Over the last three million years or so, our lineage has diverged sharply from those of our great ape relatives. Change has been rapid (in evolutionary terms) and pervasive. Morphology, life history, social life, sexual behavior, and foraging patterns have all shifted sharply away from other great apes. No other great ape lineage--including those of chimpanzees and gorillas--seems to have undergone such a profound transformation. In The Evolved Apprentice, Kim Sterelny argues that the divergence stems from the fact that humans gradually came to enrich the learning environment of the next generation. Humans came to cooperate in sharing information, and to cooperate ecologically and reproductively as well, and these changes initiated positive feedback loops that drove us further from other great apes.
Sterelny develops a new theory of the evolution of human cognition and human social life that emphasizes the gradual evolution of information sharing practices across generations and how information sharing transformed human minds and social lives. Sterelny proposes that humans developed a new form of ecological interaction with their environment, cooperative foraging, which led to positive feedback linking ecological cooperation, cultural learning, and environmental change. The ability to cope with the immense variety of human ancestral environments and social forms, he argues, depended not just on adapted minds but also on adapted developmental environments.