can understand the colonization by Europeans as a decisive factor for the difficulties suffered by Brazilian Indians to keep their culture to this day.
Culturally, americans brought many different objects that Indians have never saw. For example, they brought big clothes when indians were used to walk naked in many places due to the high temperature in Brazil. Europeans found it to be offensive, obligating the Indians to dress up. They also brought a different language, Portuguese, and made the Indians learn so they could communicate, instead of learning the Indians traditional language. They also imposed their religions, the Catolicism.
Economically, the Indians in Brazil were used to hunting small animals, fishing and collecting fruits and vegetables that they found on nature. Portuguese came with the idea of planting to sell to other countries, destroying and ending some of the originary species that were there. Due to this highly predatory exploitation of some plants, like the Pau-Brazil (that gave the name of the country), they destroyed entire forests, such as the Atlantic Forest, that has only 7% of its original size today.
