Over the past millenniums, people have occasionally used fire, from about 800,000 years ago, homo erectus used it daily; there have been found ashes with thickness of many meters, meaning that some fires were never put out. Initially, they used it for warmth, lighting, and protection. Over the past 2 million years, although humans had created social structures, had learned to use tools and had superior thoughts from other animals, they remained at the bottom of food chain, used to be eaten by all animals with their size or bigger. With fire, they hardened the edge of pikes so they could hit big animals from afar, with controlled fires could drive an entire herd into a cliff; they were safe with the fire burning around their camp.
For thousands of years they had not imagined that fire could cook their food. At some point, some hungry people had nothing to eat but burned animals, so cooking was discovered. Cooked food has made digestion easier, and the energy saved by digestion was given to cerebral maturation. Generation after generation, the intestines diminished and the brain grew bigger. Potatoes, rice and wheat, which were not eatable before, became basic food. People's sociability soon changed as they sat around the fire to cook and eat, they were looking for ways to communicate. The first words, probably came out around a fire.
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