Question: where did the earliest civilizations emerge why there

title: Cradle of civilization
text: The developed Neolithic cultures belonging to the phases Pre-Pottery Neolithic A ( 10,200 BC ) and Pre-Pottery Neolithic B ( 7600 to 6000 BC ) appeared in the fertile crescent and from there spread eastwards and westwards . Contemporaneously , a grain - grinding culture using the earliest type of sickle blades had replaced the culture of hunters , fishers , and gathering people using stone tools along the Nile . Geological evidence and computer climate modeling studies also suggest that natural climate changes around 8000 BC began to desiccate the extensive pastoral lands of northern Africa , eventually forming the Sahara . Continued desiccation forced the early ancestors of the Egyptians to settle around the Nile more permanently and to adopt a more sedentary lifestyle . By about 5500 BC , small tribes living in the Nile valley had developed into a series of inter-related cultures as far south as Sudan , demonstrating firm control of agriculture and animal husbandry , and identifiable by their pottery and personal items , such as combs , bracelets , and beads . The largest of these early cultures in upper ( Southern ) Egypt was the Badari , which probably originated in the Western Desert ; it was known for its high quality ceramics , stone tools , and use of copper . The oldest known domesticated bovine in Africa are from Fayum dating to around 4400 BC . The Badari cultures was followed by the Naqada culture , which brought a number of technological improvements . As early as the first Naqada Period , Amratia , Egyptians imported obsidian from Ethiopia , used to shape blades and other objects from flakes . By 3300 BC , just before the first Egyptian dynasty , Egypt was divided into two kingdoms , known as Upper Egypt to the south , and Lower Egypt to the north .