Andrew H. Knoll is a paleontologist who is particularly conversant with the integrative approaches of modern day evolutionary science. Rooted in the rocks, he writes with skill about the geological and geophysical processes at work in early earth formation, and their implications for the evolution of life. He explains the complex geochemistry that became, in time, a biochemistry. He describes the so-called evo-devo (I.e., evolutionary developmental biology) revolution with verve-both as an observer, and a participant/contributor. He describes in some detail how the evolution of life is largely one of microbiologic changes through geologic time. Some critics fault him for leaving the good stuff for the end-a bizarre criticism given that the "good stuff" (I.e., complex multi-cellular animal life) has only been around since very recent times in geological terms. Knoll deftly defeats this prejudice by pointing out that while animals are the kings of morphological variety, it is the microorganisms that are the exemplars of metabolism. Microbes have evolved diverse mechanisms for surviving on a catastrophically evolving planet. It is in fact, the microbes that made the planet habitable for animals. This is a story as epic and heroic as any produced by evolutions most complex, and ridiculously recent, product. If I had a quibble with the book, it was with the decision to include the final chapter about the possible Martian origin of terrestrial life. Not to say this story wasn't interesting, but it would have been better left to another book. Finally, Knoll's conclusion attempts to reconcile the seemingly ever-opposed science and religion and is reminiscent of Stephen J. Gould's "twin magisteria" argument. The stronger part of his conclusion reminded us that past may be prologue: That current action or inaction may have consequences in what could be, but doesn't have to be, our own evolutionary endgame.