by Peter Watson
One reason for the distribution about the globe of these areas has been provided by Andrew Sherratt, from the Ashmolean Museum in Oxford. His theory is that three of these areas–the Middle East, Mesoamerica and the south-east Asian island chain–are what he calls ‘hot spots’: geologically and geographically they have been regions of constant change, where incredible pressures generated by tectonic plates moving over the surface of the earth created in these three places narrow isthmuses, producing a conjunction of special characteristics that are not seen elsewhere on earth. These special characteristics were, first, a sharp juxtaposition of hills, desert and alluvium (deposits of sand or mud formed by flowing water) and, second, narrow strips of land which caused a build-up of population so that the isthmus could not support traditional hunter-gathering.4 These ‘hot spots’ therefore became ‘nuclear areas’ where the prevailing conditions made it more urgent for early man in those regions to develop a different mode of subsistence.
Whatever the truth of this attractively simple theory, or in regard to the number of times agriculture was ‘invented’, there is little doubt that the very first time, chronologically speaking, that plants and animals were domesticated, was in the ‘fertile crescent’ of south-west Asia. To understand fully what we are talking about we need to grasp the nature of the evidence about domestication, which means in the first instance understanding the relatively new science of palynology, or pollen analysis. Plants–especially the wind-pollinated tree species–each produce thousands of pollen grains every year, the outer skins of which are very tough, and very resistant to decay. Pollen varies in shape and size and, being organic, can be carbon-dated. Its age and genus, if not its species, can therefore often be determined and this has enabled archaeo-botanists (a relatively new specialism) to reconstruct the surface vegetation of the earth at different periods in the past.
Plant remains (i.e., not just pollen) have now been identified and radio-carbon dated from hundreds of sites in the Middle East and, according to the Israeli geneticist Daniel Zohary, the picture is more or less clear. First, there were three cereals which formed the principal ‘founder crops’ of Neolithic agriculture. In order of importance, these were: emmer wheat (Triticum turgidum, subspecies dicoccum), barley (Hordeum vulgare) and einkorn wheat (Triticum monococcum). They first appeared in the tenth and ninth millennia BP. Second, the domestication of these cereals was accompanied by the cultivation of several ‘companion plants’, in particular the pea (Pisum sativum), the lentil (Lens culaniris), the chickpea (Cicer arietinum), bitter vetch (Vicia ervilia) and flax (Linum usitatissimum).5 In each case, the original wild variety, from which the domestic crop evolved, has now been identified; this enables us to see what advantages the domestic variants had over their wild cousins. In the case of einkorn wheat, for example, the main distinguishing trait between wild and cultivated varieties lies in the biology of seed dispersal. Wild einkorn has brittle ears, and the individual spikelets break up at maturity to disperse the seed. In the cultivated wheat, on the other hand, the mature ear is less brittle, stays intact, and will break only when threshed. In other words, to survive it needs to be reaped, and then sown. The same is true for the other crops: the domesticated varieties were less brittle than the wild types, so that the seeds are spread only once the plant has been reaped, thereby putting it under man’s control. Comparison of the DNA of the various wheats all over the fertile crescent shows that they are fundamentally identical, much less varied than the DNA of wild wheats. This suggests that in each case domestication occurred only once. ‘The plants with which food production started in the South West Asia “nuclear area” were transported (already as domesticated crops) to initiate agriculture all over these vast territories.’6
A number of specific sites have been identified where domestication may have first occurred. Among these are Tell Abu Hureyra and Tell Aswad in Syria, which date back to 10,000 years ago, Karacada(gcirck) in Turkey, Netiv Hagdud, Gilgal and Jericho, in the Jordan valley, and Aswan in the Damascus basin, also in Syria, which date back even further, to 12,000–10,500 BP. An alternative theory–still speculative–is that man’s increasing control of fire enabled him to burn huge tracts of forest, and that the tender grasses and shoots that would have grown up amid the burnt remains would themselves have been, in effect, domesticated plants and would have attracted herbivorous game.7 This would have needed a knowledge of ‘slash and burn’ technology and tools sufficient to cut down large trees–to create fire-breaks. It is by no means certain that early humans had such tools.
In the case of animal domestication the type of evidence is somewhat different. In the first place we should note that the general history of the earth helped somewhat: after the last ice age most species of mammal were smaller than hitherto.8 One or more of three criteria are generally taken as evidence of domestication: a change in species abundance–a sudden increase in the proportion of a species within the sequence of one site; a change in size–most wild species are larger than their domestic relatives, because humans found it easier to control smaller animals; and a change in population structure–in a domestic herd or flock, the age and sex structure is manipulated by its owners to maximise outputs, usually by the conservation of females and the selection of sub-adult males. Using these criteria, the chronology of animal domestication appears to begin shortly after 9000 BP–that is, about 1,000 years after plant domestication. The sites where these processes occurred are all in the Middle East, indeed in the fertile crescent, at locations which are not identical to, but overlap with those for plant domestication. They include Abu Hureyra, at 9400 BP, Ganj Dareh in Iran, at 9000–8450 BP, Gritille in Turkey, at 8600–7770 BP, and Tell Aswad, Jericho, Ramad, ’Ain Ghazal, Beida and Basta, all just post-dating 9000 BP. In most cases, the sequence of domestication is generally taken to be: goats then sheep, to be closely followed by pigs and cattle. ‘The transformation from a hunting and collecting economy, perhaps beginning with the cultivation of wild cereals, to the establishment of permanent villages and a mixed agricultural economy with fully domesticated races of plants and animals, took place over at least 3,000 years.’ There was no radical break; for many years people simply tended ‘wild gardens’ rather than neat smallholdings or farms as we would recognise them. There was a transition period where hunter-gatherers culled smaller animals. Pigs do not adjust to the nomadic way of life, so their domestication implies sedentism.9
So far as animal domestication is concerned, it first took place in the hilly/mountainous region where modern-day Iran, Iraq and Turkey meet, the most likely reason for this being that, in a situation where most wild species were not naturally domesticable, hilly regions (with a variety of altitudes and therefore of vegetation) would have produced the greatest range of animal species, and the greatest variation of individuals within species. Such an environment would have been the most likely to have produced smaller types, more amenable to control.
For the Old World, then, the location and timing of agriculture is understood, as are the plants and animals on which it was based. Further, there is a general agreement among palaeobiologists that domestication was invented only once and then spread to western Europe and India. Whether it also spread as far afield as south-east Asia and central Africa is still a moot point, and the most recent genetic evidence of farmers (as opposed to their plants) is not as conclusive as it might be. It shows that modern-day Greeks share 85–100 per cent of their (relevant) genes with Middle Easterners (from Baghdad, Ankara and Damascus), whereas Parisians share only 15–30 per cent. Some archaeologists have suggested that this means that it wasn’t the idea that spread, but people practising the idea, but not everyone accepts this.10
Much more controversial, however, are the reasons for why agriculture developed, why it developed then, and why it developed where it did. This is clearly of major importance in understanding mankind’s mental development. It is also an even more interesting question than it looks when you consider the fact that the hunter
-gathering mode is actually quite an efficient way of leading one’s life. Ethnographic evidence among hunter-gatherer tribes still in existence shows that they typically need to ‘work’ only three or four or five hours a day in order to provide for themselves and their kin. Skeletal remains of Stone Age farmers reveal more signs of malnutrition, infectious diseases and dental decay than those of their hunter-gatherer predecessors. Why, therefore, would one change such a set of circumstances for something different where one has to work far harder? In addition, reliance on grain imposed a far more monotonous diet on early humans than they had been used to in the time of hunting and gathering. In any case, when people first domesticated crops, these remained a minor part of the diet for centuries, possibly more than a thousand years. Again, why the change?
One theory is that the switch to agriculture was made for ritualistic or social reasons, because the new foods were rare luxuries, which gradually spread, the way designer goods do in our own day. Lentils, for example, grow just two per wild plant and would hardly have staunched the hunger of a Stone Age family. Yet lentils are among the first crops of the Near East. Some palaeontologists feel beer was the most important end-product of these grains, the importance of alcohol in a ritual feast being obvious.
But the most basic of the economic arguments stems from the fact that, as has already been mentioned, some time between 14,000 and 10,000 BP, the world suffered a major climatic change. This was partly a result of the end of the Ice Age which had the twin effects of raising sea levels and, in the warmer climate, encouraging the spread of forests. These two factors ensured that the amount of open land shrank quite dramatically, ‘segmenting formerly open ranges into smaller units and arranging the niches for different species by altitude and type of vegetation…Sedentism and the reduction of open range encouraged territoriality. People began to protect and propagate local herds, a pre-domestication practice that can be referred to as food resource management.’11 A further aspect of this set of changes was that the climate became increasingly arid, and the seasons became more pronounced, a circumstance which encouraged the spread of wild cereal grasses and the movement of peoples from one environment to the next, in search of both plants and animal flesh. There was more climatic variety in areas which had mountains, coastal plains, higher plains and rivers. This accounts for the importance of the fertile crescent. Grasses were naturally prevalent in this Near Eastern region (wild stands of emmer and einkorn wheat, and barley, exist there to this day). But it is not difficult to work out what happened. ‘The harvested batch of seeds would be selected in favour of non-shattering and uniform maturation. As soon as humans began to sow the seeds they had harvested, they automatically–even if unintentionally–initiated a process of selection in favour of the non-shattering genotype.’12
Mark Nathan Cohen is the most prominent advocate of the theory that there was a population crisis in pre-history and that it was this which precipitated the evolution of agriculture. Among the evidence he marshals to support his argument is the fact that agriculture is not easier than hunter-gathering, that there is a ‘global coincidence’ in the simultaneous extinction of mega-fauna, the big mammals which provided so much protein for early humans, a further coincidence that domestication emerged at the end of the Pleistocene Age, when the world warmed up and people became much more mobile, and that the cultivation of wild species, before agriculture proper, encouraged the birth of more children. It is well known, for instance, that nomads and hunter-gatherers control the number of children by not weaning them for two years. This limits the size of a group that is continually on the move. After the development of sedentism, however, this was no longer necessary, and resulted, says Cohen, in a major population explosion. Cohen also claims that evidence for a population crisis in antiquity can be inferred from the number of new zones exploited for food, the change in diet, from plants which need less preparation to those which need more, the change in diet from larger animals to smaller (because larger ones were extinct), the increasing proportion of remains of people who are mal-nourished, the specialisation of artefacts which had evolved to deal with rarer and rarer animals and plants, the increased use of fire, for cooking otherwise inedible foodstuffs, the increased use of aquatic resources, the fact that many plants, though available as food in deep antiquity, were not harvested until around 12,000 BP, that grass (cereals) is a low priority in food terms, and so on and so on, all of which Cohen contends is corroborated by archaeological excavation. For him, therefore, the agricultural revolution was not, in and of itself, a liberation for early humans. It was instead a holding action to cope with the crisis of overpopulation. Far from being an inferior form of life, the hunter-gatherers had been so successful they had filled up the world, insofar as their lifestyle allowed, and there was no place to turn.13
It is another attractively simple hypothesis but there are problems with it. One of the strongest criticisms comes from Les Groube, who is the advocate of a rival theory. According to Groube, who is based in France, it is simply not true that the world of deep antiquity was in a population crisis, or certainly not a crisis of overpopulation. His argument is the opposite, that the relatively late colonisation of Europe and the Americas argues for a fairly thinly populated Earth. For Groube, as man moved out of Africa into colder environments, there would have been fewer problems with disease, simply because, from a microbial point of view, the colder regions were safer, healthier. For many thousands of years, therefore, early man would have suffered fewer diseases in such places as Europe and Siberia, as compared with Africa. But then, around 20,000 years ago, an important coincidence took place. The world started to warm up, and man reached the end of the Old World–meaning that, in effect, the known world was ‘full’ of people. There was still plenty of food but, as the world warmed up, many of the parasites on man were also able to move out of Africa. In short, what had previously been tropical diseases became temperate diseases as well. The diseases Groube mentions include malaria, schistosomiasis and hookworm, ‘a terrible trinity’. A second coincidence also occurred. This was the hunting to extinction of the mega-fauna, which were all mammals, and therefore to a large extent biologically similar to man. All of a sudden (sudden in evolutionary terms), there were far fewer mammals for the microbial predators to feast on–and they were driven to man.14
In other words, sometime after 20,000 years ago, there was a health crisis in the world, an explosion of disease that threatened man’s very existence. According to Groube’s admittedly slightly quirky theory, early humans, faced with this onslaught of disease, realised that the migrant pattern of life, which limited childbirth to once every three years or so, was insufficient to maintain population levels. The change to sedentism, therefore, was made because it allowed people to breed more often, increase numbers, and avoid extinction.
One thing that recommends Groube’s theory is that it divorces sedentism from agriculture. This discovery is one of the more important insights to have been gained since the Second World War. In 1941, when the archaeologist Gordon Childe coined the phrase ‘The Neolithic Revolution’, he argued that the invention of agriculture had brought about the development of the first villages and that this new sedentary way of life had in turn led to the invention of pottery, metallurgy and, in the course of only a few thousand years, the blossoming of the first civilisations.15 This neat idea has now been overturned, for it is quite clear that sedentism, the transfer from a hunter-gathering lifestyle to villages, was already well under way by the time the agricultural revolution took place. This has transformed our understanding of early man and his thinking.
Although present-day ‘stone age’ tribes are by no means a perfect analogue of ancient hunter-gatherers (for one thing, they tend to occupy marginal areas), it has become clear that ‘primitive’ peoples do have an intimate knowledge of the natural world in which they live. And, although they may not practise full-scale agriculture, they certainly cultivate both plants and animals, in the sense of clea
ring areas and planting grasses or vegetables or fruits. They sow, drain and irrigate, they practise rough herding and ‘free range movement’. They keep pet mammals and birds and are fully aware of the medicinal qualities of certain herbs. This is surely a half-way stage between the old idea of hunter-gatherers and full-blown agriculture. By the same token, ‘there is now a considerable body of evidence in support of the view that some resource-rich locations in the Levant were occupied year-round during the terminal Pleistocene (more specifically in the Natufian and Khiamian periods: c. 10,500–8300 BC) by “sedentary foragers” who developed…techniques of plant exploitation, including storage and possibly small-scale cultivation…and who lived year round in settlements of up to half a hectare in area’.16
The fact that sedentism preceded agriculture has stimulated the French archaeologist Jacques Cauvin to produce a wide-ranging review of the archaeology of the Middle East, which enables him to reconcile many developments, most notably the origins of religion and the idea of the home, with far-reaching implications for the development of both our basic and our more speculative/philosophical innovations. If tools and the control of fire were the first ideas, clothing and shelter soon followed.