2. Investigating the why of the commerce, by starting from a plausible primordial world model.

4. Introduction Whereas in the animal world the apportionment of the resources, the food, follows hierarchical rules or is based upon winning a fight, human developed the habit to trade. This research is based on the investigation about a possible economical reason for the emergence of the commerce. The basic idea is that exchanging goods may be a more efficient way to share them than fighting: by trading the whole population may earn more and reach a major development.

5. 1 - The world In a primordial landscape a bunch of cavemen are walking around, looking for food. In this world each guy is alone and have to be self sufficient. The trees offer a wide range of fruits and lot of animals jump on the grasses, but no way to preserve the food are known: every day cavemen have to walk for miles to find what they need. May be not enough food would have been collected, so the risk to starve is the real life partner of those primitive men.

6. 2 - The Health To be healthy the cavemen have to eat both: fruits and meat. Eating a huge quantity of meat without eating fruit gives poor energy, as well as an only fruit based diet. The poorer is the diet, the weaker become the guy and a weak guy has few possibilities to survive and breed in this wild world. It is very important to find the right quantity of meat and fruit each day. Meeting another caveman offers the possibility to fight and steal her food, or to exchange extra food of a type to obtain some of the other type.

7. 3 - Birth and Die The human fertility is very high, every time a woman run across a man, even if they are never met in the past, they try to have a baby. The healthy the mother is the higher is the possibility of birth. A single woman may have several baby at a time, each of them inherits randomly the behaviour of one of the parents. The average life is very short: after few years the probability to die rise dramatically.

8. 4 - Meeting another caveman Every time a caveman meets a fellow man, her behaviour may be: Fighting in order to steal the food the opponent have not yet eaten. Trying to exchange fruit versus meat or vice versa, depending on the quantity each of the two guys is bringing.

9. 5 - Results of the simulation During the simulations the traders always tended to overcome the fighters, it seem to be plausible saying that "trading is more economical efficient than fighting". Even if, the simulation was started with a strong prevalence of fighters, for instance 80%, the evolution leads to a traders based population. The more the fighters were the faster they tend to fade: probably they tended to fight among they selves till become very weak.

10. Starting with 0,5 Traders vs 0,5 Fighters

11. Starting with 0,3 Traders vs 0,7 Fighters

12. Starting with 0,2 Traders vs 0,8 Fighters

13. 6 - Economical meaning The winner of a fight is always the more healthy, she picks up all the food the looser owns and runs away. The winner is the unique that takes advantages from the fight. By trading both the caveman may reach a profit: each of them by exchanging the exceeding food, fruit or meat, versus the insufficient one, meat or fruit. If both had the same food exceeding no exchanging would be done. Trading seems to fit better than fighting with the paradigm of the Nash's equilibrium.

14. The average health of the population rises when the number of fighters falls down.

15. 9 - Further works The model will constitute the starting framework to be used to simulate other human abilities as: socialisation, workers specialisation, institution emergence and so on. This early version of the F&M model will be implemented by adding elements devoted to increase the plausibility of the simulation as: humans partnership, family bounding, clan ownership and similar. To allow agents to evolve their behaviour either ANNs and GAs will be employed.