Why did ancient people switch to agriculture?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

The new work sheds light on a long-standing mystery: why did man invent agriculture, the basis of his civilization? Initially, there were no advantages in agriculture, but there were many disadvantages. It is also unclear why the transition was made only ten thousand years ago, although our species has existed for a third of a million years. The answer may be unexpected: it seems that earlier the very emergence of our civilization was impossible due to the different composition of the atmosphere of the ancient Earth. Let's try to figure out what exactly allowed humanity to become civilized.

Humans have hunted and gatherers since the inception of the genus Homo - more than two million years. It was a good and practical way to survive. Let's take a look at the bones of our ancestors who lived on the Russian Plain two tens of thousands of years ago: they have very strong bones, on which there are traces of excellent muscle relief.

All reconstructions say that the Paleolithic European, in terms of muscle strength and bone strength, was at the level of a modern professional athlete - and not a chess player. Along the way, he had 5-10% more brain volume than our average contemporary. And anthropologists tend to see the reason in the fact that he used this head more actively (due to the lack of specialization).

It follows from all this that the average Cro-Magnon was well fed. Olympic-grade bones and muscles will not appear without sufficient food. The brain requires up to 20% of all the energy consumed by the body, that is, if you use it, it devours it per unit of weight even more readily than muscles.

The fact that food was enough for our ancestors 20-30 thousand years ago - despite the severe ice age - is evident from the archaeological data. People fed their dogs venison, while they themselves preferred mammoth meat. Those who displayed such selectivity in their choice of meat were clearly not starving.

To work more, to eat less: what was the cunning plan of the first farmers?

But as soon as people switched to agriculture, problems began - and serious ones. The bones of the first farmers bear traces of rickets, an extremely unpleasant disease caused by poor nutrition and leading to curvature of the bones of the limbs and chest, as well as a whole bunch of further problems.

Skeleton of a child suffering from rickets, sketch, 19th century / © Wikimedia Commons

Growth falls sharply: the Paleolithic European male (before farming) was about 1.69 meters tall (average weight 67 kilograms), Neolithic (after) - just 1.66 meters (average weight 62 kilograms). The average height of a man in Europe returned to the level of the end of the ice age only in the 20th century, after 15 thousand years. Previously, the quality of food simply did not allow this. The muscle relief becomes worse, and the average volume of the brain gradually decreases.

By the way, modern ethnographic observations show the same thing: wherever in new and modern times people move from hunting and gathering to agriculture, their growth decreases, and their health deteriorates.

Why? The answer is quite obvious: the first farmers did not appear where the cultivation of cultivated plants gives the maximum yield, but where, to be honest, the productivity of the oldest species of cultivated plants is low. The highest yield is obtained from banana (more than 200 centners per hectare), cassava (cassava, also up to 200 centners per hectare), corn (depending on the variety and climate - more than 50 centners). Tarot has similar indicators.

But the first farmers did not have a modern banana and other things. And there was nothing out of date: they lived in the Middle East, where cereals were grown, or in the Far East, where, again, cereals were grown, only others (rice). In the first centuries of cultivation, their yields were ridiculously low: often a few centners per hectare (if you subtract the seed). To live from this, one person needs at least a hectare, and work on it will have to be very intensive.

Therefore, according to the calculations of scientists, even if we leave aside hunting and imagine a pre-agricultural culture living by gathering alone, then the return on one invested calorie in the collection of wild plants will be higher than with the deliberate cultivation of the same plants.

Yes, the yield per unit area will be lower, but primitive people did not have a problem of lack of areas: the population of the planet was negligible. But the fact that there was no need to dig the earth seriously saved energy, therefore, in terms of time and effort, gathering was more efficient than early farming.

Even today, when farmers have at their service crops long ago bred by breeders of the past, their cultivation - without the introduction of mineral fertilizers and the use of agricultural machinery - remains an extremely unproductive occupation. The Aeta people live in the Philippines, some of whom are farmers, and some are gatherers and hunters.

So, according to the latest data, farmers work 30 hours a week, but their non-agricultural counterparts - only 20 hours. Material wealth and the number of calories consumed in both groups are practically indistinguishable (however, the ratio of proteins and carbohydrates is different: the former's farmers have less, and the latter more).

And this is the picture for men, for women it is even worse. The fact is that before the transition to agriculture, women had no sense at all in hard work. It is much more difficult for them to kill the beast than for men, and it is even more difficult for them to defend their prey from other contenders such as huge (more modern) wolves, lions, hyenas and similar animals. Therefore, they simply did not participate in the hunt, and gathering could not take much time for the simple reason that the basis of the hunter's diet is animal food, not plant food.

The transition to agriculture dramatically changed the balance of efforts: working with a digging stick is quite within the power of a woman (the familiar patriarchal model of a family with a plowman man appears very late, after the spread of draft animals, and not on all continents). Let's go back to the same aeta. If their men had free daylight hours a week when switching to agriculture, instead of 40 hours, it became 30, then aeta women now have only 20 instead of almost 40 hours.

One of the authors of the work on aeta Abigail Page asks the question: "Why did people agree to the transition to agriculture at all?" The answer to it is, in fact, very difficult. This is only among the classics of Marxism-Leninism, not one of whom himself had a digging stick in his hands, which, by definition, produces an economy more efficiently than appropriating. And in life, as we found out above, everything was not at all like that. So what's the deal?

"We've killed everyone, it's time to switch to plant foods."

The first hypothesis that tries to explain this rests on the fact that, for some reason, there were fewer animals around that could be hunted. Either the melting of the glaciers, or the excessive hunting of the ancient people themselves led to their death, which is why they had to switch to agriculture - there was a banal lack of meat. This hypothesis has bottlenecks, and there are many.

A rather naive image of a mammoth hunt / © Wikimedia Commons

First, climate warming is usually accompanied by an increase in the biomass of animals per square kilometer. In typical tropics, the biomass of terrestrial mammals per square kilometer is several times and tens of times higher than in the tundra or taiga. Why are there tropics: on the Chinese side of the Amur, in Manchuria, tigers per square kilometer are several times higher than on the Russian side.

And tigers can be understood: in Russia they have trite less food, especially in winter. In Blagoveshchensk, for example, the average annual temperature is plus 1, 6 (not much higher than Murmansk), and the nearby Chinese Tsitsikar - plus 3, 5, which is already better than Vologda. Naturally, there are many more herbivores on the Chinese bank of the river, and even those tigers that live in Russia in summer (and are listed in our reserves) go south in winter, because they have to live somehow.

Secondly, it is doubtful that the ancient people took and mowed down all those animals that they could hunt during the ice age. How? Man was then a part of nature in the literal sense of the word: if he knocked out too many animals in one place, then he had to go where there was still prey, or starve. But hungry people naturally have low fertility and low child survival.

This is one of the reasons why Africans have been living on the same land for hundreds of thousands of years with elephants, buffaloes, rhinos and other large animals, but cannot destroy them. Why could primitive hunters, obviously worse armed in comparison with African hunters of recent centuries (who already have steel spearheads), have knocked out megafauna, but African hunters not?

A society where there is no property, no future

There are so many weak points in the "just ran out of meat" hypothesis that we will not even continue. Better to turn to the second theory, whose name is "property". Its supporters - for example, Samuel Bowles - argue that the transition to agriculture took place because people were sorry to leave their acquired property.

The first centers of the emergence of civilization were located near places rich in animals and wild plants and accumulated significant reserves in buildings resembling small barns. Once animals began to appear in this place less than usual, and people had a choice: to abandon pantries with supplies and look for an animal in the distance, or to start sowing, since observing the plants from the gatherers allowed this.

As agricultural civilizations developed, their pantries expanded. The foundation of this granary of the Harappan civilization measures 45 by 45 meters / © harappa.com

This hypothesis looks more robust, but there is a problem: it is untestable. We do not know how it actually happened, because little is said about the behavior of people of 10-12 thousand years in the sources.

However, there are also ideas in science that make it possible in theory to check exactly how such a transition could have taken place - on the basis of ethnographic observations of the last 100 years. They do not support the property hypothesis, but there are traces that indicate completely different roots of agriculture - and our civilization as a whole.

"Be Cool": Civilization Arose for Irrational Reasons?

Early farming did indeed require more labor and less return than gathering. But it becomes much more real to preserve the acquired by this labor. The meat can be dried, it can be salted, but also dried and salted meat tastes worse than recently mined, and it also practically does not contain vitamins (those in it disintegrate over time).

Grains of rice or wheat in the simplest vessels can be stored for years, and this was reliably done already in antiquity. The earliest known farming towns contain grain storage facilities. This means that the farmer can save. The question is, why? He can't eat more than he has, right?

In theory, yes. But a person is so arranged that the key motives of his behavior - even if it seems to him to be quite rational - in fact, are irrational and not under the direct control of reason.

Let's go back to the numbers above: Aeta farmers work by the sweat of their brows 30 hours a week, hunter-gatherers work 20 hours without stress, but how long do we work? Many - as much as 40 hours a week. And this is despite the fact that labor productivity in our country is higher than in aeta society. Unsurprisingly, a number of studies claim that those who practice primitive agriculture are more satisfied with their lives than residents of the modern metropolis. And those who have not yet switched to agriculture - even higher.

People of the Aeta people, drawing from 1885 / © Wikimedia Commons

The correct question will not sound like Abigail's (“Why did people generally agree to the transition to agriculture?”), But, for example, like this: “Why do people, instead of 20 hours of primitive hunter-gatherers agree to work 30 hours as farmers, then and for 40 hours, how are residents of big cities today?"

One of the most likely answers to this question is this: humans are a species of primate, a species of social. It is customary for us to pay great attention to social positioning. A person spends a significant part of his life doing what proves to others that he is stronger, more generous, smarter than the "average". A young primitive hunter who brings prey more often will be more attractive to girls or, for example, feel better compared to other men. He may never even be aware of this in all its clarity, but in reality, comparing himself and others in his social group will constantly have a large and - often - defining influence on his behavior.

Now the question is "What is the best way to prove yourself in social positioning?" solved very simply. Newer iPhone instead of Huawei, Tesla Model 3 instead of Nissan Leaf - in modern society, the means to show "I'm cooler" are presented in an extremely wide range, for every taste and wallet.

Let's quickly rewind tens of thousands of years ago. What do we have to choose from? Any normal man beats a mammoth, moreover, it is often a group case, it is not always possible to stand out. Going to get a bearskin, thereby showing frostbitten courage without much practical benefit? Young people of that era did this too - but at the same time it was possible to die naturally (such cases are known to archeology).

In general, the situation is difficult: neither iPhones, nor electric cars, but to show that you are cooler than others, or it is super difficult (if you decide to compete in painting with the only painter of the tribe), or both super difficult and dangerous - if, for example, get the skin of a bear and others prizes for not only everyone.

What is left? Improve the physical characteristics and skills of the hunter? But this is essentially an advanced and challenging sport. And in any sport, sooner or later, a person has a ceiling, beyond which it is necessary to train extremely intensively, and we are lazy.

Individual citizens have thrown themselves into inventions and fine arts. A certain Denisovite, for example, invented a high-speed drilling machine and, about 50 thousand years ago, made a piece of jewelry on it, which even today would not be ashamed of any jeweler with modern equipment. But, again, this is talent, and not everyone has talent - in contrast to the need for social positioning that everyone has, even if he consciously knows nothing about it.

A fragment of an ancient bracelet (on the left, below under artificial light it appears black, above it is dark green, as it seems in the open sun). The whole version of the bracelet had a hole in the center, through which a cord was threaded to fasten a small stone ring / © altai3d.ru

According to the supporters of the third hypothesis about the reasons for the transition to agriculture, the possibility of accumulation literally turned the ancient world upside down ten to twelve thousand years ago. Now it was possible not to rest 40 hours a week, but instead to work hard, saving up supplies that I personally couldn't eat much. Then, on their basis, feasts are arranged for fellow tribesmen - either with agricultural products, or, if there are pets in excess and there are pets ready to eat too much, using the meat of domestic animals.

So agriculture became the center of the whole social system of "big men" - influential people who often do not have a hereditary status, but strengthen their position in society by gifts to certain people, who in return feel a sense of duty to the "big man" and often become his supporters.

In New Guinea, at the center of such a system was moka, the custom of exchanging gifts of pigs. The one who brought more pigs with more weight had a higher social status. As a result, the accumulation of "surplus product" - the kind that the "big man" does not seem to need - has become an advanced means of social positioning. Ethnographers refer to such systems as "prestige economies" or "prestigious economies".

Following this, other aspects of the life of a civilized society began to catch up. Granaries and livestock must be protected. In this case, they build walls (Jericho), behind which there are dwellings and barns and behind which you can drive cattle. "Big men" soon begin to desire not only social weight, but also visible signs of their status - and order artisans more and more expensive jewelry. Then they begin to give grain already in debt to the one who needed it, receiving in his person a dependent person and … voila! We have societies like the ancient Mesopotamia, closer to the era of Hammurabi.

Why was farming so late?

Until recently, anthropologists tried to say that reliably a person of the modern type has existed for 40 thousand years, and earlier finds are some kind of "subspecies". But scientifically rigorous criteria for such subspecies are not and, apparently, will not be - which is also confirmed by paleogenetic data. Therefore, today in anthropology more and more people say directly: there was no Heidelberg and Neanderthal man, but there was an early and late Neanderthal, and genetically they are "seamless" - one species. In the same way, there is no "idaltu man" and "modern appearance": people who lived 0.33 million years in Morocco and today are one species.

This recognition, for all its scientific correctness, gave rise to a problem. If we humans have existed for at least a third of a million years, and the Neanderthals have existed even longer, then why did we switch to agriculture so late, which gave birth to our civilization? Why did we waste so long time hunting and gathering - albeit easy, but like any easy way, which did not allow us to "grow above ourselves" for hundreds of thousands of years in a row?

This seems to be the point that modern science has been able to understand most fully. An interesting experiment is described in Quaternary Science Reviews. The researchers took the South African endemic goat sour cherry and looked at what the plant's edible weight would be at different levels of CO2: 227, 285, 320 and 390 ppm. All of these levels are below modern (410 ppm). 320 roughly corresponds to the middle of the 20th century, 285 is roughly equal to pre-industrial (before 1750), and 227 is not much higher than 180 parts per million - this is how much carbon dioxide was in the air during the ice age.

The underground part of the goat sour cherry is the most energetically valuable. Its tubers have been eaten by South African gatherers from ancient times to the present day. With CO2 concentration as in the Ice Age, these tubers grow five times less than at the current CO2 level and a couple of times less than at the pre-industrial level of carbon dioxide in the air / © Wikimedia Commons

It turned out that at 227 parts per million, the mass of the edible parts of this plant, which played an important role in the life of the South African tribes of gatherers and hunters, was 80% less than at 390 parts per million. The experiments involved local women from the gatherer tribes. It was found that the extraction of edible human biomass of these plants with a value of 2,000 calories, naturally, takes different time depending on the level of CO2 they were grown at.

With the current concentration of carbon dioxide, it took the least time to harvest enough biomass to produce 2,000 calories. But at a level close to the ice age, it is twice as long. At the pre-industrial level, CO2 is almost one and a half times less than at the level of the ice ages. The authors emphasize that similar results should be observed for virtually all plants of the C3 type - that is, for virtually all major cereals on which the current human civilization has historically grown.

Three colors show the water regimes for the four main agricultural crops of antiquity in a series of laboratory experiments. Brown shows experiments where they received little water, green, which is more, blue - which is a lot. Vertical: biomass of these crops. Left - CO2 levels from the Ice Age. In the center - approximately the current one. Right - 750 parts per million, such was the last time tens of millions of years ago. It is easy to see that the biomass at the "glacial" level of CO2 is so small that it objectively makes no sense to engage in agriculture / © Wikimedia Commons

What does all this mean? At the beginning of our text, we explained: hunters and gatherers had a lot of free time - fortunately, they worked half the size of us, modern people in industrial societies. Therefore, they could spend it on experiments with early agriculture, the accumulation of the resulting product, which they could not eat themselves, but could distribute it when organizing a feast for the sake of raising social status.

But even with such an excess of time, which modern people do not have, hunter-gatherers could not switch to agriculture as the basis of their economy if it required more than one and a half times more labor costs than in the real history of people at the beginning of the Holocene. Because if the growth of the first farmers fell sharply, it means that agriculture deprived them of calories and proteins.

With its efficiency reduced by half, even such a great force as the desire for beneficial social positioning could not make people rush to plow and sow. For the simple reason that in the "low-carbon" air of the Ice Age - even on the warm equator - pure agriculture could bring its followers to real death from hunger.

Volcanic CO2 rises from the seabed. The higher the temperature of the water, the less carbon dioxide it can hold in the form of bubbles. Therefore, the end of the last glaciation sharply raised the level of CO2 in the atmosphere and made agriculture at least minimally meaningful / © Pasquale Vassallo, Stazione Zoologica, Anton Dohrn

From this, a number of authors conclude that the very fact of the transition to agriculture became possible only and exclusively as a result of an increase in the content of CO2 in the air from 180 to 240 (at the beginning) and 280 (subsequently) parts per million. The growth that has happened due to global warming since the end of the last ice age. As you know, with an increase in water temperature, the solubility of gases in it decreases - and carbon dioxide from the ocean entered the atmosphere, increasing its concentration in it.

That is, humanity physically could not switch to agriculture earlier than after the end of the ice age. And if it did it in the past interglacials - for example, Mikulinskoe, 120-110 thousand years ago - then later it had to give up this habit, since it would be difficult to survive with it after the onset of a new ice age.

The ice age ended 15 thousand years ago, and temperatures reached the present no earlier than 10-12 thousand years ago. However, temperatures here are still of secondary importance: even in the tropics with 180 parts of CO2 per million, farming did not make much sense / © SV

All this creates a funny situation. It turns out that modern human civilization has not only increased the content of carbon dioxide in the atmosphere to levels of a million years ago, but it would have been impossible without raising this level from its glacial minima. Perhaps the Anthropocene should be called the Carbonocene? After all, the anthropogenic influence on the planet could not have reached the current level without civilization, and it might not have arisen without a surge in the level of CO2 in the Earth's atmosphere.