Reductionism--understanding complex processes by breaking them into simpler elements--dominates scientific thinking around the world and has certainly proved a powerful tool, leading to major discoveries in every field of science. But reductionism can be taken too far, especially in the life sciences, where sociobiological thinking has bordered on biological determinism. Thus popular science writers such as Richard Dawkins, author of the highly influential The Selfish Gene, can write that human beings are just "robot vehicles blindly programmed to preserve the selfish molecules known as genes." Indeed, for many in science, genes have become the fundamental unit for understanding human existence: genes determine every aspect of our lives, from personal success to existential despair: genes for health and illness, genes for criminality, violence, and sexual orientation. Others would say that this is reductionism with a vengeance. In Lifelines, biologist Steven Rose offers a powerful alternative to the ultradarwinist claims of Dawkins, E.O. Wilson, Daniel Dennett and others. Rose argues against an extreme reductionist approach that would make the gene the key to understanding human nature, in favor of a more complex and richer vision of life. He urges instead that we focus on the organism and in particular on the organism's lifeline: the trajectory it takes through time and space. Our personal lifeline, Rose points out, is unique--even identical twins, with identical genes at birth, will differ over time. These differences are obviously not embedded in our genes, but come about through our developmental trajectory in which genes, as part of the biochemical orchestra of trillions of cells in each human body, have an important part--but only a part--to play. To illustrate this idea, Rose examines recent research in modern biology, and especially two disciplines--genetics (which looks at the impact of genes on form) and developmental biology (which examines the interaction between the organism and the environment)--and he explores new ideas on biological complexity proposed by scientists such as Stuart Kauffman. He shows how our lifelines are constructed through the interplay of physical forces--such as the intrinsic chemistry of lipids and proteins, and the self-organizing and stabilizing properties of complex metabolic webs--and he reaches a startling conclusion: that organisms are active players in their own fate, not simply the playthings of the gods, nature, or the inevitable workings out of gene-driven natural selection. The organism is both the weaver and the pattern it weaves. Lifelines will be a rallying point for all who seek an alternative to the currently fashionable, deeply determinist accounts which dominate popular science writing and, in fact, crowd the pages of some of the major scientific journals. Based on solid, state-of-the-art research, it not only makes important contributions to our understanding of Darwin and natural selection, but will swing the pendulum back to a richer, more complex view of human nature and of life.