.A separate consequence of a settled existence is that it permits one to store food surpluses, since storage would be pointless if one didn't remain nearby to guard the
stored food. While some nomadic hunter-gatherers may occasionally bag more food
than they can consume in a few days, such a bonanza is of little use to them because
they cannot protect it. But stored food is essential for feeding non-food-producing
specialists, and certainly for supporting whole towns of them. Hence nomadic
hunter-gatherer societies have few or no such full-time specialists, who instead first
appear in sedentary [settled] societies - Jared Diamond, Guns, Germs, and Steel
Which change in history is most closely associated with the passage above?