Book Review

The Outer Reaches of Life

N Engl J Med 1994; 330:1026-1027April 7, 1994

Article

The Outer Reaches of Life
By John Postgate. 267 pp. New York, Cambridge University Press, 1993. $24.95. ISBN: 0-521-44010-6

Postgate's accounts of the weird and wonderful ways of microbes are stories both of sophisticated science and of the extremes in the biologic world. In contrast to plants and animals, single-cell organisms exhibit a wide range of biologic activities and occupy diverse ecologic niches, from deep-sea hydrothermal vents at 112 °C to salt pans at 5-M sodium chloride to the intestines of 11,000-year-old mastodon remains. This book has two aims: to describe “all the processes of which living cells are capable” and, along the way, to provide the nonscientist reader with “the cultural delight in understanding science.”

The approach taken for each group of microbes is to go first into a bit of the current scientific thinking needed to understand their characteristics -- for example, the remarkable tolerance to heat shown by the thermophiles. In this case, Postgate considers the problem of enzyme action and protein stability in terms of the familiar activity of cooking an egg and the coagulation of the albuminous egg white. Technical terms and jargon are kept to a minimum, and the writing has an informal grace and charm.

An important contribution of the study of the “outer reaches of life” has been to inform speculation about the origin of life under prebiotic conditions. Postgate devotes considerable attention to these fascinating ideas, ranging from the rather conventional, such as Oparin's primitive soup, to the outer reaches of a proposal for the biologic reclamation of Mars for human habitation by the introduction of appropriate microbes.

Peer review has its problems when it comes to evaluating a book on science aimed at an audience of nonscientist readers. Having a passing acquaintance with the field, I find some of the author's scientific discussions, such as that on the structure of RNA, too arcane to sustain the interest of a nonscientist reader. Other topics are treated too hastily -- for example, the natural history and interesting ecologic characteristics of some of the little-known microbes Postgate describes. Likewise, in most of the chapters, the scientific background is presented first, followed by the biologic illustrations and examples. This arrangement is fine for scientists who can see where the discussion is headed, but for readers unfamiliar with the field, it might have been better first to pique their interest with the biologic examples and then to give the scientific explanations.

For readers with the usual training in medical microbiology, which focuses on mammalian pathogens, this book provides an enjoyable introduction to the broader field of microbiology. It also reviews current thinking about a wide variety of basic biologic and biochemical problems, from evolution to nitrogen fixation to the design of industrial enzymes.

William C. Summers, M.D., Ph.D.
Yale University School of Medicine, New Haven, CT 06510