A recent CBS World News article quoted Bjoen Ulvaeus, former member of the group ABBA, saying, "I can't see why we should be printing bank notes at all anymore," advocating that the world's economy should run without cash.
Our ancestors did not need money. Early humans were self-sufficient, hunter-gatherers, who relied on their surroundings for shelter and clothing. There are still remote tribes that do not use money as a medium of exchange but barter with other tribes when they have excess food. We are still bartering services today in modern societies.