Bipedal protohumans, or Homo erectus, emerged in the African savanna four million years ago. Their adaptability and inventiveness was impressive. They made tools and learned to use and control fire. In addition to shaping biological evolution, these distinct behavioral traits enabled the early humans to migrate beyond the African savanna and into areas of Asia and Europe. From Homo erectus evolved Homo sapiens, which had larger braincases and changes in skeletal design and social behavior, and other changes. Homo sapiens expanded across the globe in an unprecedented manner. Humans’ extraordinary expansion and adaptability resulted from improvements in communication and cooperation.

Control of fire, song and dance, and speech are distinctive hallmarks of humans that transformed their relationship to the land and to each other. Fire, alongside the development and proliferation of tools for big game hunting, intensified humans’ ecological impact, while song and dance created a sense of cohesion and emotional solidarity among communities. Speech enabled a community of agreed-upon meanings, and the need to create continuity between those meanings and external realities drove innovation and invention. Together, these hallmarks enhanced specialization, as evident in the gendered division of labor in hunter-gather communities and the role of spiritual experts as intermediaries between ordinary human beings and the spirit world.