Speedy, determined bacteria, and expert protist architects, caught between an tectonically active Earth and an energetic sun, engage in wars, alliances, bizarre sexual encounters, mergers, truces, and victories to create species. Random mutations and an omnipotent deity, say Margulis (geosciences, U. of Massachusetts-Amherst) and New York City science writer Sagan, played no part. Annotation c. Book News, Inc. , Portland, OR (booknews. com)