Overcoming Bias and great discussion

What came first, trade or farms; and do anthropologists have a bias?
Before I get into their writings on the topic, I admit my bias. I think all anthropology would be served by looking at the Dryus event as the demarcation point for cities or farms or trade. We know that cities existed before the freeze and the start of the Holocene, the stable 12,000 years.

From there I ask what proto farming might look like. Simple people throwing seed out to get a harvest for a year before moving on. That kind of activity would create oasis of growing food near water ways, easy to do even for a migrating species. So agriculture would have exploded during the thousands of years of expanding spring, after Dryus. Yet we know from under water archeology that cities pre-existed Dryus.