Where in Guns, Germs, and Steel does Jared Diamond argue that early food production leads to the creation of complex societies?
Diamond advances this argument in Chapter Four, entitled "Farmer Power." He points out that societies that develop agriculture can produce more consistent and dependable food sources, which facilitates population development. This happens both for the obvious reason, that agricultural societies can feed more people and because agriculturalists are more likely to be sedentary, making it easier to raise children. Agriculture contributes to the development of civilization in other ways, too. Farming societies produce surpluses that can support non-agriculturalists. This often leads to the development of bureaucracy and centralized political power. As Diamond observes on page 89:
...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 full-time specialists, who instead first appear in sedentary societies.
Agriculture also makes technological development possible, and it leads to some of the unintended consequences that contributed to the dominance of European civilizations. Densely populated civilizations that lived in close proximity to livestock, for example, experienced the types of epidemic diseases that would wipe out Native American populations.
Source: Diamond, Guns, Germs, and Steel, 89.