1Becoming Human

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A close-up of a cave painting from Laas Geel. Cattle are depicted with long horns.

In the summer of 2017, the story of human origins was rocked by findings that pushed back, and relocated to a different region of Africa, the earliest evidence for Homo sapiens. The new arguments about the time and place of our origins were grounded in the work of a team of paleoanthropologists who traveled to Jebel Irhoud in Morocco to establish a more precise date for hominin remains that had been unearthed by miners in the 1960s. What the team found were stone tools and fossilized skull fragments (including a jaw) belonging to five individuals. Thermoluminescence dating of objects found with the bones, as well as uranium series dating of a tooth, showed that the Homo sapiens at Jebel Irhoud lived as early as 315,000 years ago—more than 100,000 years earlier than the previously accepted date of 200,000 years ago that had been determined from finds in East Africa.

Research on ancient DNA (aDNA) is also rewriting long-standing theories of human evolution and hominin migration throughout, and out of, Africa. Scientists have extracted aDNA from skeletons across Africa from people who lived in the region of Cameroon 3,000–8,000 years ago; in Ethiopia 4,500 years ago; and in Malawi and Tanzania 16,000–18,000 years ago. Such evidence not only reveals a great deal about the individuals whose aDNA is sequenced but also provides information on as long as 80,000 years of their genetic past. The picture of Homo sapiens migration and interaction on the African continent is changing as a result of this aDNA analysis. The current interpretation of the aDNA is that four lineages of Homo sapiens genetically split from one another between 200,000 and 250,000 years ago, independently pursuing hunting and gathering in southern, central, and East Africa and along the Sahel (the southern edge of the Sahara). The modern scientific creation narrative evolves as new evidence unearthed through excavation and new ways of studying that evidence add more data to the story that scholars work to piece together.

Even though Homo sapiens existed 300,000 years ago, what we think of as being human is a much more recent development. Most of the common traits of human beings—the abilities to make tools, engage in family life, use language, and refine cognitive abilities—evolved over many millennia and crystallized around the time Homo sapiens migrated out of Africa more than 100,000 years ago. Only with the beginning of settled agriculture did significant cultural differences develop between groups of humans, as artifacts such as tools, cooking devices, and storage containers reveal. Put simply, the differences we think of as separating humankind’s cultures today are less than 15,000 or 20,000 years old.

This chapter lays out the origins of humanity from its common source. It shows that many different hominins preceded modern humans and that humans came from relatively recent migrations out of Africa and across Eurasia in waves. Flowing across the world, our ancestors adapted to environmental constraints and opportunities. They created languages, families, and clan systems, often innovating to defend themselves against predators. One of the biggest breakthroughs was the domestication of plants and animals and the creation of settled agriculture. With this development, humans could stop following food and begin producing it where they desired.