THE COMING OF FIRE:
The greatest of the cultural advances of Homo erectus was to learn to manage fire. The earliest evidence of its use comes from China (c. 6000,000BC) but it does not show that fire could be made. Probable Homo erectus never got so far. Still, that the species could make use of it was an enormous gain, the most important single change in technology before the coming of agriculture. It was the first chemical tapping of energy other than by the conversion of food inside the body.
Many peoples have had legends of heroic figures or magical beasts who first seized fire, often from the gods. Perhaps this reflects a dim memory that the first fire was taken from a natural source, whether from volcanic activity, an outbreak of natural gas, or a blazing forest. However it was obtained, the use of fire was revolutionary-though we must remember that it took hundreds of thousands of years to develop its full impact. Immediately, it meant warmth and light, the conquest of the cold and the dark and therefore the extension of the habitable environment into them, even if only a little way at first. Families could survive in colder regions than before, and could live in temperate zones with a little more ease. By occupying caves whose darkness had previously made them unusable, they were safer from the weather. Animals could now be driven out of their lairs and kept out (perhaps this is how the idea came of using fire to drive big game in hunting). Wooden spears could be hardened in fires. Cooking became possible. As a result, eating became easier; marrow can be sucked out of cooked bones but getting it out raw is a laborious business. Gibbons and gorillas have to spend much of their time simply chewing their raw food; cooking saved time, for food softened by it did not have to be chewed so long. Time was thus made available to do other things. More important still, substances indigestible in their raw state could become sources of food; distasteful or bitter plants could be made edible. This must have increased food supply (and therefore made population growth a little easier). It may also have stimulated attention to the variety and availability of plant life and so have launched the science of botany and the art of cookery. Finally, in the long run, eating cooked food helped to alter the shape of the face and the form of the teeth.
Cooking would have encouraged further restraint on immediate impulses, too: you put off eating and did not give way to immediate appetite by swallowing raw food. The focus of the cooking fire as a source of light and warmth would have brought people around it after dark and helped to make a group more aware of itself as a community. They would have talked somehow: the development of language-of whose origins we know little-must have speeded up in this setting. Finally, fire slowly brought new distinctions between members of the group. At some point fire bearers and fire specialists appeared, beings of awesome and mysterious importance, for on them might depend life and death for the rest of the group. They carried and guarded the great liberating tool, and controlled its power to break up the iron rigidity and discipline of night and day and even that of the seasons.
During the age of Homo erectus, then, fire had already a little offset the pressures of the great external rhythms of the natural world on hominid life. Life was already less dominated by routine and less automatic than it had been for Australopithecus; it was now far removed from that of animals merely programmed by instinct and genetic endowment. Homo erectus could make choices. This is the best ground for saying that with this species we are already on the human side of any definition of the difference between apes and men, however cramped and miserable its life may appear.
Roberts, A Short History of the World: pgs10-11.