Describe how early Pleistocene climate change influenced the evolution of the genus Homo.
Identify the characteristics that define the genus Homo.
Describe the skeletal anatomy of Homo habilis and Homo erectus based on the fossil evidence.
Assess opposing points of view about how early Homo should be classified.
The boy was no older than nine years when he perished by the swampy shores of the lake. After death, his slender, long-limbed body sank into the mud of the lake shallows. His bones fossilized and lay undisturbed for 1.5 million years. In the 1980s, fossil hunter Kamoya Kimeu, working on the western shore of Lake Turkana, Kenya, glimpsed a dark-colored piece of bone eroding in a hillside. This small skull fragment led to the discovery of what is arguably the world’s most complete early hominin fossil—a youth identified as a member of the species Homo erectus. Now known as Nariokotome Boy, after the nearby lake village, the skeleton has provided a wealth of information about the early evolution of our own genus, Homo (see Figure 10.1). Today, a stone monument with an inscription in three languages—English, Swahili, and the local Turkana language—marks the site of this momentous fossil discovery.
Chapter 9 described our oldest human ancestors, primarily members of the genus Australopithecus, who lived between 2 million and 4 million years ago. This chapter introduces the earliest members of the genus Homo, focusing on Homo habilis and Homo erectus.