Farming was probably the most important human invention. Before farming, people were much like other animals. They hunted and collected wild fruits and leaves to eat. Farming probably started as early as 12,000 years ago in the eastern Mediterranean area. People realised that they could grow what they wanted to eat in fields which they could plough and then sow with seeds they'd collected from the plants they liked best. These first farmers meant that other people were freed from looking for food all the time. They could do different things like live in the first cities and specialise in other crafts or trades: making pots, shoes or bricks for building.

So far as we other animals were concerned, this was the start of a major disaster. Because farming was so successful, many more people could survive and populations increased – which meant that more land was needed for growing more food. Today, almost all the farmable land on the planet has now been taken by humans. The forests that once grew on most of the land, together with all the animals that lived in them, have been destroyed by being burned or cut down. This is still happening in the areas where there still are forests – like the Amazon.