In 1974, while on a mapping expedition in Ethiopia (Figure 2.2), an American paleoanthropologist named Donald Johanson and a colleague stumbled upon a skeletal forearm and skull in a gully. Upon closer inspection, they not only found more bones but also realized that all of them had belonged to some type of early human. After careful work, Johanson’s team was able to recover about 40 percent of the skeleton, which they named Lucy after the popular Beatles song, “Lucy in the Sky with Diamonds.”
We now know that, though small, Lucy was an adult when she died about 3.2 million years ago. Scholars have learned a great deal since her discovery, about her but also about many of our other evolutionary ancestors. In the millions of years since Lucy walked the Earth, a number of early human species have come and gone. Some migrated out of Africa and populated portions of Asia, Europe, Australia, and the Americas. These different species developed new tools, learned to control fire, mastered language, and produced stunning works of art. Then, about twelve thousand years ago, some of our own species adopted agriculture. With this innovation, many early human groups began to end their hunting and gathering ways and establish settled communities.