The effect of recent radiocarbon dates from North Africa has largely been to extend the principal phases of prehistory back in time. The Middle Palaeolithic now seems to be essentially beyond the range of the radiocarbon technique, at least in the Eastern part of North Africa, although it may persist later in the West, and, throughout North Africa (with the sole exception of Cyrenaican Libya), there remains a disturbing hiatus between the Middle Palaeolithic and the subsequent Late Palaeolithic bladelet industries. The latter now seem to appear at about 20,000 B.c. over most of non-Saharan, North Africa, and may eventually be found to be earlier. Some of the earliest such occurrences may well be associated with domestication of plants (in Egypt) and of animals (in Algeria). If so, this will necessitate serious reconsideration of our concepts of the ‘Neolithic’. In any case, a true Neolithic appears in parts of the Southern Sahara as early as the eighth millennium B.C., and is widespread in the area by the seventh millennium. Curiously, the beginnings of the Neolithic are much later in the neighbouring and more luxuriant areas (the Nile Valley, the Mediterranean littoral and the Maghreb) than they are in the desert. Less research has been done on the final prehistoric and early historic periods, but, in the North, the invention of the Libyan alphabet and, in the South, the later Iron Age of Chad both seem earlier than had been thought.
EVOLUTION OF PREHISTORIC FISHING IN THE NILE VALLEY