ANCESTORS is yet another popular science title which covers the question of human origins, detailing the discoveries made by archaeologists during the past 150 years and the information that has been gleaned from their fossil finds.

Author Donald Johanson is preeminent among contemporary field archaeologists, noted worldwide for his discovery in 1974 of the Lucy fossil, which he eventually classified as Australopithecus afarensis. This famous skeleton, a female about three feet tall, is dated at 3.2 million years old and is complete enough to show clearly that this pre-human walked upright but retained many apelike features, including a small brain—a true “missing link.” Johanson tells again the story of his discovery of Lucy, showing in interesting detail what archaeologists do.

In subsequent chapters, Johanson travels four continents and three million years in his quest to show how humans developed from these early hominids. He talks about each of the major ancestral species, the archaeological evidence supporting their identification as a species, and the current thinking on what they were. He discusses Australopithecus afarensis and the other australopithecenes, who walked upright but were apelike; Homo habilis, the “handy man” who used crude stone tools; Homo erectus, the widespread human ancestor who was the first to use controlled fire and possibly the first to hunt; archaic Homo sapiens, appearing perhaps 200,000 years ago and transitional between Homo erectus and modern humans; Homo neanderthalensis, an intelligent species that buried their dead but are not thought to be an ancestor of modern humans; and Homo sapiens, which appeared some 100,000 years ago.

Along the way Johanson analyzes several hotly debated issues, including discussions of why hominids developed an upright posture, whether human ancestors were primarily hunters or scavengers, and when Homo sapiens evolved.