Why are ancient African civilizations important?

Why are ancient European civilization important? If we are to measure the importance of civilizations, we must ask how we are measuring it. African civilizations are important in many ways that you may not know about. For example the Nubian culture made great contributions through their trade in many natural resources but most importantly in cattle. Nubia was part of the "agricultural revolution" that saw man using animal husbandry and farming instead of the hunter/gatherer society. Egypt gave us the clock, the calender, paper, use of text, the concept of an afterlife, the obelisk, columns, and the zodiac. Egyptian culture was the major force in influencing the ancient Greek culture, as well. For more information, I would also recommend reading about the Kush, the sub-Saharan iron age civilizations, and how important the African civilizations were to trade for European and Middle Eastern civilizations.