This volume addresses the origin of the human genus Homo, a major transition in human evolution and associated with major changes in brain size, locomotion, and culture, but one with many unanswered questions. How many different species of Homo were there, and how were they interrelated? Are stone tools a characteristic of early Homo? What was their function? How does the use of stone tools relate to changes in the dentition and brain size? Did adaptations for long distance running first appear with the origin of this genus? How does this relate to its diet and cultural abilities.