AGRICULTURE'S TWO-EDGED SWORD
Agriculture is conventionally regarded as the human hallmark whose adoption made the biggest material contribution to the improvement in our lifestyle over that of apes. In fact, recent archaeological studies have made it clear that agriculture brought many of the curses as well as the blessings of modern civilization.
To science, we owe dramatic changes in our smug self-image. Astronomy taught us that our Earth is not the centre of the universe but merely one of nine planets circling one of billions of stars. From biology, we learned that humans were not specially created by God but evolved along with tens of millions of other species. Now, archaeology is demolishing another sacred belief: that human history over the last million years has been a long tale of progress. In particular, recent discoveries suggest that the adoption of agriculture (plus animal husbandry), supposedly our most decisive step towards a better life, was actually a milestone for the worse as well as for the better. With agriculture came not only greatly increased food production and food storage, but also the gross social and sexual inequality, the disease and despotism, that curse modern human existence. Thus, among the human cultural hallmarks being discussed in Part Three of this book, agriculture represents in its mixed blessings a halfway station between our noble traits discussed in Chapters Eight and Nine (art and language) and our unmitigated vices, discussed in many of the remaining chapters (drug abuse, genocide, and environmental destructiveness).
At first, the evidence for progress and against this revisionist interpretation will strike twentieth-century Americans and Europeans as irrefutable. We are better off in almost every respect than people of the Middle Ages, who in turn had it easier than Ice-Age cavemen, who were still better off than apes. If you are inclined to be cynical, just count our advantages. We enjoy the most abundant and varied food, the best tools and material goods, the longest and healthiest lives in human history. Most of us are safe from starvation and predators. We obtain most of our energy from oil and machines, not just from our sweat. What neo-Luddite among us would really trade the life of today for that of a medieval peasant, caveman, or ape? For most of our history, all humans had to practise a primitive lifestyle termed 'hunting and gathering': they hunted wild animals and gathered wild plant food. That hunter-gatherer lifestyle is often characterized by anthropologists as 'nasty, brutish, and short'. Since no food is grown and little is stored, there is (according to this view) no respite from the time-consuming struggle that starts anew each day to find wild foods and avoid starving. Our escape from this misery was launched only after the end of the last Ice Age, when people began independently in different parts of the world to domesticate plants and animals (see Chapter Fourteen). The agricultural revolution gradually spread until today it is nearly universal and few tribes of hunter-gatherers survive. From the progressivist perspective on which I was brought up, the question 'Why did almost all our hunter-gatherer ancestors adopt agriculture? is silly. Of course they adopted it because agriculture is an efficient way to get more food for less work. Our planted crops yield far more tons per acre than do wild roots and berries. Just imagine savage hunters, exhausted from searching for nuts and chasing wild animals, suddenly gazing for the first time at a fruit-laden orchard or a pasture full of sheep. How many milliseconds do you think it took those hunters to appreciate the advantages of agriculture?
The progressivist party line goes further and credits agriculture with giving rise to art, the noblest flowering of the human spirit. Since crops can be stored, and since it takes less time to grow food in gardens than to find it in the jungle, agriculture gave us free time that hunter-gatherers never had. But free time is essential for creating art and enjoying it. Ultimately it was agriculture that, as its greatest gift, enabled us to build the Parthenon and compose the B Minor Mass. Among our major cultural hallmarks, agriculture is especially recent, having begun to emerge only 10,000 years ago. None of our primate relatives practises anything remotely resembling agriculture. For the most similar animal precedents, we must turn to ants, which invented not only plant domestication but also animal domestication.
Plant domestication is practised by a group of several dozen related species of New World ants. All those ants cultivate specialized species of yeasts or fungi in gardens within the ants' nest. Rather then relying on natural soil, each gardener ant species gathers its own particular type of compost: some ants grow their crop on caterpillar faeces, others on insect corpses or dead plant material, and still others (the so-called leaf-cutter ants) on fresh leaves, stems, and flowers. For example, leaf-cutter ants clip off leaves, slice them into pieces, scrape off foreign fungi and bacteria, and take the pieces into underground nests. There the leaf fragments are crushed into moist pellets of a paste-like consistency, manured with ant saliva and faeces, and seeded with the ants' preferred species of fungus, which serves as the ants' main or sole food. In an operation the equivalent of weeding a garden, the ants continually remove any spores or threads of other fungus species that they may find growing on their leaf paste. When a queen ant goes off to found a new colony, she carries with her a starting culture of the precious fungus, just as human pioneers bring along seeds to plant.
As for animal domestication, ants obtain a concentrated sugary secretion termed honeydew from diverse insects, ranging from aphids, caterpillars, and mealybugs to scale insects, treehoppers, and spittle insects. In return for the honeydew, the ants protect their 'cows' from predators and parasites. Some aphids have evolved into virtually the insect equivalent of domestic cattle: they lack offensive structures of their own, excrete honeydew from their anus, and have a specialized anal anatomy designed to hold the droplet in place while an ant drinks it. To milk their cow and stimulate honeydew flow, ants stroke the aphid with their antennae. Some ants care for their aphids in the ants' nest during the cold winter, then in the spring carry the aphids at the correct stage of development to the correct part of the correct food plant. When aphids eventually develop wings and disperse in search of a new habitat, some lucky ones are discovered by ants and 'adopted'.
Obviously, we did not inherit plant and animal domestication directly from ants but reinvented it. Actually, 're-evolved' is a better term than 'reinvented', since our early steps towards agriculture did not consist of conscious experimentation towards an articulated goal. Instead, agriculture grew from human behaviours, and from responses or changes in plants and animals, leading unforeseen towards domestication. For example, animal domestication arose partly from people keeping captive wild animals as pets, partly from wild animals learning to profit from the proximity of people (such as wolves following human hunters to catch crippled prey). Similarly, early stages of plant domestication included people harvesting wild plants and discarding seeds, which were thereby accidentally 'planted'. The inevitable result was unconscious selection of those plant and animal species and individuals most useful to humans. Eventually, conscious selection and care followed.
Now let's return to the progressivist view of this agricultural revolution of ours. As I explained at the outset of this chapter, we are accustomed to assuming that the transition from the hunter-gatherer lifestyle to agriculture brought us health, longevity, security, leisure, and great art. While the case for this view seems overwhelming, it is hard to prove. How do you actually show that lives of people 10,000 years ago got better when they abandoned hunting for farming? Until recently, archaeologists could not test this question directly. Instead, they had to resort to indirect tests, whose results (surprisingly) failed to support the view of agriculture as an unmixed blessing. Here is one example of such an indirect test. If agriculture had been visibly such a great idea, you would expect it to have spread quickly, once it arose in some source area. In fact, the archaeqlogical record shows that agriculture advanced across Europe at literally a snail's pace: barely 1,000 yards per year! From its origins in the Near East around 8000 BC, agriculture crept north-westwards to reach Greece around 6000 BC and Britain and Scandinavia only 2,500 years later. That is hardly what you can call a wave of enthusiasm. As recently as the Nineteenth Century, all the Indians of California, now the fruit-basket of America, remained hunter-gatherers, even though they knew of agriculture through trade with farming Indians in Arizona. Were California Indians really blind to their self-interest? Or, could it instead be that they were smart enough to see, hidden beyond agriculture's glittering facade, the drawbacks that ensnared the rest of us?
Another indirect test of the progressivist view is to study whether surviving twentieth-century hunter-gatherers really are worse off than farmers. Scattered throughout the world, mainly in areas unsuitable for agriculture, several dozen groups of so-called 'primitive people', like the Kalahari Desert Bushmen, continued to live as hunter-gatherers in recent years. Astonishingly, it turns out that these hunters generally have leisure time, sleep a lot, and work no harder than their farming neighbours. For instance, the average time devoted each week to obtaining food has been reported to be only twelve to nineteen hours for Bushmen; how many readers of this book can boast of such a short working week? As one Bushman replied when asked why he had not emulated neighbouring tribes by adopting agriculture, 'Why should we plant, when there are so many mongongo nuts in the world?
Of course, one's belly is not filled only by finding food; the food also has to be processed for eating, and that can take a lot of time for things like mongongo nuts. It would be a mistake to swing to the opposite extreme from the progressivist view and to regard hunter-gatherers as living a life of leisure, as some anthropologists have done. However, it would also be a mistake to view them as working much harder than farmers. Compared to my physician and lawyer friends today, and to my shopkeeper grandparents in the early Twentieth Century, hunter-gatherers really do have more free time.
While farmers concentrate on high-carbohydrate crops like rice and potatoes, the mixture of wild plants and animals in the diets of surviving hunters provides more protein and a better balance of other nutrients. The Bushmen's average daily food intake is 2,140 calories and 93 grams of protein, considerably greater than the US RDA (Recommended Daily Allowance) for people of their small size but vigorous activity. Hunters are healthy, suffer from little disease, enjoy a very diverse diet, and do not experience the periodic famines that befall farmers dependent on few crops. It is almost inconceivable for Bushmen, who utilize eighty-five edible wild plants, to die of starvation, as did about a million Irish farmers and their families during the 1840s when a blight attacked potatoes, their staple crop.
Thus, the lives of at least the surviving modern hunter-gatherers are not 'nasty, brutish, and short', even though farmers have pushed them into the world's worst real-estate. Hunters of the past, who still occupied fertile lands, could hardly have been worse off than modern hunters. However, all those modern hunter societies have been affected by farming societies for thousands of years and do not tell us about the condition of hunters before the agricultural revolution. The progressivist view is really making a claim about the distant past: that the lives of people in each part of the world got better when they switched from hunting to farming. Archaeologists can date that switch by distinguishing remains of wild plants and animals from remains of domestic ones in prehistoric rubbish dumps. How can one deduce the health of the prehistoric rubbish makers, and thereby test directly for agriculture's supposed blessings?
That question has become answerable only in recent years, through the newly emerging science of'paleopathology': looking for signs of disease (the science of pathology) in remains of ancient peoples (from the Greek word paieo meaning 'ancient', as in paleontology). In some lucky situations, the paleopathologist has almost as much material to study as does a pathologist. For example, archaeologists in the deserts of Chile found well-preserved mummies whose medical condition at time of death could be determined by an autopsy, just as one would do on a fresh corpse in a hospital today. Faeces of long-dead Indians who lived in dry caves in Nevada remained sufficiently well-preserved to examine for hookworm and other parasites.
Usually, though, the only human remains available for paleo-pathologists to study are skeletons, but they still permit a surprising number of deductions about health. To begin with, a skeleton identifies its owner's sex, and his/her weight and approximate age at time of death. Thus, with enough skeletons, one can construct mortality tables like those used by life insurance companies to calculate expected lifespan and risk of death at any given age. Paleopathologists can also calculate growth rates by measuring bones of people of different ages, can examine teeth for cavities (signs of a high-carbohydrate diet) or enamel defects (signs of a poor diet in childhood), and can recognize scars that many diseases such as anaemia, tuberculosis, leprosy, and osteoarthritis leave on bones.
One straightforward example of what paleopathologists have learned from skeletons concerns historical changes in height. Many modern cases illustrate how improved childhood nutrition leads to taller adults: for instance, we stoop to pass through doorways of medieval castles built for a shorter, malnourished population. Paleopathologists studying ancient skeletons from Greece and Turkey found a striking parallel. The average height of hunter-gatherers in that region towards the end of the Ice Age was a generous 5 foot 10 inches for men, 5 foot 6 inches for women. With the adoption of agriculture, height crashed, reaching by 4000 BC a low value of only 5 foot 3 inches for men, 5 foot 1 inch for women. By classical times, heights were very slowly on the rise again, but modern Greeks and Turks have still not regained the heights of their healthy hunter-gatherer ancestors.
Another example of paleopathologists at work is the study of thousands of American Indian skeletons excavated from burial mounds in the Illinois and Ohio River valleys. Corn, first domesticated in Central America thousands of years ago, became the basis of intensive farming in those valleys around 1000 AD. Until then, Indian hunter-gatherers had skeletonsjso healthy it is somewhat discouraging to work with them', as one paleopathologist complained. With the arrival of corn, Indian skeletons suddenly became interesting to study. The number of cavities in an average adult's mouth jumped from less than one to nearly seven, and tooth loss and abscesses became rampant. Enamel defects in children's milk teeth imply that pregnant and nursing mothers were severely undernourished. Anaemia quadrupled in frequency; tuberculosis became established as an epidemic disease; half the population suffered from yaws or syphilis; and two-thirds suffered from osteoarthritis and other degenerative diseases. Mortality rates at every age increased, with the result that only one per cent of the population survived past the age of fifty, as compared to five per cent in the golden days before corn. Almost one-fifth of the whole population died between the ages of one and four, probably because weaned toddlers succumbed to malnutrition and infectious diseases. Thus, corn, usually considered among the New World's blessings, actually proved to be a public health disaster. Similar conclusions about the transition from hunting to farming emerge from studies of skeletons elsewhere in the world.
There are at least three sets of reasons to explain these findings that agriculture was bad for health. Firstly, hunter-gatherers enjoyed a varied diet with adequate amounts of protein, vitamins, and minerals, while farmers obtained most of their food from starchy crops. In effect, the farmers gained cheap calories at the cost of poor nutrition. Today just three high-carbohydrate plants—wheat, rice, and corn—provide more than fifty per cent of the calories consumed by the human species.
Secondly, because of that dependence on one or a few crops, farmers ran a greater risk of starvation if one food crop failed than did hunters. The Irish potato famine is merely one of many examples.
Finally, most of today's leading infectious diseases and parasites of mankind could not become established until after the transition to agriculture. These killers persist only in societies of crowded, malnourished, sedentary people constantly reinfected by each other and by their own sewage. The cholera bacterium, for example, does not survive for long outside the human body. It spreads from one victim to the next through contamination of drinking water with faeces of cholera patients. Measles dies out in small populations once it has either killed or immunized most potential hosts; only in populations numbering at least a few hundred thousand people can it maintain itself indefinitely. Such crowd epidemics could not persist in small, scattered bands of hunters who often shifted camp. Tuberculosis, leprosy, and cholera had to await the rise of farming, while smallpox, bubonic plague, and measles appeared only in the past few thousand years with the rise of cities.
Besides malnutrition, starvation, and epidemic diseases, farming brought another curse to humanity—class divisions. Hunter-gatherers have little or no stored food, and no concentrated food sources such as an orchard or herd of cows. Instead, they live off the wild plants and animals that they obtain each day. Everybody except for infants, the sick, and the old joins in the search for food. Thus, there can be no kings, no full-time professionals, no class of social parasites who grow fat on food seized from others.
Only in a farming population could contrasts between the disease ridden masses and a healthy, non-producing, elite develop. Skeletons from Greek tombs at Mycenae around 1500 BC suggest that royals enjoyed a better diet than commoners, since the royal skeletons were two or three inches taller and had better teeth (on the average, one instead of six cavities or missing teeth). Among mummies from Chilean cemeteries around 1000 AD, the elite were distinguished not only by ornaments and gold hairclips, but also by a four-fold lower rate of bone lesions stemming from infectious diseases.
These signs, of health differentials within local communities of farmers in the past appear on a global scale in the modern world. To most American and European readers, the argument that humanity could on the average be better off as hunter-gatherers than we are today sounds ridiculous, because most people in industrial societies today enjoy better health than most hunter-gatherers. However, Americans and Europeans are an elite in today's world, dependent on oil and other materials imported from countries with large peasant populations and much lower health standards. If you could choose between being a middle-class American, a Bushman hunter, and a peasant farmer in Ethiopia, the first choice would undoubtedly be the healthiest one, but the third choice might be the least healthy.
While giving rise to class divisions for the first time, farming may also have exacerbated sexual inequality already in existence. With the advent of agriculture, women often became beasts of burden, were drained by more frequent pregnancies (see below), and thus suffered poorer health. For example, among the 'Chilean mummies from 1000 AD, women exceeded men in osteoarthritis and in bone lesions from infectious diseases. In New Guinea farming communities today I often see women staggering under a load of vegetables and firewood while the men walk empty-handed. In one case I offered to pay some villagers to carry supplies from an airstrip to my mountain camp, and a group of men, women, and children volunteered. The heaviest item was a 110-pound bag of rice, which I lashed to a pole and assigned to a team of four men to shoulder the pole together. When I eventually caught up with the villagers, the men were carrying light loads, while one small woman weighing less than the bag of rice was bent under it, supporting its weight by a cord across her temples.
As for the claim that agriculture laid the foundations of art by providing us with leisure time, modern hunter-gatherers have on the average at least as much free time as do farmers. I grant that some people in industrial and farming societies enjoy more leisure than hunter-gatherers, at the expense of many others who support them and have far less leisure. Farming undoubtedly made it possible to sustain full-time craftsmen and artists, without whom we would not have such large-scale art projects as the Sistine Chapel and Cologne Cathedral. However, the whole emphasis on leisure time as a critical factor in explaining artistic differences among human societies seems to me misguided. It is not lack of time that prevents us today from surpassing the beauty of the Parthenon. While post-agricultural technological advances did make new art forms possible and art preservation easier, great paintings and sculptures on a smaller scale than that of Cologne Cathedral were already being produced by Cro-Magnon hunter-gatherers 15,000 years ago. Great art was still being produced in modern times by hunter-gatherers such as Eskimos and Pacific Northwest Indians. In addition, when we count up the specialists whom society became able to support after the advent of agriculture, we should recall not only Michelangelo and Shakespeare but also standing armies of professional killers.
Thus, with the advent of agriculture an elite became healthier, but many people became worse off. Instead of the progressivist party line that we chose agriculture because it was good for us, a cynic might ask how we got trapped by agriculture despite its being such a mixed blessing. The answer boils down to the adage, 'Might makes right. Farming could support far more people than hunting, whether or not it also brought on the average more food per mouth. (Population densities of hunter-gatherers are typically one person or less per square mile, while densities of farmers average at least ten times higher.) Partly, this is because an acre of field planted entirely in edible crops produces far more tons of food, and allows one to feed far more mouths, than an acre of forest with scattered edible wild plants. Partly, too, it is because nomadic hunter-gatherers have to keep their children spaced at four-year intervals by infanticide and other means, since a mother must carry her toddler until it is old enough to keep up with the adults. Because sedentary farmers do not have that problem, they can and do have a child every two years. Perhaps the main reason we find it so hard to shake off the traditional view that farming was unequivocally good for us is that there is no doubt that it meant more tons of food per acre. We forget that it also meant more mouths to feed, and that health and quality of life depend on the amount of food per mouth. As population densities of hunter-gatherers slowly rose at the end of the Ice Age, bands had to 'choose', whether consciously or unconsciously, between feeding more mouths by taking the first steps towards agriculture, or else finding ways to limit growth. Some bands adopted the former solution, unable to anticipate the evils of farming, and seduced by the transient abundance they enjoyed until population growth caught up with increased food production. Such bands outbred and then drove off or killed the bands that chose to remain hunter-gatherers, because ten malnourished farmers can still outfight one healthy hunter. It is not that hunter-gatherers abandoned their lifestyle, but that those sensible enough not to abandon it were forced out of all areas except ones that farmers did not want. Modern hunter-gatherers persisted only in scattered areas useless for agriculture, such as the Arctic, deserts, and some rainforests. At this point it is ironic to recall the common complaint that archaeology is an expensive luxury, concerned with the remote past, and offering no lessons of present relevance. Archaeologists studying the rise of farming have reconstructed for us a stage where we made one of the most crucial decisions in human history. Forced to choose between limiting population growth or trying to increase food production, we opted for the latter and ended up with starvation, warfare, and tyranny. The same choice faces us today, with the difference that we now can learn from the past.
Hunter-gatherers practised the most successful and long-persistent lifestyle in the career of our species. In contrast, we are still struggling with the problems into which we descended with agriculture, and it is unclear whether we can solve them. Suppose that an archaeologist who had visited us from outer space were trying to explain human history to his fellow spacelings. The visitor might illustrate the results of his digs by a twenty-four-hour clock on which one hour of clock-time represents 100,000 years of real past time. If the history of the human race began at midnight, then we would now be almost at the end of our first day. We lived as hunter-gatherers for nearly the whole of that day, from midnight through dawn, noon, and sunset. Finally, at 11:54 pm we adopted agriculture. In retrospect, the decision was inevitable, and there is now no question of turning back. But as our second midnight approaches, will the present plight of African peasants gradually spread to engulf all of us? Or, will we somehow achieve those seductive blessings that we imagine behind agriculture's glittering facade, and that have so far eluded us except in mixed form?