Scientists have identified a series of milestones in the evolution of the human food quest that they anticipate had far-reaching impacts on biological, behavioral and cultural evolution: the inclusion of substantial portions of meat, the broad-spectrum revolution and the transition to food production. The foraging shift to dense and predictable resources is another key milestone that had consequential impacts on the later part of human evolution. The theory of economic defendability predicts that this shift had an important consequence: elevated levels of intergroup territoriality and conflict. In this talk, I integrate this theory with a well-established general theory of hunter-gatherer adaptations and make predictions for the sequence of appearance of several evolved traits of modern humans. I review the distribution of dense and predictable resources in Africa and argue that they occur only in aquatic contexts (coasts, rivers and lakes). The paleoanthropological empirical record contains recurrent evidence for a shift to the exploitation of dense and predictable resources by 110,000 years ago, and the first known occurrence is in a marine coastal context in South Africa. Some theory predicts that this elevated conflict would have provided the conditions for selection for the hyperprosocial behaviors unique to modern humans.