At first this seems to be one of those tediously scrupulous YA introductions which must fill in every area of possibly relevant background before proceeding with the subject at hand. Thus words like photosynthesis, food chain, homeostasis, electroencephalography, chromosome and valency, are italicized and defined in progress, and we are exposed to a survey covering sequoias as a climax community, fossil findings of early man, the work or thoughts of Darwin, Mendel, Descartes and Pasteur, the rise and fall of civilizations up to the technological revolution, and Teilhard de Chardin's prospect of a collective world intelligence or noosphere -- before we come, about half way through the book, to the first mention of genetic engineering. But it turns out that that topic itself only takes up a chapter (concerned mainly with preventing birth defects) and we go on from there to transplants and implants, the energy crisis (detouring to the discovery of fire and the laws of thermodynamics), pollution and population problems, contraception methods (""menstruation begins in puberty. . ."") and schools of psychotherapy -- so that the whole book becomes a sort of background briefing, interspersed with pronouncements on man's treatment of spaceship earth, which Heintze acknowledges at the end in a passage on bioethics to be his real concern. True, this theme is sounded early on with a call for man to come into balance with nature, and Heintze reminds us intermittently that man must remake himself, respect natural laws, and humanize the earth; even the chapter on genetic engineering stresses the question of who will name the controllers. But these questions are never explored, much less related to the deluge of data that is likely to try the patience of the most dogged grind.