Complex sentence: Cultivated peanuts are native to the eastern foothills of the Bolivian Andes and were mashed to become a pasty substance by the Incas almost 3000 years ago, although they combined it with cocoa and it was not as smooth as modern peanut butter.
Split into simpler sentences: Cultivated peanuts are native to the eastern foothills of the Bolivian Andes. They were mashed to become a pasty substance by the Incas almost 3000 years ago, although they combined it with cocoa and it was not as smooth as modern peanut butter.