In the book Sapiens, Yuval Noah Harari discusses archaeological evidence that Homo sapiens engaged in trade tens of thousands of years ago. He also suggests that evidence of trade can be used to explain how Homo sapiens could have out competed other human species.
For example, Harari suggests that Neanderthals probably couldn’t cooperate to the same extent as sapiens. He also suggests that a Neanderthal would win in a fight with a Sapiens, but that individual fights between human species was not the main form of competition. Large numbers of Sapiens could communicate and share goals through myths and stories, allowing them to gang up on stronger species like Neanderthals. Comparing the cognitive level of the two species, Harari explains how differences in trade support ideas of different levels of cognition, and the advantages that Sapiens had:
“Archaeologists excavating 30,000-year-old Sapiens sites in the European heartland occasionally find there seashells from the Mediterranean and Atlantic coasts. In all likelihood, these shells got to the continental interior through long-distance trade between different Sapiens bands. Neanderthal sites lack any evidence of such trade. Each group manufactured its own tools from local materials.”
Sapiens and Neanderthals were both tool users, but Sapiens appeared to be traders with foreign bands. While Neanderthals constructed all their tools themselves, Sapiens could get different tools from different bands, could get decorative seashells, and could coordinate and cooperate among themselves and others. This communication and cooperation is what Harari argues gave Sapiens an advantage over species like the Neanderthals, and what eventually allowed Sapiens to outcompete other species and ultimately become modern Homo sapiens.