L'aridification du Sahara : quel rôle dans l'éclosion de la civilisation égyptienne ?

The presence of man in the Western Sahara, a vast territory which is a desert today, was made possible thanks to the favourable climatic conditions between 10000 and 8000 BP (about 10000 and 7500 cal BC) then from 7000 BP (6000/5900 cal BC) until the beginning of its permanent aridity at around 4500 BP (about 3300 cal BC). The coming and going between the Sahara and the Nile Valley was discovered as far back as the 1960s owing to studies of rock carvings (by J. Leclant and P. Huard). Thereafter the question of the origin of Egyptian civilization appeared in a completely new light with the possible influence of populations located in the western desert. Extensive research concerning large territories has been carried out for the past twenty years by American and German teams (F. Wendorf, F. Hassan, R. Kuper, S. Kröpelin) with a palaeo-environmental approach and has uncovered decisive new data. The early presence at the western limits of Egypt of human groups who may have raised livestock and practised an early form of agriculture, as well as their withdrawal to more ecologically favourable areas at the end of the humid Neolithic period during the 5 ^th millennium before our era, cast a new light on the development of the first Neolithic and Predynastic cultures of the Nile Valley. During the 5^th millennium, while the first known domesticated species in the Nile Valley and Faiyum are clearly of eastern origin (sheep, goats, pigs, wheat and barley), the question of exchanges between the Saharan and Nile areas remains concerning earlier periods as well as the real impact of the increasing aridity on the Sahara in the birth of Egyptian civilization.