A revolution that took millennia
The “Agricultural Revolution” here means the Neolithic shift from gathering wild foods to growing crops and keeping animals. It is called a revolution because of its effects, not its speed. The change happened over thousands of years, and in some places people mixed foraging and farming for a long time. It is not the same as the later British farming changes of the 1700s that are sometimes given the same name.
Where and when
The best-studied early farming took place in the Fertile Crescent, an arc of land in the Middle East, starting roughly 10,000 to 11,000 years ago. People there cultivated wheat, barley, peas and lentils, and they kept sheep, goats, cattle and pigs. Farming also arose independently in several other places, with different crops:
- East Asia: rice in the south and millet further north.
- Mesoamerica: maize, squash and beans.
- The Andes: potatoes and, later, other root crops, along with llamas.
- New Guinea and parts of Africa and North America: other locally important plants.
Exact dates vary by region and are updated as archaeologists find new evidence. What stands out is how many separate societies reached similar solutions within what is a short span in the long history of our species.
Why farming began
Nobody knows for certain why people took it up. Ideas that scholars discuss include a warmer, more stable climate after the last of the ice ages, which may have made plants more dependable, as well as population pressure, shifting local resources, and the gradual building of knowledge about plants through repeated harvesting and planting. Many experts think it was a mixture of causes that differed from place to place. It was probably not a single decision, and the early farmers did not know where it would lead.
Domestication
Domestication is a slow, mutual process of change. People favored plants with larger seeds that stayed on the stalk, and animals that were calmer and easier to manage. Over generations, the plants and animals became genetically different from their wild relatives, and the people who depended on them changed their own way of life. Such changes help explain why the crops in a grocery store look so unlike their wild ancestors. Today’s precision farming and modern breeding programs are the latest stage in a very long relationship between people and plants.
Settlement and surplus
Farming ties people to land. Planting and harvesting require staying near fields, so villages became more permanent. Houses, storage pits and granaries appeared. Because farmland could generally feed more people than the same land used for foraging, populations tended to grow.
Surplus food had large social effects. If some grain could be stored, not everyone had to farm all the time. Some people could become potters, builders, priests, traders or soldiers. Storage also created things to manage and protect, which encouraged record keeping, and tied into the early writing systems that eventually arose. In several regions these trends led to cities and states, which is why farming is considered a foundation for many ancient civilizations.
Social structure
Settled farming plausibly increased inequality in many places. Land and stored food can be owned, inherited and defended in a way that wild foods usually cannot. Evidence from burials and house sizes in some early settlements points to growing differences in wealth over time, and leaders, chiefs and ruling families emerged in many societies. Scholars disagree about how fast this happened and how much it varied; some early farming communities appear to have been relatively egalitarian for long periods.
Work roles also changed. Farming often meant heavy, repetitive labor, and evidence from some sites suggests that women and men took on differing tasks, though patterns differ widely and the evidence is thin.
Costs to health and environment
Farming did not simply make life better. Skeletons from several early farming communities show signs of poorer nutrition than those of their forager neighbors, including shorter average height and more dental decay, probably because diets relied heavily on a few crops. Crowded villages and closeness to livestock made it easier for infections to spread, and many human diseases are thought to have started in animals. Understanding these patterns is part of understanding disease transmission across history.
Farming also changed landscapes. Clearing land, irrigating fields and grazing animals altered ecosystems and sometimes led to soil erosion or salty soil. These are early examples of what later became broader concerns about the human footprint on the environment.
Why it still matters
Almost every food system today descends from these changes. Societies still depend on a handful of staple crops, and problems like crop failure and food insecurity are reminders of how closely human life is tied to harvests. Even the shape of settlements, from villages to cities, grows out of the pattern of settling near fields. A long-view perspective, such as the one provided by the study of human origins, shows that for most of our species’ existence people were foragers, and that farming is a relatively recent chapter.
A note on uncertainty
Archaeology keeps revising the picture. New methods, such as analyzing ancient DNA and residues on pottery, regularly adjust dates and suggest new routes by which crops and animals spread. Readers should treat specific dates as approximate and expect them to change.