agricultural revolution

The Seed of Civilization

When was the most important event in the history of mankind?

The answer is fuzzy, but for simplicity's sake, we can place it about 10,000 years ago. That was when humanity gave up its 2 million long history of roaming from place to place, hunting and gathering, and settled down to daily toil and daily bread. Naturally, I'm speaking about the agricultural revolution, and the amazing discovery of the seed.

People must have chewed nuts and grains for a while before they realised that if they put these into the earth, a new plant would spring from it. The discovery of that miracle must have been pretty startling in itself, but an even greater event was the impact it made on humanity. Pretty much everything in our society can be traced back (with some imagination) to the discovery of agriculture. Beer, bread, bazookas; you name it.

The Beginning

About 12,000 years ago, when the last Ice Age ended, humanity had spread to all corners of Earth. The pre-agricultural tribes went from camp to camp, depending on season. Many of them had begun to control the seeds, by deciding where they should grow, and later harvest them. However, since they didn't stay put in one place, there was a limit to how much work they could do. Slowly, things changed. Some people stopped shifting dwellings, instead they stayed in one place all year. We don't know why they did this - maybe the Earth had become overpopulated, and there just wasn't enough room for everyone to keep shifting home. Maybe climatic changes led to less food for them to hunt and gather. Or perhaps they just fancied a change.

A few societies remained in the Eden-like state of non-agriculture. These peoples live in fringe areas, areas with a climate too hot, too cold or too dry for growing things. The Inuit people of Greenland and Northern America are one example, the pygmies in Africa another, the Aboriginals in Australia a third.

In other places, they ended up with a lifestyle somewhere in between wandering indefinitely and settling permanently. In arid zones like the Sahara or Mongolia, people would start bringing animals with them on their wanderings - great herds of cattle, sheep, or whatever. This pastoralistic lifestyle creates a buffer for leaner times when the herders can live off their animals instead of starving, themselves.

In rain forest areas in, say, India and the Amazon, tribal communities have practiced slash and burn agriculture up to our days. This is a good way of living in places with little top-soil and heavy rains, but cannot support a large number of people.

However, the living solution that eventually came to dominate the globe involved settling down in one place and staying there, tilling the earth. Being sedentary has many advantages. For instance, you can store things. Surplus food can be stored for when it's needed, you don't need to lug it around. You can also make and keep more utensils and tools, not just the bare necessities. You can build nice, protective houses and walls.

You can also work complicated constructions to improve the farmland. These implements are our best proof of when and where human cultivation began getting serious. Another helpful tool is studying pollen levels in left in the soil from that period - this will show which plants flowered in an area at that time.

These are the current core areas scientists agree agriculture started before it spread outwards - all dates approximates, of course.

Growth leads to growth

A sedentary farming community grows much faster than a group of nomads. There are several reasons for this. First, women who breastfeed produce Prolactin, which works as a contraceptive, but only for a few hours after each feeding. Among nomads it seriously reduces the number of children born, because the mother carries and her baby at all times and feeds it regularly until it is a few years old. In a safe, fenced farming community children can be left alone at a younger age. They can also start eating adult food much earlier, because things like soup and porridge are easy to consume.

For travellers, survival of the fittest tends to mean that only people who are healthy are able to walk. Old and sick people are left behind. In a farming community, they can be cared for and given enough food without being too much of a burden. Having stores of food also prevents starvation, which helps keeping people resistant to disease.

The earth-workers had other problems in store, of course: Crops may fail, and then you have a huge problem. One or two types of food is not likely to give you all the substances you need in your diet, which the hunter-gatherers got from eating just about everything. People who live together permanently in large groups have a problem with sanitation, and are likely to fall victim of epidemics now and then. But despite these drawbacks, the world's human population began growing exponentially, a growth which still hasn't stopped.

At first, there were no great inventions to make life simpler for men and women who tended the fields. All they needed was the hoe, a simple tool that had been with them for a long time. Eventually, however, the ground was laid for new, revolutionary inventions: The plow, the wheel, writing, mathematics.

From small bands of people, humanity now found itself walled up in growing cities. Living at close quarters inevitably leads to tension, which leads to a need for rules of conduct. This is the seed to our modern laws as well as etiquette.

Being able to own more than you could carry changed a lot in the social order as well. Now wealth became the key to climb the social ladder, not strength or skill at hunting. Wealth, unlike physical abilities, can be hoarded and inherited. Social stratification, specialisation, and status symbols began developing.

Once you pop, you can't stop

As populations grew bigger, enough food had to be grown to feed them. And as more food was grown, populations grew even bigger. Agricultural methods became more sophisticated. Fields were drained and irrigated, soil turned and aerated. Meanwhile, society grew more complicated.

Private ownership inevitably leads to greed and envy. A new type of crime emerged - theft. It was strongly condemned, in fact universally scorned and punished, unlike murder, which could be allowed under certain circumstances. People who were not thieves had to establish guards and build strong walls to protect their food and goods - Jericho is the famous, first walled city that we know of.

More powerful thieves resorted to armed robbery, while the self-styled rightful owners of the lands started demanding taxes from the people who worked them. When yield from the fields grew, it was possible for a number of people to do other things. While farmers produced food for everyone, others became soldiers, administrators, artisans, artists, and priests.

The seed that changed humanity in turn became changed by humanity. Through artificial selection, humanity nurtured the plants that produced the most food for them, while making their best effort to destroy unproductive weeds. Their plants, in turn, became high yielders, but were less hardy than their wild relatives. This is even more obvious in domesticated animals, where all breeding can be controlled. In today's extreme cases, we have cows that can't walk and sheep that can't look after themselves. But their yield is fantastic.

The move that made humanity

The agricultural revolution was neither swift nor bloody. However, it was the most dramatic change in human history. We moved from small, carefree nomadic groups to civilizations that created pyramids, mass warfare, literature, and destroyed the environment in a big way.

Pretty much everything can be traced back to this revolution - at least with a little goodwill.

Did we win, or did we lose? The agricultural revolution enabled man to do great things and horrible things. We could not have led the life we do today if it hadn't been for the agricultural revolution. On the other hand, the pre-agrarian society was simpler than ours, usually much more peaceful, and with an easier workload. We live in a stressful world - but at the same time, we are able to know about and influence the world around us to a much higher degree than anyone living in harmony with nature.

AKA the Neolithic Revolution*

To start off, hunter-gatherers were not stupid; it is highly unlikely that humans did not know 'the secret of the seed' long before they started farming. No one knows exactly why they started farming, but it may have been due to population increase,** lack of wild edible foods, or just chance.

For whatever reason humans started doing it, they found that it was addictive. Farming allows for a larger population, in part because of the potential for increased food supply, and in part because you can have lots and lots of children. In hunter-gatherer populations you have to carry young children around with you, limiting your mobility. In farming societies you don't have this problem; in fact, on the farm children can be a benefit at around age five, helping out around the house (and, ironically, with child-care). It is also possible that lactation acts as a form of birth control; hunter-gatherers tend to breastfeed young children for the first couple years, because there isn't much else for them to eat. Farmers can often feed babies ground grain mush, freeing the mother from breastfeeding. This allows her to work on other tasks -- and perhaps makes her more fertile as a side effect.

A larger population may not have the option of going back to hunting-gathering, even if they wanted to, because the local ecosystem can't support the enlarged population without the added food gained from farming. To make matters worse, after a few generations people may start to forget the skills needed to survive as hunter-gatherers.

One cool side effect of settling down is the ability to own more stuff. Hunter-gatherers have to carry all of their possessions, and so make do with as little as possible. For example, pottery tends to come along with farming; this is probably not a coincidence. Pottery is a simple enough idea, but it is heavy. Farmers also own land. Hunter-gatherers sometimes own land, but it is not so common and is less enforced than it tends to be in farming societies.

Once you have the idea of land ownership and a growing population, farming takes off -- you start working more land, you have more children, they start working more land, etc. Farming has appeared independently in multiple areas -- Asia, Africa, and the Americas, perhaps multiple times in each of these areas. While it may be slow to spread in any given area, in the end it nearly always takes over.

Eventually you get all the trappings: governments, state societies, money, the working class and the nobility, etc. But long before you get to the level of modern day Europe and America, one fact stands out above all others: Farming stinks. The shift from hunting-gathering to agriculture has been called the greatest mistake the human race has ever made. Disease goes up, nutrition is degraded, death rates may hold steady in some cases, but it often sky-rockets. For example, all of Europe until the 1800s was pretty awful.

One problem with agriculture is that it limits the variety of foods available to a population. Foragers get food from many different plants and animals, and thus are more likely to get all of the vitamins and minerals that they need. Farming societies tend to have higher rates of goiter, pellagra, xerophthalmia, beriberi, tetany, rickets, anemia, and other deficiency diseases. Another problem is that crops will sometimes fail, and when they do, people die. Hunter-gather societies tend to have many food sources to fall back on; this is true even in 'modern day' (i.e. last 50 years) hunter-gatherer societies, which live in the most marginal environments there are (the Kalahari Desert, sub-Arctic Canada). When farming was just beginning, hunter-gatherers lived in many more friendly environments than they do now. We get another twist when trade networks pop up; there are many modern day examples of small farming populations trading nutritional foods needed for their good health to other populations in return for 'luxury' goods (or rent on their land, once real class societies get going).

This exacerbates another problem of farming societies: increased amounts of pathogenic diseases. Hunter-gatherer populations tend to leave their waste behind them when they move. Settled populations cannot do this. The waste tends to attract vermin (like rats and insects), which spread disease. Feces tend to carry parasites like tapeworm and hookworm (which in turn prevent humans from absorbing all the nutrients they need, and add to the deficiency diseases). This is often made worse when human waste is used as a fertilizer. With higher population concentrations, contagious diseases become a problem; in a large enough population, epidemic diseases can circulate. This doesn't happen in smaller populations, because after passing through a population once diseases like measles and smallpox leave all hosts dead or immune to re-infection. If a large number of new hosts aren't entering the population (usually thru new births), the disease will have no one to infect, and it will die out.

And there are yet more problems with agriculture-based societies: domesticated animals can act as reservoirs for disease, and sometimes diseases of these animals will pass over into humans (the pox viruses and influenza are believed to have originated in domestic animals); since there is usually less breastfeeding, babies are more likely to get sick; changes in the environment may cause diseases, for example clearing rain forests makes new opportunities for the malaria-carrying mosquitoes to breed; and because there are so many opportunities for disease any given individual may have a heavier burden (more parasites per person).

But even before modern medicine stepped in to save us, settled populations had some benefits, disease-wise. For example, settled populations are better able to take care of the sick, while hunter-gatherers travel around. The movement of hunter-gatherers may have exposed them to multiple cases of diseases, in slightly different localized variations (analogous to traveler's diarrhea). Settled populations may also have a better chance to develop commensal bacteria loads, which help protect them from some diseases, although this is in debate. Perhaps the most important effect of having a large settled population is that epidemics are very powerful weapons. If you have had an epidemic circulating through your population for a long time, most individuals will be immune to it (having had it once, probably while still young children). When you move into new areas, you bring the disease with you, killing large numbers of the unexposed populations. This was of great impact when Europeans came to the New World, and may have been significant on a smaller scale in the distant past. (This would probably not have been an issue until the event of state societies, because epidemics require 5,000 new individuals per year, at a low estimate, to propagate.)

At best, agriculture was a mixed blessing. For the past 10,000 years it has been making lives miserable. It was not until the last ~100 years that it paid off for large segments of any population. On the bright side, if the current trend continues, the next 10,000 years look like they'll be great.

* 'Neolithic revolution' is probably more accurate than 'agricultural revolution', because the agricultural revolution didn't start with agriculture, but with horticulture. Neolithic refers to stone age farmers who appeared here and there about 8,000 to 10,000 years ago. But this refers only to European cultures; in the Americas, farming started in the Archaic and early Woodland cultures, about 1,000 to 9,000 years ago. The Mississippian period is when farming really took off in the Americas, 1,000 years ago. So there is some justification for calling it the agricultural revolution, if you are talking about farming in all parts of the world.

** While population growth does come with farming, there is a long standing debate about which came first -- do you farm because you have too many people to feed by other means, or do you have so many people because you farm?

For much more, Health and the Rise of Civilization by Mark Nathan Cohen is a good, if long, book.