The Origins of Agriculture

The Big History of Civilizations

Explore the most important revolution in the history of humanity, and even of our planet: the transition from foraging to agriculture.

Anthropologists and archaeologists have struggled to answer the following three questions for more than a century: Why would humans give up foraging, a lifeway that had successfully sustained them for almost 200,000 years, and adopt agriculture? Did this happen all over the world at the same time, or did some humans in just a few places adopt farming and many others not? What has been the impact of the agricultural revolution on human lifeways and the biosphere?

The Shift to Agriculture

  • Around 12,000 years ago, humans were living on all of earth’s continents except Antarctica. Wherever they lived, humans survived through foraging, by using collective learning to invent a range of technologies perfectly adapted to different environments, from the icy world of the Arctic to the deserts of Australia.
  • Collective learning and technological innovation were going on, but the small size of human communities in the Old Stone Age, and the limited exchanges between them, meant that the pace of change had been slow for close to 200 millennia. But then something changed, and it changed quickly.
  • By 11,500 years ago, new subsistence technologies were beginning to appear in certain regions of the planet—technologies that, by enabling humans to cultivate their own sources of food, over time gave humans access to more energy and resources.
  • This meant that not only did human populations begin to increase globally, but in the new agricultural zones, humans were living in larger and denser concentrations in new types of communities, such as villages and towns.
  • Increased densities like this were frankly impossible during the Paleolithic, because foragers needed a huge range of territory to support themselves. But farming can support many more people in the same area.
  • Where agriculture was adopted, denser populations appeared and the pace of historical change began to speed up, putting humans onto a new historical pathway that led directly toward the astonishing world of complex states and civilizations.
  • But where foraging remained the dominant lifeway and populations remained small and scattered, change was slower. This meant that, for the first time in human history, the pace of change began to vary from region to region.
  • The transition to agriculture was thus of such profound significance that it marks the crossing of another threshold of complexity by our species—and indeed by planet earth.
  • The timing of the transition was critical: Agriculture was adopted early in parts of Afro-Eurasia, much later in the Americas and the Pacific, and hardly at all in most of Australasia, and this had significant implications for the appearance of civilizations.

Foraging versus Farming

  • To understand why and where agriculture appeared when it did, let’s consider how foraging and farming differ.
  • Foragers are very good at finding new sources of energy by spreading into new environmental niches, a process called In contrast, farmers largely stay in one place, so they have to find ways to extract more energy from the area of land they have available, a process called intensification.
  • Foragers live off a wide variety of animal and plant species that are products of natural selection. Farmers, on the other hand, depend on a much smaller number of species and have learned to increase their output through artificial selection.
  • Successful farming also depends on the establishment of a strong relationship between plants, animals, and the human farmer, an interaction that evolves into a form of symbiosis, or species codependence. Symbiosis is common in the natural world, where different species have evolved to rely on each other for food or protection, often becoming so dependent that they can no longer survive alone.
  • Humans have learned over the course of 11,000 years to herd and manipulate useful species, such as corn and cattle, and how to increase production of our “domesticates” to support more of our own species. Humans benefit from this symbiotic relationship, but so do our domesticated species, which we protect from predators and help reproduce, ensuring their success as a species.
  • Note, though, that the impact of this relationship has been different for each partner. Humans have changed culturally because of domestication, leading to the invention of new technologies and lifeways and the evolution of our communities from small foraging bands to complex, interdependent cities, states, and civilizations. Our domesticates have changed genetically, often evolving into an entirely new species.

The Origins of Agriculture

  • It appears that the transition to agriculture was not an abrupt change; the road from gathering plants in the wild, then cultivating and finally domesticating them, was long and convoluted.
  • Geneticists working on plant genomes have been crucial in unlocking the nuances of this transition, as they look for genetic evidence of physical changes in species as a product of domestication. Plant genomes show us that humans were harvesting and eating wild cereals for thousands of years before actual domestication began.
  • The earliest sites and dates for actual species domestication are difficult to determine. But there is little doubt that the first successful attempt at domesticating a species was undertaken by Paleolithic foragers, and that was the domestication of the dog. The oldest actual remains of a domesticated dog have been dated to around 15,000 years ago.
  • The domestication of other species by early farmers occurred gradually around the world over long time periods. This began in Southwest Asia around 11,500 years ago, then in northeast Africa perhaps a thousand years later, in East Asia at least 9,000 years ago, and eventually in New Guinea, sub-Saharan Africa, South Asia, and the Americas in the millennia that followed.
  • The agricultural revolution can be explained as a step-by-step process in which conscious human decision making may have played only a limited role. Critical to the “evolutionary not revolutionary” model is climate change and the emergence of environmental conditions that facilitated the transition, coupled with demographic pressure as a result of increasing population densities in some regions.
  • The last cycle of the most recent ice age began around 110,000 years ago, and global temperatures plunged to their coldest level between 21,000 and 17,000 years ago. Conditions were so cold that forest disappeared and frigid tundra covered much of the planet.
  • Under these conditions, foraging was the only survival strategy possible for humans, and this remained the situation until the beginning of the Holocene epoch around 11,700 years ago, when the earth experienced a rapid global warming at the end of the last ice age.
  • The Holocene was not only warmer and wetter, but also more climatically stable, and as different groups experimented with domestication, they increased in size relative to foraging bands. Researcher Peter Richerson argues that this increase in group size led to intergroup competition, and this more or less forced communities to adopt farming.
  • Building on the work of Richerson and other specialists, big history offers a five-step model to try to explain the origins of agriculture.
    1. Humans already had a lot of the necessary knowledge and skills for farming. For almost 200,000 years, humans had been endlessly manipulating other species and landscapes to enhance our food supply and reduce our exposure to predators. So, our foraging ancestors were already preadapted culturally to manipulate the natural environment.
    2. Some animal and plant species were also essentially preadapted as potential domesticates. This means that some animals and plants had evolved in a way that made them more suitable for domestication than others. Potential animal domesticates have to meet some demanding criteria, including rapid growth, regular birth rates, a herd mentality, and a good disposition.
    3. Humans in certain key regions of the globe were already adopting less nomadic lifestyles and becoming at least part-time sedentary. Sedentism began to increase in some parts of the world from about 11,000 years ago. The two main reasons for this were climate change and population pressure. As climates became warmer and wetter at the end of the last ice age, in some areas there appeared regions of natural abundance, where large numbers of humans settled, and increased sedentism eventually led to overpopulation.
    4. Because of affluent foraging, population pressures resulting from sedentism and continuing migration forced human communities into smaller and smaller territories. By 13,000 Before Present, foragers were occupying a wide range of environmental niches all over the planet, and in some cases these niches could not support increased populations. These groups were forced to try to feed themselves off rapidly diminishing parcels of land, and with further migration not really an option, they found themselves caught in the “trap of sedentism.”
    5. Faced with increasing populations, many communities were left with few alternative survival strategies. Because of continuing climate change and the resulting lack of space, a return to a nomadic, foraging lifeway was impossible. The only viable option available for affluent foragers faced with overpopulation pressure and climate change was to intensify cultivation and adopt farming. And that’s exactly what appears to have happened at sites that could support large populations.

Questions to Consider

  • Why do big historians view the transition to agriculture as perhaps the most important revolution in all of human history?
  • Does the five-step model explain the appearance of agriculture in all regions?
From the lecture series:  The Big History of Civilizations
Taught by Professor Craig G. Benjamin, Ph.D., Grand Valley State University