WATCH: Threshold 7 — Agriculture

NARRATOR: The last Ice Age ended a little over 10,000 years ago. At that point, human communities in different parts of the world began using a range of new technologies to increase the energy and resources they could extract from their environments. We call these new technologies agriculture, and its development is our seventh threshold. What ingredients led to this threshold? Well, first, thanks to collective learning, humans had accumulated vast knowledge about their environments over many generations. Second, by the end of the last Ice Age, humans had also settled all parts of the world. And some began to live in denser communities. Populations increased and some regions such as Mesopotamia began to have about as many people as foraging techniques could support. Now, more people meant you had to try to get more food from a given area. So some groups started using simple forms of irrigation, or they planted wheat, or they herded goats and cattle for their meat. These experiments were the beginning of agriculture. Global climates also got warmer and more stable than ever before. These conditions made it possible to plant and tend crops with some confidence that they would yield abundant harvests. Within a few generations, some plants and even some animals became domesticated, or more dependent on humans. And as animals became tastier or more nutritious or more docile, they became more attractive to farmers. Farming took off and began to spread around the world. Agriculture was really a way to increase the amount of the sun's energy that was used by our own species. So humans began changing the plants, the animals and the landscapes around them so that they could use more and more of the products of photosynthesis. This energy bonanza led to the creation of villages, of cities and of huge agrarian civilizations. Eventually, an even bigger energy bonanza would steer human history towards threshold number eight, the modern revolution.