ANCESTORS: In Search of Human Origins, by Donald Johanson, et al., Villard Books, 339 pages, $27.50.

“Ancestors” is the companion volume to Donald Johanson’s recent Nova TV series of the same name and covers the same ground but in greater detail.

Johanson made his scientific reputation in 1974 with the discovery of “Lucy,” a 3-million-year-old fossil skeleton that represented the earliest known example of bipedalism. He gained notoriety by challenging the Leakeys, the most prestigious names in anthropological circles, as to how our earliest ancestors made their livings and why they came down out of the trees to walk upright.

The book starts with a description of a dig in the Hadar valley of Ethiopia and plunges into detailed discussions of brow ridges, jaw types, pelvic measurements, and whether markings on bones were made by wild animals or stone tools. Throughout, Johanson manages to keep the discussion interesting and presents a convincing argument that, far from being the fierce hunters that the Leakeys portrayed them, these early forerunners of the human race were wily, and rather timid, scavengers.

Another cherished belief that Johanson debunks concerns the Neanderthals, who are described in most books as brutish creatures of low intelligence with no chance of competing against the smaller but much more intelligent Cro-Magnons, the last stage before modern humans. The common belief that the Neanderthals disappeared whenever the Cro-Magnons appeared on the scene is not true, says Johanson, who has found evidence of their living in the same areas together for extended periods. It is more likely, he says, that the Cro-Magnons survived and the Neanderthlals died out because of a difference in their diets. The Neanderthals depended on a vegetable food source alone while the Cro-Magnon diet included a wide variety of meat. This made the difference between survival and extinction for the two species.

Johanson ends his book with beautiful illustrations of cave art and makes the moving case that “art was at the center of the revolution from which fully modern humans emerged.” The book, considering the fact that its subject is bones, is engaging and informative. An extensive bibliography makes it a useful reference that should make it of interest to public and school librarians.

This is an excellent nontechnical and readable book for anyone interested in the long, and frequently controversial, path from the first primitive hominids to modern humans.

Clair Wood is a science instructor at Eastern Maine Technical College and the NEWS science columnist.