Agriculture is essentially a process of manipulating the distribution and growth of plants so that greater quantities of their edible parts are available for harvesting and consumption. The world’s earliest-known evidence of natural resources having been manipulated in this way comes from archaeological excavations at the Klasies River cave site in South Africa, where conspicuous deposits of carbonized material have been identified as the inedible residues of geophytes (buried plant foods, such as tubers, roots and corms) that are a feature of the region’s long-established vegetation.1
The carbonized deposits at Klasies River cover a significant period of time around 70,000 years ago, and are absent on levels dating from before and after that period; the argument for their representing the earliest-known evidence of people having managed a natural resource rests upon the fact that the geophytes are perennial plants growing in extremely poor soils. A large proportion of their nutritious biomass is concentrated underground, but the resource is renewed very slowly under natural conditions, and exploitation on the scale evident at Klasies River could only have been sustained by some form of management, such as controlled burning of the surface vegetation.
The soils of the region are poor, but its mature vegetation nonetheless covers the ground with a dense profusion of long-lived plant species; seed is set annually, but germinates only when and where there is room. Burning clears the ground and causes hard seed-cases to burst, thus promoting the germination of seed that might otherwise have lain dormant for decades, and plant cover regenerates.
The fynbos, whose name is derived from the Afrikaans for ‘fine bush’, is the richest, most varied, and concentrated area of vegetation on Earth. Covering just over 91,000 km2 of the coast and hinterland to the north and east of Cape Town, it supports over 8,600 plant species, nearly 5,800 of which are found nowhere else. By comparison, the land area of the British Isles is three and a half times larger but has only 1,500 plant species in all, fewer than twenty of which are endemic. In fact, the Fynbos Biome (or the Cape Floral Kingdom as it is also known) is so distinctive that it has been named as one of the world’s six botanical kingdoms. Even though so small, the Fynbos Biome is botanically on a par with the Boreal Kingdom, which covers approximately 42 per cent of the Earth’s land surface and includes almost the entire northern hemisphere – 53 million km2 in all.2
Geophytes are a characteristic feature of fynbos flora; natural fields of them are found along the Cape mountains and in acid soils at the coast. Indeed, the distribution of these resource-rich patches is said to explain the distribution of human-occupation sites, while the lack of essential trace minerals in the region’s very pure (and high pH) ground waters explains the coastal location of many sites: shellfish is thought more likely to have been a source of these essential dietary supplements than a staple resource. Hunting and scavenging provided the protein required to balance a subsistence diet high in carbohydrate.3
The exploitation of geophytes on the coastal hinterland of South Africa around 70,000 years ago is an early example of people directly manipulating their environment in order to produce more food, but it does not mark the beginning of a progression that can be traced, stage by stage, from the fynbos of the Cape Floral Kingdom to the realm of modern industrial farming. The early development of agriculture was erratic (in Africa and around the world generally); innovation occurred at various places at different times and seems to have been prompted by necessity: established practices persisted so long as they satisfied immediate needs, and change arose only when they proved inadequate.
Furthermore, there was nothing preordained about the advent and development of agricultural innovation; when it failed, or demanded more effort than the benefits justified, or simply exhausted the available resource, people reverted to the old tried and trusted practices. The Klasies River evidence is a case in point: people inhabited the site continuously for a very long time but exploited the geophyte resource intensively for only a relatively brief period. Before and after that time they pursued long-established food-gathering strategies.
The Klasies River evidence stands alone as a very early example of intensified food production, but Africa probably is littered with other examples as yet undiscovered. It would be surprising indeed if people had not occasionally manipulated the environment to their advantage in similar fashion throughout the millennia, and given the amounts of effort involved it is perhaps even more surprising that any should have adopted the strategy as a permanent way of life. Clearly, some exceptional factors must have been involved. Stress is the most likely candidate, either the stress of environmental degradation, or the stress of a population growing beyond the carrying capacity of a restricted environment. Either of these factors would impel people to intensify food production. Both were increasingly evident among the human populations of the eastern Sahara and the Nile valley from around 18,000 years ago, when the first signs of a move towards agriculture as a permanent way of life are recorded.
Though the verdant green course of the Nile appears to be the very antithesis of the bleached Saharan sands through which it flows, these two contrasting features have together constituted a primary force in the development of agriculture and settled human society in Africa. The Sahara acted as a pump, drawing people from surrounding regions into its watered environments during the good times, and driving them out again as conditions deteriorated (though not necessarily returning them to their point of origin). The Nile, for its part, was a refuge for people retreating from the desert, and then a reservoir from which the desert region was repopulated as conditions improved.
The Nile is commonly believed to have been a conduit along which the principles of food-crop cultivation had flowed into Africa along with the wheat, barley, peas, and lentils initially domesticated some 9,000 years ago in the ‘fertile crescent’ of the Near East. It is true that the ancient Egyptian civilizations founded on the Nile over 5,000 years ago were sustained by the exceptional productivity of these crops, but they were a comparatively recent introduction, arriving long after the cultivation of indigenous African plants had begun further south.
Contrary to expectations, the earliest evidence of a shift towards a critical dependence on food production as opposed to food gathering comes not from the floodplain of the Nile, but from sites in what is now the empty and waterless Sahara. The development was complex, involving the domestication of plants and livestock, technological innovation, the establishment of villages, and an increasing level of social interdependence. ‘It was undoubtedly an optimal adaptation to this specific semiarid environment.’4
The Sahara desert had been widely inhabited until the last glacial maximum, when conditions of increasing aridity drove people (and practically all animals) out of its previously productive wooded grassland and savanna environments. People moved from the desert in all directions. Essentially nomadic – though exhibiting some tendency to settle at lakesides and other sources of food and water – the groups moving to north and south continued to follow their established hunting and gathering way of life. The groups that moved east into the Nile valley, however, adopted a distinctly sedentary lifestyle. Indeed, they had no choice. The narrow strips of green floodplain flanking the Nile were bounded by waterless desert, and movement along the riverside plains was constrained by the presence of competing groups.
The Nile along which people congregated 18,000 years ago was a quite different river from that which flows through Egypt today. It was much smaller, and flowed more slowly through a tangle of braided channels across a wide elevated floodplain rather than along a single massive stream. The river carried a heavy sediment load, and the silts deposited along its length steadily raised the level of the river and its floodplain. In effect, the Nile valley at this time was an elongated oasis: a sharply defined area of inhabitable territory beyond the boundaries of which human survival was impossible. The ‘oasis’ extended all the way from the Sudan to Cairo – a distance of over 800 kilometres – but it was nowhere more than a few kilometres wide. Its food resources were varied and nutritious, though quantities and availability were always subject to seasonal variation and the vagaries of the Nile’s annual flood. During the critical two to four weeks when the flood was at its height each year, people and animals were driven out of the wadis and valley of the Nile and crowded into the narrow band of inhabitable land that lay between the flood waters and the arid desert beyond.
People hunted large mammals for meat and hides but environmental and territorial constraints meant that only small numbers of a limited range of species were available. Indeed, large mammals constitute a very small proportion of the faunal remains found at archaeological sites (only about 1 per cent in one instance) and only three species are represented: the hartebeest, the dorcas gazelle, and the aurochs – wild cattle. Coots, and migratory geese and ducks, were caught regularly, but fish was by far the most important source of protein – primarily catfish. Harpoons such as were found along with catfish remains at the Katanda site on the Upper Semliki valley in Zaire (see pages 1356) were not present at the early Nile valley sites, but the fish could easily have been speared or even caught by hand when they congregated to spawn in the shallows.
For carbohydrates, the Nile valley offered its inhabitants a considerable variety and seasonal abundance. Twentyfive different seeds, fruits, and soft vegetable tissues have been distinguished among the archaeological remains from sites at Wadi Kubbaniya, and of those identified to species the tubers of the wild nut-grass (a sedge, Cyperus rotundus) are the most prevalent. Nut-grass is abundant in the Nile valley today, growing in dense swards at the water’s edge. Its rhizomes produce small tubers which are rich in carbohydrates and fibre. The mature tubers are woody and contain a heavy dose of alkaloid toxins, but the young plants are tender and relatively toxin-free (though roasting or grinding before consumption is still advisable). Grindstones bearing traces of starchy vegetables suggest that nut-grass tubers began to constitute a major part of the staple diet at Wadi Kubbaniya from around 19,000 years ago.5 Certainly, the plant is impressively productive, capable of supplying 3.3 kg of tubers per square metre where it grows in dense swards (by comparison, modern barley achieves a maximum grain-yield of 3.5 kg per square metre), and a family armed with digging sticks could have gathered enough to meet several days’ carbohydrate requirements in a matter of hours.6 Furthermore, nut-grass thrives on exploitation. The soil disturbance resulting from the harvesting of tubers stimulates the production of yet more tubers, so that heavy annual harvesting would itself guarantee an equally heavy harvest of freshly formed tubers in the following year.
Wadi Kubbaniya provides a unique and unusually full record of how people lived in the Nile valley 19,000 years ago – 14,000 years before the pyramids were built. The seasons followed not the elevation of the sun but the rhythm of the annual flood, which started to rise in early July, reached its peak (around seven metres or more above low water) six to eight weeks later, and usually had fallen to its previous level by November. Catfish were harvested as they congregated to spawn on the rising flood, and again as they retreated with the falling waters. Both these events were of short duration, in which every able-bodied individual in the community participated. Undoubtedly, more fish were caught than could be eaten immediately, and the surplus probably was sun-dried or smoked over hearths, thus providing a supply of dried fish for lean periods ahead, though it would not have lasted more than four or five months before spoiling.
During the flood, people collected dryland produce, such as dates and acacia seeds, but as the flood waters began to recede, they began harvesting the major carbohydrate component of their diet: the roots of wetland plants, whose growth had been stimulated by several weeks of immersion. Wild nut-grass tubers were the first to be harvested, followed by club-rush tubers. These plants are so prolific that – like the catfish – they doubtless were gathered in excess of immediate needs and stored for use in time of need. Later, as the water receded further, the Kubbaniyans had access to the edible rhizomes and flower-buds of water lilies.
As the wetland plants matured during October and November, they produced edible seeds: nutlets of club-rush, nut-grass, and papyrus; grain from the wild millets, and seeds of water lilies. Waterfowl that stopped over on their southward migration would have been the target of hunters at this time of year. In January and February, the rhizomes of cat’s-tail, bulrush, papyrus, and common reed formed their starchy storage rhizomes. Some, at least, of these plants would have grown in extensive stands, and their rhizomes thus were also a resource that could be gathered for storage as well as for immediate consumption. Likewise, the fruit of the doum-palm, which was available from February through to April, was eminently storable, as were the edible seeds of acacia, which were abundantly available from March onwards. And then it was July, and time for the flood to rise again.7
Wadi Kubbaniya provides an exceptionally full insight into how a group of people lived along the banks of the Nile 18,000 years ago, but these were not the only people settled in the Nile ‘oasis’, then or later. Many more occupation sites of various ages have been discovered (and doubtless still more remain undiscovered), and though the numbers are not large, it is clear that the sites became progressively more numerous and larger with the passage of time.8
In the course of the 2,000 years immediately prior to the last glacial maximum 18,000 years ago, the number of sites in the Nile valley increased fourfold; during the following 2,000 years (18,000 to 16,000 years ago) the number almost doubled again, and it increased by yet another one-third between 16,000 and 14,000 years ago. By 12,000 years ago, the number of occupation sites along the Nile valley was more than ten times the number known from before the last glacial maximum, 6,000 years earlier.
Throughout this period the majority of sites had covered an area of about 400 m2 (the home base for a group of perhaps forty people), but the size of the largest rose from 800 m2 18,000 years ago to more than 10,000 m2 6,000 years later – large enough to constitute a village. These increases in the size and number of sites clearly denote an increase in overall population size, and since the area of the Nile ‘oasis’ would have varied little throughout the period in question, the growing numbers of people could only have been fed by increased food production.
Adaptation to the pressure of demands for more food was characterized by a more sedentary way of life and the development of food-production and storage strategies. As at Wadi Kubbaniya, people exploited the valley’s wild resources, but increasingly from semi-permanent settlements close to the floodplain and with a distinct shift to the utilization of grain as well as a greater reliance on fish and waterfowl. The adoption of this broad adaptive strategy provided the large food supply needed by a growing population, 9 but achieving maximum production called for a good deal of planning and the management of labour. This development marks the beginning of an organized food-producing system: agriculture.
Dating from more than 15,000 years ago, the evidence from the Nile Valley is arguably the earliest comprehensive instance of an organized food-producing system known anywhere on Earth. Given time, this pioneering system might have developed into the stupendous civilizations that ruled ancient Egypt for two and a half millennia from about 5,000 years ago. But it could never be. Disaster struck the Nile valley as its population reached a peak, and by 10,000 years ago occupation density had plunged to a level only slightly above that known for the time of the Wadi Kubbaniya site.
The cause of the calamity originated more than 2,000 kilometres to the south, in central Africa at the headwaters of the Nile, where the climatic amelioration which followed the last glacial maximum had brought a very marked increase in rainfall. The Nile is peculiarly dependent on conditions at its headwaters and highly sensitive to changes in them. Its route through the desert means that no water flows into it for 44 per cent of its total drainage area.10 Overwhelmingly, the Nile is fed by rain falling in its southern catchment. The Ethiopian highland provides most of the annual discharge via the Blue Nile and the Sobat; the smaller but less seasonal White Nile drains the east and central African highlands and sustains the river during the season of low flow. Changes in the amount and seasonality of either source can have a profound effect on the volume and character of the river downstream.11
Around 13,000 years ago, heavy and persistent rains which had already flooded even the desiccated Kalahari basin with a number of large lakes12 moved steadily northward. The central African lakes rose tens of metres to unprecedented levels; the previously dry Lake Victoria filled and discharged massive quantities of water into the upper Nile. The effects downstream were catastrophic.
From a sluggish river flowing through shallow braided channels, the Nile was transformed over a period of five hundred years (12,000 to 11,500 years ago) into what has been called the ‘wild’ Nile.13 Extremely high floods were only the beginning of the problem. The heavier rains falling on the upper catchment area produced more vegetation; as ground cover increased, erosion was reduced and the Nile carried less sediment. Less silt was deposited downstream and, most catastrophic of all, the lightened, faster-flowing ‘wild’ Nile began to cut a single channel through the valley.
With the Nile now flowing through a single deep channel, the extent of the floodplain was severely reduced. The quantities of available plant foods declined, and even the catfish became less plentiful with the shrinking of their spawning beds. The levels to which the human population had soared could not be sustained, and the pressure on resources mounted inexorably. Competition for food intensified, doubtless provoking conflict of which the massacre at Jebel Sahaba (see pages 142 – 4) is probably an extreme example.
The northward shift of the rain belt which had flooded the catchment basin of the Nile eventually extended to the Nile valley itself, and across the adjacent Sahara. Conservative assessments conclude that regular annual rains began to fall on the region from about 11,000 years ago; 14 additional rain in the valley can hardly have been viewed as compensation for the devastating floods its inhabitants had suffered, but in the desert increased rainfall produced an environment to which some of the survivors could migrate. The scene that greeted them, however, was not one of lush vegetation and teeming wildlife.
The Sahara was only partially transformed. Semi-desert best describes its open landscape of wild grasses and thorn bush, sparsely relieved by the occasional acacia and tamarisk tree, and inhabited only by animals that could tolerate arid conditions. Surface water was concentrated in and around the highlands, or in the lakes and ponds that formed in localized depressions. People congregated around these bodies of water, and were occupying such sites throughout the Sahara by about 8,500 years ago.15
Not all the newcomers were migrants who had left the Nile valley in the aftermath of the catastrophic floods. The flush of growth which the rains cast across the desert at that time attracted people from all around the Sahara, but the oldest-known sites from the period are undoubtedly those situated within a few hundred kilometres of the Nile; and the evidence of Nile Valley food-production strategies is found also at younger sites across the breadth of the Sahara, suggesting that if not the people of the Nile themselves, then at least their cultural adaptations had played a role in the repopulation of the former desert.
]]>The domestication of cattle, goats, and sheep was a crucial factor in the reoccupation of the Sahara at this time, for the herding of livestock was fundamental to the food-production strategies that enabled people to live permanently in the Sahara. Domesticated animals not only converted otherwise inedible vegetation into meat that could be harvested more easily than by hunting, they also constituted a resource that could be utilized on a continuous basis. As long as the animals had access to sufficient grazing and water they could provide people with supplementary supplies of nourishment, such as milk.
in times of political and intellectual regression, the mainstream is the official arbiter of interpretation – as long as it is not challenged.
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