The population of the native american tribes decreased dramatically due to

The population of the Native American tribes decreased automatically due to disease. This was not the only reason, however. The population also decreased due to European colonization and contact with them in general (lots of times, Europeans would kill/murder Indigenous peoples).

Explanation:

I'm not sure if your class (or whatever this question is from) has a specific book or text that you're reading (or if this question is multiple choice) so I answered it to the best of my ability with the things I've read, learned, and researched. Hope this helps though!!

the correct answer is history and tradition.