Jason Shogren, of the University of Wyoming, and his colleagues suggest that trade and specialisation are the reasons Homo sapiens displaced previous members of the genus, such as Homo neanderthalensis (Neanderthal man), and emerged triumphant as the only species of humanity.

One thing Homo sapiens does that Homo neanderthalensis shows no sign of having done is trade. The evidence suggests that such trade was going on even 40,000 years ago. Stone tools made of non-local materials, and sea-shell jewellery found far from the coast, are witnesses to long-distance exchanges. That Homo sapiens also practised division of labour and specialisation is suggested not only by the skilled nature of his craft work, but also by the fact that his dwellings had spaces apparently set aside for different uses.

To see if trade might be enough to account for the dominance of Homo sapiens, Dr Shogren and his colleagues created a computer model of population growth that attempts to capture the relevant variables for each species. These include fertility, mortality rates, hunting efficiency and the number of skilled and unskilled hunters in each group, as well as levels of skill in making objects such as weapons, and the ability to specialise and trade. . .

. . .they assumed that the most efficient human hunters specialised in hunting, while bad hunters hung up their spears and made things such as clothes and tools instead. Hunters and craftsmen then traded with one another.

According to the model, this arrangement resulted in everyone getting more meat, which drove up fertility and thus increased the population. Since the supply of meat was finite, that left less for Neanderthals, and their population declined.

I suspect, in light of the work of Surowiecki, Page and Lu Hong that this is too simplistic and misses some of the most powerful problem solving methods.

Specialization is an obvious as well as necessary behavior since humans seek to differentiate themselves to gain status and mates. But they also seek to coordinate behavior, hunting as a pack and engaging in group projects, which requires communication and so limits the scope of specialization and diversity. The tension between the drive to differentiate and coordinate, to compete and cooperate, prevents either pole from dominating.

If Neanderthals didn't specialize, they also didn't diversify. It may be that this lack of group diversity reduced their problem solving powers. Even if individual Neanderthals were highly capable their groups may not have been as good at problem solving or as quick to adapt and evolve.

See Independent Cacophony and Tag Teams for background posts that make this one comprehensible.