Origin and Early Evolution of Life. Tom Fenchel. (2002, Oxford University Press.) 171 pages, 7 color plates

Origin and Early Evolution of Life. Tom Fenchel. (2002, Oxford University Press.) 171 pages, 7 color plates. It is the task of scientists interested in the origin of life to discover how life could have emerged in the chaotic prebiotic environment, under conditions that we would call extreme environments today. These investigators have gone far beyond the conventional view that biology is confined to the biosphere. Instead, life is considered to be part of a continuum of emergent processes that began with the Big Bang, followed by star formation and the synthesis of biogenic elements, then accretion of planets around certain stars, and finally the origin of life when one such planet becomes habitable. The basic requirements for life today are liquid water, a mix of organic compounds we call nutrients, and a source of energy to drive metabolic reactions. The earliest forms of life would have the same requirements, and that’s why we are so delighted by recent evidence that Mars once had seas. It is even possible that microbial life began first on Mars, then was delivered to the early Earth on meteorites. Could it be that all life on the Earth can be traced back to a Martian origin? Although the answer is only a firm ‘‘maybe,’’ we can no longer say ‘‘No way!’’ As a result of this enlarged perspective, there is a strong and continuing demand for readable books dealing with beginnings, as witnessed by the phenomenal success of a book with the most unlikely title, A Brief History of Time, by Stephen Hawking. Millions of thoughtful readers worldwide have an abiding interest in how things begin, be it the universe, the human race, or life itself. This burgeoning market has led to the recent publication of perhaps a dozen books on the origin and early evolution of life. These include Planets and Life, edited by Woodruff Sullivan and John Baross, Genesis: The Scientific Quest for Life’s Origins by Robert Hazen, Astrobiolog y: A Brief Introduction by Kevin Plaxco and Michael Gross, The Spark of Life/Darwin and the Primeval Soup, by Christopher Wills and Jeffrey Bada, Life on a Young Planet: The First Three Billion Years of Evolution on Earth by Andrew Knoll, and Life’s Origin: The Beginnings of Biological Evolution by J. William Schopf. Tom Fenchel’s book, entitled Origin and Early Evolution of Life, therefore has strong competition in the marketplace. Fenchel is a professor of marine biology at the University of Copenhagen, director of the Marine Biology Laboratory there, and author of two books on bacterial metabolism. His paperback book has 14 chapters, a glossary, and an index, and includes a selection of color plates illustrating microfossils, stromatolites, and cyanobacteria. The first three chapters present an introduction and a brief history of the field, and in Chapter 4 the author attempts to define life in a useful way. The origin of life is sketched out in Chapters 5 and 6, comprising six pages each, and the evolution of metabolism is covered in Chapter 7. A description of early evolution occupies the last half of the book. Fenchel’s text can be considered a brief (155 pages) overview of the field. His writing style has a textbook quality, with only a few concepts that are original with the author. One of these is presented in Chapter 11, entitled ‘‘Our Anaerobic Inheritance,’’ but the chapter is only three pages long. This is not a trade book, but is more of an extended review arising from the author’s lectures on evolution to undergraduate audiences, so that most of the material will also be found in other books. The one place where the author steps out of a straightforward descriptive style is a brief section with the subtitle ‘‘Gaia hypothesis as pseudoscience,’’ in which he argues that Gaia as developed by James Lovelock has no explanatory power, and therefore cannot be classified as science. As noted above, Fenchel’s book is competing with a number of others that cover the same territory. The books cited earlier were authored by well-established experts, and provide enjoyable