"Continental drift" hypothesis that states that the continents were once one large mass that broke apart.
The continental drift hypothesis was created in the early piece of the twentieth century, for the most part by Alfred Wegener. Wegener said that mainlands move around on Earth's surface and that they were once consolidated as a solitary supercontinent. While Wegener was alive, researchers did not trust that the mainlands could move.
Answer:ccording to Arab oral tradition, Islam first came to Africa with Muslim refugees fleeing persecution in the Arab peninsula. This was followed by a military invasion, some seven years after the death of the prophet Mohammed in 639, under the command of the Muslim Arab General, Amr ibn al-Asi. It quickly spread West from Alexandria in North Africa (the Maghreb), reducing the Christians to pockets in Egypt, Nubia and Ethiopia.Islam came to root along the East African coast some time in the 8th century, as part of a continuing dialogue between the people on the East coast and traders from the Persian Gulf and Oman. Like early Christianity, Islam was monotheistic, that is, Muslims worship only one God.Islam was a modernising influence, imposing a consistent order among different societies, strengthening powers of government and breaking down ethnic loyalties.Unlike Christianity, Islam tolerated traditional values, allowing a man to have more than one wife. For many, this made conversion to Islam easier and less upsetting than conversion to Christianity.In the early centuries of its existence, Islam in Africa had a dynamic and turbulent history, with reforming movements and dynasties clashing and succeeding each other. Gaining power depended on securing trade routes into gold-producing areas in Sub-Saharan Africa. Islamic rulers expanded north as well as south. In the last quarter of the 11th century, Islam dominated the Mediterranean world.In the 14th century the Black Death came from Europe and seriously undermined the social and economic life of North Africa, or the Maghreb, as it is known. However Islam remained the dominant religion.From the 16th to the 19th century, much of the Maghreb was under Ottoman rule. By the 1880's, Islam had taken root in one third of the continent.All dates are given according to the western calendar but can be converted online.
Explanation: have fun
Overgrazing, overcropping, deforestation
