Cooperation lies at the heart of human evolution, shaping both our biology and our social environment. Here, we will examine the ecological and evolutionary foundations of cooperation through insights from long-term fieldwork among Hadza hunter-gatherers of northern Tanzania. Food sharing, community birth, distributed childcare, and sentinel sleep will be highlighted as interdependent strategies that act to structure human life history, buffer risk, and enhance survival. Situating Hadza practices within comparative and evolutionary frameworks, I argue that these systems reveal cooperation as a core adaptation that underpinned the emergence of our species. Understanding the ecology of cooperation among contemporary foragers provides critical perspective on the evolutionary pathways that made us an exceptionally collaborative species.