American Scientist

EVOLUTION: The First Four Billion Years. Edited by Michael Ruse and Joseph Travis. xii + 979 pp. The Belknap Press of Harvard University Press, 2009. $39.95.

Much of the American public displays a curiously paradoxical view of evolution, considering it good in fashion, movies, restaurants and culture (thank God disco and the rest of the 1970s are gone!), and, to a degree, in music and cars, but bad in politicians and biology. As far as I know, no state legislature has yet decided to ban the evolution of the flu virus, but such an event seems not far off. The problem, of course, is not with evolution used as a synonym for change, as it is by much of the public and by many scientists. Rather, the problem arises with Charles Darwin’s concept of descent with modification and his critical identification of natural selection as the predominant mechanism behind evolutionary change in biology. Those are the most important ideas presented in Darwin’s On the Origin of Species, published 150 years ago this fall. The sesquicentennial of the Origin coincides with the bicentennial of Darwin’s birth and has generated the expected outpourings of books, conferences and celebrations.

Evolution: The First Four Billion Years, edited by Michael Ruse and Joseph Travis, is one of the more curious contributions to this literature: Part encyclopedia, part collection of essays, it presents an interesting jambalaya to the reader. The first third or so of the book consists of 16 essays on an eclectic mix of topics, ranging from the origins and history of life to facets of the evolutionary process and onward to the relation of evolution to society and to religion. The encyclopedia that makes up the remainder of the volume includes about two hundred short essays on important evolutionary concepts (the endosymbiotic origin of eukaryotes; homology), significant figures in evolutionary thought (Hampton Carson, J. B. S. Haldane and Bishop Wilberforce all make appearances), and a collection of important books in evolution (from E. B. Ford’s Ecological Genetics to Philip Sheppard’s Natural Selection and Heredity).

In his foreword to the book, Edward O. Wilson addresses the extent to which evolution has laws, at least in the sense that the term is commonly used in other sciences. This was an issue that greatly concerned Darwin as he wrote the various editions of the Origin and his later books. Newton’s work in physics had established the importance of laws as a foundation for science. As a geologist, Darwin was trained in the perspectives of James Hutton and Charles Lyell, who championed the regularities of geological processes against the views of catastrophists, who rejected any lawlike regularities. Darwin and his colleagues believed that an evolutionary view of life would not gain acceptance unless it linked natural selection and descent-with-modification with an emphasis on law and regularity. For this reason Darwin rejected the possibility that the nature of the evolutionary process may have changed over time. The form that these regularities take in biology is very different from what is seen in physics, however. In biology one finds regularities of process that permit few predictions about macroscopic outcomes. Ultimately Darwin’s views triumphed—his strategy was successful.

But from this success also came a lineage of biologists, beginning with D’Arcy Wentworth Thompson, who argued for an alternative foundation for the lawlike regularities of evolution. The adherents to this view suggest that physical processes such as surface tension and scaling factors have played a primary role in evolution—a role more important, perhaps, than that of natural selection. The ubiquity of scaling relationships between body mass and various aspects of the function of organisms suggests general principles of biologic design. In an essay titled “Beyond the Darwinian Paradigm: Understanding Biological Forms,” Brian Goodwin provides an introduction to this alternative perspective on evolution, and although I do not think that this line of argument is generally correct, it does provide a valuable counter to received wisdom.

The more general issue of “laws of evolution” versus the contingency of history reappears, at least implicitly, in other contributions to this volume. It probably deserves more attention than it has received from most evolutionary biologists.

There are some gems among the contributions to the encyclopedic portion of the book, but almost as many seem designed to fuel late-night graduate student discussions of what the rationale for their inclusion could possibly have been. Informed readers will be in a quandary as to why some of their living colleagues are profiled in this section whereas others, seemingly equally meritorious, have been excluded. Many of the selections on historical figures will serve students as valuable introductions to figures who might unjustifiably fade from memory. Few would quibble with the inclusion of brief biographies of Ernst Haeckel or Ernst Mayr, or the synopsis of Robert Grant’s work. Stanley Miller’s contributions are likewise valuable. But other decisions seem rather arbitrary (where, for example is Rupert Riedl, or John Phillips, who produced the first diversity curves of the history of life and named the Paleozoic, Mesozoic and Cenozoic eras?).

Descent with modification was, as mentioned, a pillar of Darwin’s argument in the Origin and continues to play a critical role in our understanding of the evolutionary process. Fortunately, the development first of parsimony and more recently of Bayesian and likelihood approaches to phylogenetic analysis have revolutionized our understanding of everything from the tree of life and angiosperm phylogeny to metazoan relationships and the fine details of gene trees within broadly distributed populations of a species. Sadly, little of the power of these approaches has seeped into this compendium, beyond a short essay on phylogenetics and vignettes of Willi Hennig and Joseph Felsenstein.

For students and the general public, many of the essays in this volume provide useful introductions to a number of central issues in evolution, and the shorter contributions are a ready reference on a wide range of topics. But few of the essays are sufficiently novel to recommend them to specialists in evolutionary biology. Overall, Mark Pagel’s Encyclopedia of Evolution, published in 2002, remains a more generally useful resource.

Douglas H. Erwin is a Senior Scientist in the Department of Paleobiology at the National Museum of Natural History in Washington, D.C., and a professor at the Santa Fe Institute in New Mexico. He is currently completing a book with Jim Valentine titled The Cambrian Explosion: The Construction of Animal Diversity.