The rapid development of AI has exposed long-standing weaknesses in how the social sciences explain behavior, meaning, and social order. As machines increasingly replicate tasks once thought uniquely human, the question is no longer whether the social sciences must rethink themselves, but how. This book argues that the most robust and enduring contributions to the social sciences are those grounded in evolutionary theory. By drawing systematically on biology, cognition, culture, and systems thinking, it develops a coherent framework for organizing the social sciences around a shared understanding of human nature. Especially in light of AI, the future may demand us to define our humanity not only by intelligence, but also by responsibility and stewardship. In this sense, the renewal of social science unfolds within a broader ethical horizon relevant to planetary sustainability.