In this fresh and personalized take on genetics, Hubbell (Waiting for Aphrodite, etc.) argues that "we have been 'genetic engineers' in the past, and we will continue to do so in the future." There is currently a spate of books weighing in on both sides of the controversial genetic engineering debate, and this one stands out for its memoir feel as well as its straightforward thesis, which aims to put the debate firmly in the context of past genetic tinkerings. Hubbell shows how farmers 7,500 years ago engineered what came to be known as corn from a botanical anomaly of a kind of "naturally occurring" grass (though when finished with this book, readers may find themselves second-guessing what constitutes "natural"). The result was a dependable and essential man-made foodstuff, which, because of its genetic enhancement, cannot reproduce itself each planting season today without human help. A similar case of mutual dependence resulting from our ancestors' genetic tinkering, Hubbell shows, is the silkworm, a species "minted by human ingenuity" to spin its costly trade commodity, but at the expense of its protective coloring and ability to fly. Today, the silkworm depends on its human keepers for its food and shelter, as does Hubbell's next case study, the house cat. Like the silkworm, the modern-day cat lost its edge in the wild through domestication, in the cat's case through diminished size, sight and reflex ability. Finally, Hubbell shows how apple growing in America was perhaps "the greatest genetic experiment ever performed by human beings," yielding as many as 7,000 genetic varieties by the 1800s, a number that has since been narrowed by market demand to about a dozen. Throughout, Hubbell delves into the history behind her case studies, interspersing her narrative with her accounts of living in Washington and Maine. (Oct. 15)