Chapter 11 begins with a breakdown of how our genus is defined. There is an enlargement of our brains, a flattening of the face along with a reduction in tooth and jaw size, refined bipedalism, longer legs and shorter arms, increasing reliance on culture and ability to manipulate our environment and finally our ability to migrate all over the world. The first members of our genus to exhibit some of these features is Homo habilis who is attributed with the creation of the Oldowan tool tradition. This technique is described along with details about Homo habilis fossils.

The next species to be discussed is that of Homo erectus who is all over the Old World and characterized by large brow ridges or torus, a more pronounced post orbital constriction than later species and a sagittal keel. Theories surrounding why Homo erectus migrated are given. The tool technology most closely associated with Homo erectus is the Acheulean technique that produces hand axes and bifacial flaked points. There is some evidence reconstructed from the base of the skull that suggests they had some capacity for language.

Homo antecessor and Homo heidelbergensis are described next. There is some debate as to whether Homo antecessor is a new species or not. Both of these species are found in Spain but Homo heidelbergensis can be found throughout much of the Old World. Homo heidelbergensis physically appears to be an intermediate between Homo erectus and modern Homo sapiens. The Levallois technique is explained.

The next section focuses on the Neandertals. The interpretation of Neandertals by anthropologists were originally based off a single skeleton that made them appear brutish and hunched over. Current interpretations show them to be much closer in appearance to modern humans than previously thought. They appear to be cold adapted with shorter limbs and a stockier build while being incredibly robust and strong. Their noses are broad and some fossilized remains appear to have specialized bony projections within the nasal cavity that may have provided a greater surface area to warm and moisten the air. They used a specialized tool technology called Mousterian that included retouching of many of their tools overtime. There is some controversial evidence that they purposefully buried their dead and took care of the sick, injured and elderly.

Fully modern humans appear by around 160,000 ya, with the earliest finds being from Ethiopia. They exhibit a broader range of cultural artifacts including stone figures, art and bone tools.

The last section of the chapter covers the debate over the origin of modern humans both where and when they appeared. The Multiregional Evolution Model and the African Replacement Model are proposed. Evidence is provided from the fossil record, the archaeological record and genetics.

After reading the chapter you should be able to answer the following questions:

How can we best go about describing and organizing the fossil evidence for the evolution of genus Homo?

What do we know about the dates, the distribution, and the physical appearance of the various groups of fossils assigned to genus Homo?

What can we say about their lives, particularly about their cultural behaviors?

What is the debate over modern human origins and can it be resolved?