How did the introduction of Islam affect the development of African civilizations?

Islam in Africa has linked together diverse peoples through better cultural understanding and a spirit of cooperation and common weal. ... The historial impact of Islam upon trade, particularly in West Africa, greatly increased the wealth of African people and helped form many great African empires.

It's either

Islam in Africa has linked together diverse peoples through better cultural understanding and a spirit of cooperation and common weal. ... The historial impact of Islam upon trade, particularly in West Africa, greatly increased the wealth of African people and helped form many great African empires.

OR

ECONOMIC EFFECTS

Islam promoted trade between West Africa and the Mediterranean. The religion developed and widened the trans-Saharan Caravan trade. The trade enriched the West African and the Muslim traders. Muslims from North Africa came in their numbers and settled in the commercial centres.

people can eat food during that time