An ambitious and evenhanded meditation on the science of genetics, its potential, and its ethical implications. Arguing that we must know where we came from to understand where we are going, British science journalist Tudge (Future Food, 1980) summarizes the history of genetics, starting with a somewhat dry and dutiful primer on evolution and molecular biology. While he clearly connects the dots between Darwin, Mendel, and Watson and Crick, the material will be rough going for a lay reader. More satisfying are later sections on cloning, the Human Genome Project, and genetic engineering. Tudge provides a thorough overview of the field but is more interested in science than technology, giving less space to recombinant crops and livestock improvement than to issues of genetic diversity and species conservation. Indeed, he is at his best describing animals, and well-drawn examples--from the mating practices of the funnel-web spider to the selective nursing habits of red deer--provide the book's liveliest moments. Also intriguing are meditations on polygamy versus monogamy in the natural world, the inefficiency of sexual reproduction, why we will never evolve into superhumans, and why the notion of a Jurassic Park is remotely plausible but ultimately flawed. These accessible musings locate genetics issues in a more familiar context, to which the author adds his own humanistic and theological perspectives. Tudge believes science and scientific literacy can make a better world. But, as the book forcefully demonstrates, there are aspects of evolution, both human and technological, that cannot be controlled; hence, Tudge argues for restraints on a technology that he feels society is not ready for. A challenging work that's worth reading, but requires patience.