Population Crises and Population Cycles

11. Some Societies without Recorded History

The Incas suppressed the Chimu invention of writing, but their history was written just after the Conquest. We can now consider some societies without written records (or at least decipherable ones), but whose population crises and cycles can be revealed by spoken tradition, travellers’ tales, and/or archaeological evidence.

In Upper Palaeolithic (Late Old Stone Age) Europe, a moderate estimated population of about 150,000 hunter-gatherers were supplied with a wealth of natural resources. They produced a wonderful cultural flowering, with continent-wide peace and culture reflected in the distribution of trade-goods and art forms (Mediterranean shells reached the Middle Dnieper), records on bone (probably made by women) of scientific observations on lunar phases and seasonal phenomena, and marvels of accurate representational art to teach game zoology in cave-universities. Then in the ninth millennium BC, when the population had increased dangerously to over 200,000, the glaciers receded, the climate changed, and the big game herds dwindled and became extinct. Unable to reduce their populations in time, the Europeans suffered a major crisis. In Catalonian rock pictures battle scenes appeared, in the cave of Addaura near Palermo, bird-masked priests were depicted sacrificing garrotted human victims, and over-hunting probably hastened the extinction in Europe of the musk-ox, mammoth and woolly rhinoceros. The human population dropped substantially, until new types of food procurement developed, ‘broad-spectrum gathering’, which used a great diversity of plant and animal resources.

In the sixth and fifth millennia BC, the first farmers spread over Europe. They were confined to the loess soils which formed a corridor across the continent, well drained, easy to till with stone tools, and covered with woodland sparser than that occupying the rest of Europe. They practised a primitive form of shifting cultivation, simply moving on when the soil of a plot was exhausted. While there was still plenty of loess land to expand into, their villages were unfortified and their graves contained only peaceful tools. But eventually they ran out of land, population crisis set in, and fortifications and weapons appeared. At Köln-Lindenthal near Cologne, an earlier village of twenty-seven households was merely fenced against wild beasts; when the same site was later re-occupied, thirty-five households were protected by a defensive ditch and rampart, which must have cost nearly three thousand man-days of labour.

As we saw in the tenth paper, in the wet tropics shifting cultivation evolved into the sophisticated system of swidden farming. In Europe, except (until very recently) in Sweden, Finland and Russia, it was soon replaced by settled mixed farming with stock and crops. As we saw in the sixth paper, in historic times the farmers concentrated on crops during crises, and on stock during relief periods. In Iron Age Southern Britain, during the first millennium BC, similar alternations of crop and stock farming can be demonstrated by archaeological evidence. At one time, grazing paddocks appeared, whose earthwork boundaries cut across abandoned fields. Then paddock construction stopped for a time, and very large grain storage pits indicated a return to crop agriculture. At the end of the millennium, new kinds of cattle and sheep enclosures were being constructed, showing that stock raising was important again. We can therefore infer the occurrence in prehistoric Britain of population crises and cycles with the same effects on agriculture as those of medieval and early modern Europe.

Near the mouth of the Niger in what is now Nigeria, the kingdom of Benin, founded in the thirteenth century AD, was based on swidden farming, and reproduces on a small scale the same kind of population crisis as that of the Maya. In its earlier centuries, the kingdom produced bronzes, brasses, terracottas and ivories which are among the glories of world art. In 1602, a Dutch writer compared Benin City, not unfavourably, with Amsterdam, then the greatest trading city of Europe. Eventually, however, Benin art and civilisation began to decline, and ‘later degeneration seems to have gone hand in hand with kingly autocracy and an increase in human sacrifice’ (Davidson, 1959). When a British Punitive Expedition entered Benin City in 1897, their leaders found it ‘a collection of half-ruined mud houses’, depopulated by civil war and human sacrifice - ‘down every main road were two or more human sacrifices … blood was everywhere’. The forest that now covers much of this region bears abundant traces of past swidden clearance, present-day Benin soil is notoriously poor, and everything suggests that the kingdom experienced a Maya-type population crisis.

Another possible case of this sort, known only from archaeological evidence, is the group of complex cultures that flourished in the Amazon and Orinoco valleys in the eleventh to thirteen centuries AD. They had elaborate ceremonials and excellent painted pottery, probably made by specialist craft workers. In the words of Josephy (1969), ‘in the tropical forest environment, these cultures could not endure and continue their development to higher levels; inevitably, agricultural yields declined, villages were forced to move … and advanced cultures collapsed’.

In the North-East of Black Mesa in North-Eastern Arizona, an extensive study has been made of occupation sites of the Anasazi people ("ancient ones" in the Navaho language). Changes in the total floor area of their dwellings, shown in the graph, give a good idea of relative changes in their population.

In what are now the States of Utah, Colorado, Arizona and New Mexico, a people known as the Anasazi developed an impressive culture between the eighth and the thirteenth century AD, with fine pottery, textiles and jewellery. They practised farming naturally irrigated by flash-floods, and dry farming in the uplands. Eventually their populations grew far too large for their resources, malnutrition set in, and finally the populations crashed, the survivors moving to new sites. This happened at different times in different parts of their range: the sequence on Black Mesa in North-Eastern Arizona is shown in Figure 1. In Southern Arizona, the even more impressive culture of the Hohokam flourished between the seventh and the fifteenth centuries. They constructed enormous irrigation canals - one network covers one hundred and fifty miles - carefully lined with clay to prevent leakage, they made fine pottery, textiles and figurines, and they ‘developed a process of etching shells with fermented saguaro juice, making probably the first etchings in the world’ (Josephy, 1969). But they too became overpopulated, experienced population crisis and crash, the culture collapsed and the canals were abandoned.

We saw in the first paper that population crises in historic societies have often involved massive building operations, designed to absorb surplus labour. The building of stupendous mounds was a feature of three prehistoric cultures of the Eastern Woodlands of the United States, the Adena and Hopewell peoples centred on the Ohio valley, and the Temple Mound builders centred on that of the Mississippi. The Great Serpent Mound in Adams County, Ohio, probably an Adena construct and formed like a huge snake, is ‘nearly a quarter of a mile long’ (Silverberg, 1974). The Ohio peoples generally made conical burial mounds, the Mississippians flat-topped temple mounds. All three cultures made fine works of art, and the Hopewell people were notable for trading as far as the Rockies, the Great Lakes. and the Gulf and Atlantic Coasts. All three eventually showed the usual effects of over-population - the Hopewell in particular enormous fortifications - and all three finally experienced population crash and culture collapse, the Ohio cultures in the fifth century, the Mississippians (who began later) in the twelfth century AD. It is surprising they achieved so much, since they were based only partly on farming and partly on broad-spectrum gathering.

The population estimates before 1790 are based on archaeological evidence.  The islands were settled about 100 BC. Population grew very steeply in the couple of centuries before AD 1100. There may have been a short crash before population rose again to its peak in about AD 1500. The following crash began long before the European impact began in about AD 1790, though it was then somewhat steepened by the import of European diseases and of fire-arms, which enabled the Marquesans’ internecine wars to be even more destructive.

The islands of the Pacific began to be colonised from South-East Asia during the second millennium BC. The farthest islands were discovered and settled by the Polynesians, the finest seafarers in the world, who could (and still can) navigate hundreds of miles by the stars, and detect land 45 miles away by the pattern of ocean swells. The Marquesas in the Eastern Pacific were settled about 100BC. At first the settlers lived in the well-watered Eastern parts of the islands. Copious supplies of a high-energy food, the breadfruit, promoted a growth of population, which by about AD 1100 was far in excess of available resources. The islanders occupied the marginal arid areas on the West coasts, and colonised the smaller islands of the group, but this did not prevent a fearful population crisis from setting in. Massive temples and fortifications were built, sling-stones were produced in large numbers, and ferocious warfare and cannibalism prevailed for centuries. When the Europeans arrived in appreciable numbers after about 1790, the population crash was well under way, as shown in Figure 2, and general lowered resistance due to stress was probably, as in Mexico, at least as important as lack of specific immunity in causing high mortality from imported European diseases. Warfare and cannibalism continued well into the period of European contact, and the population was finally reduced by over 90%.

In the fourth century AD, a party of Marquesans colonised Easter Island. Here too population was growing rapidly by the end of the first millennium AD, giving rise to an outburst of building that produced temples with the famous gigantic heads that are today’s main tourist attraction. By the sixteenth century, the population reached about eight thousand, on a not very fertile island of some 160 square kilometres. Savage warfare, in which children and old people were massacred, cannibalism, famines and epidemics reduced the population to its present-day number of about two thousand. But meanwhile the resources of the island had been virtually totally destroyed. The palm forests were gone by the end of the seventeenth century, so that ocean-going boats could no longer be constructed to exploit the lavish off-shore fisheries, and the islanders had extinguished several bird species and driven others to nest on off-shore islets only to be reached by swimming through ‘treacherous (and occasionally shark-infested) waters’ (Tilburg, 1994). The island’s history shows very clearly that, as stated in our first paper, ‘the crisis responses in man have not been able to achieve their evolutionary function in time’ to prevent depletion and destruction of resources. It has been considered as a warning of what might happen to the natural environment of mankind as a whole.