They invaded the land of the native americans, treating them in an unfriendly and violent manner when they arrived. The effects of colonization on the native populations in the New World were mistreatment of the natives, harsh labor for them, and new ideas about religion for the spaniards.
This would be an answer
But I don't know exactly what your answer choices are.
oil spills non native species
It was caused due to political conflict such as social inequality, tax burden, the rise of the bourgeoisie and financial crisis.