People commonly view evolution as a process of competition between individuals--known as "survival of the fittest"--with the individual representing the "unit of selection." Richard Dawkins offers a controversial reinterpretation of that idea in The Extended Phenotype, now being reissued to coincide with the publication of the second edition of his highly-acclaimed The Selfish Gene. He proposes that we look at evolution as a battle between genes instead of between whole organisms. We can then view changes in phenotypes--the end products of genes, like eye color or leaf shape, which are usually considered to increase the fitness of an individual--as serving the evolutionary interests of genes. Dawkins makes a convincing case that considering one's body, personality, and environment as a field of combat in a kind of "arms race" between genes fighting to express themselves on a strand of DNA can clarify and extend the idea of survival of the fittest. This influential and controversial book illuminates the complex world of genetics in an engaging, lively manner.