How did the conflicts between Iberian and American civilizations forge connections that changed them all

The conflicts between Iberian and American civilizations resulted in a solid Iberian victory, because both Portugal and Spain became the political authorities in the region, replacing the old indigenous political rule.

However, these conflicts also forged a new kind of civilization, ruled by Iberians, but mostly populated by people of mixed iberian-american ancestry. The cultural diffusion and mixture was very strong, and this is why today countries like Brazil, Mexico, or Colombia, are considered to be mestizo or mixed countries.