In this work of popular science, Arsuaga (paleontology, Universidad Complutense, Spain) sides with the view that Cro-Magnons (the ancestors of modern humans) and Neanderthals waged a struggle for survival that resulted in the complete extinction of the physically heartier species. He sketches a picture of the world inhabited by the two species and suggests that Neanderthals were much more similar to their Cro-magnon relatives and to modern humans, in terms of consciousness and culture, than has previously been thought. His view is strengthened by the Neanderthal-made necklace that he discovered while on a dig in the Sierra de Atapuerca in Spain. Annotation c. Book News, Inc. , Portland, OR (booknews. com)