What was the chief reason for migration of peoples in North Africa to go east and south to resettle?

Question

​What was the chief reason for migration of peoples in North Africa to go east and south to resettle?

Quizplus · Accepted Answer

The drying up of the Saharan grasslands, which began around 2000 BCE, led to a decrease in resources and forced many people to migrate east and south in search of better living conditions. This led to the development of new trade networks and the rise of civilizations in areas such as Nubia and Ethiopia. Other options listed such as invasion by Egyptians or warfare among tribes may have contributed to migration in some cases, but they were not the chief reason for the overall trend of migration from North Africa. Egypt did not invade North Africa, and there is no evidence to suggest that warfare among tribes was the primary cause of migration. Egyptians also did not dam the Nile river in a way that made settled agriculture impossible, as the Nile has been an integral part of Egyptian agriculture for thousands of years. Trade connections with the Indian ocean network may have been a factor in migration to certain areas, but it was not the primary reason for the mass movement of peoples.

​What Was the Chief Reason for Migration of Peoples in North

What Was the Chief Reason for Migration of Peoples in North