A significant step on the road to the top of the food chain was the domestication of fire.
It is possible that some human species have occasionally used fire since 800,000 years ago .
But 400,000 years ago Homo Erectus , the Neanderthal and the ancestors of Homo Sapiens used fire on a daily basis.
Humans now had a formidable source of light and heat, as well as a deadly weapon against predatory lions.
Not long after, the humans must have started deliberately setting fire to their neighborhoods.
A carefully managed fire could transform stretches of impenetrable scrub into spaces where tall grass would grow and populate with game.
In addition, once the fire was out, the enterprising spirits of the Stone Age could walk through the smoking remains and harvest toasted animals, nuts and tubers .
However, the best thing that was done with fire was cooking.
Foods that humans could not digest in their natural forms - such as wheat, rice and potatoes - became basics of our diet thanks to cooking. Fire not only changed the chemistry of food, it also changed biology.
Cooking meant killing the germs and parasites that infested the food. It was also easier to chew and digest, once cooked, the dear old foods of before, such as fruits, nuts, insects and even carrion.
While chimpanzees spent five hours a day chewing raw food, those who ate cooked food only needed one hour.
The advent of cooking allowed humans to eat a greater diversity of foods, spend less time eating and get by with smaller teeth and shorter intestines.
Some scholars believe that there is a direct link between the advent of cooking food, the shortening of the intestinal tract and the growth of the human brain. Since long intestines and large brains are both strong energy consumers, it is a little difficult to have both.
By shortening the intestines and decreasing their energy consumption, cooking unintentionally paved the way for the large brains of the Neanderthal and the Sapiens .
The use of fire also marked the first great separation between man and other animals.
The power of almost all animals depends on their bodies:on the strength of their muscles, on the size of their teeth, on the spread of their wings.
Although they are able to exploit winds and currents, they are not able to control these natural forces and always remain conditioned by their physical model.
Eagles, for example, can identify the thermal columns of hot air that make them rise high. However, they are unable to control the location of such columns, and their maximum carrying capacity is strictly proportional to their wingspan.
By taming fire, humans gained control of a totally manageable and potentially limitless force. .
Unlike eagles, humans could decide when and where to light the flame, and were able to harness the fire for a number of needs.
Most important of all, the power of the fire was not conditioned by the shape, structure or strength of the human body.
A simple woman with a spark or a burning ember could ignite a entire forest in a matter of hours.
Neanderthal man was more ingenious than expected to start the fire.
He probably used a chemical, manganese dioxide , with which he 'treated' the wood to make combustion easier. The archaeologists of the Dutch university of Leiden are convinced of this , coordinated by Peter Heyes , which explain their hypothesis in the journal Scientific Reports .
According to the researchers the Neanderthal instead of exploiting the flames produced naturally by rubbing or forest fires, they resorted to another system. On the Pech-de-l'Azè site I in southwestern France, dating back 50,000 years ago , blocks of manganese dioxide have been found, which abounds in the regions of limestone formation.
Until now it was thought that the Neanderthals they used this element as a pigment to decorate their bodies with black, but according to Dutch researchers, charcoal and soot from bonfires were easier to make than body pigment. In addition, the Neanderthals of Pech-de-l'Azè I seem to have a clear preference for mangagnese dioxide which, compared to other manganese oxides available in their environment, is able to light a fire.
After noticing the abrasions on some stone blocks, the researchers ground some of them to obtain a powder, which sprinkled on a pile of wood, lowered the temperature necessary to start the combustion to 250 degrees, making it easier to ignition of the fire. Wood not 'treated' with manganese dioxide, on the other hand, failed to catch fire even at 350 degrees. It is not excluded, concludes the study, that the Neanderthalians also used this substance to paint their bodies, but based on their experiment they are convinced that it was also used to light the fire.