Evolution. Douglas J. Futuyma. Sinauer, Sunderland, MA, 2005. 603 pp., illus. $89.95 (ISBN 0878931872 cloth).
As all evolutionists know, Douglas J. Futuyma, a professor at the State University of New York at Stony Brook, is the author of a successful textbook about evolution. The third edition of Evolutionary Biology (Sunderland, MA: Sinauer) appeared in 1998, weighing in at nearly 1000 large-format pages, including references and other subsidiary material. Evolution is Futuyma's update of the earlier text, with a welcome 40 percent reduction in length. It includes two chapters written by other authors, “Evolution of Genes and Genomes” (chapter 19), by Harvard's Scott V. Edwards, and “Evolution and Development”(chapter 20), by John R. True, Futuyma's colleague at Stony Brook. Evolutionary studies have advanced at a fast pace in the last seven years. The new book fittingly incorporates recent knowledge from molecular biology, genomics, population genetics, paleontology, ecology, and animal behavior, although these terms do not appear in any of the chapters' titles. There is no separate chapter on human evolution and variation, which was the subject of the final chapter in Evolutionary Biology; much of what was in that chapter appears dispersed throughout the new book.
“Evolutionary Science, Creationism, and Society” is the final chapter of Evolution, and at 20 pages is a useful expansion of the 5-page appendix, “Contending with Creationism,” in the previous textbook. More than 40 percent of Americans, including many college students and college-educated citizens, believe that Homo sapiens was directly created by God rather than having evolved, through several hominid species, from nonhuman ancestors shared with other primates and, ultimately, from very remote and very different sorts of organisms that are also ancestral to many other species on Earth. Some creationists believe that our planet is less than 10,000 years old, while others accept Earth's old age but claim that God's special action is required to account for the different kinds of organisms. A recently revived version of this view is known as intelligent design (ID).
The argument from design was articulated by the English theologian William Paley in his book Natural Theology in 1802, with greater cogency and more extensive knowledge of biological detail than has been shown by any other creationist author before or since, although modern authors adduce biochemical or mathematical considerations that were unknown in Paley's time. Paley's argument derives from a notion akin to what some contemporary authors have named “irreducible complexity,” which he calls “relation”: the presence of several parts interacting with each other to produce an effect that cannot be accomplished if any of the parts is missing. This argument is fallacious and has been refuted with evolutionary evidence. As Futuyma writes in Evolution, “an adaptation that we see today may indeed require precise coordination of many components in order to perform its current function, but the earlier states, performing different or less demanding functions, and performing them less efficiently, are likely to have been an improvement on the ancestral feature” (p. 534).
A telling example is the presence among living species of molluscs of a gradation from very simple “eyes” consisting of just a few contiguous pigmented, light-sensitive cells, as in the limpet Patella, to the eye of the octopus, as complex and effective an organ of vision as the human eye. Between these extremes are several intermediate conditions, such as the “pinholelens” eye of Nautilus, with a full array of light-sensitive cells forming an optic cup around a small opening for the entrance of light, and the eye of the marine snail Murex, with a single, primitive refractive lens and an optic nerve, although lacking the iris and cornea present in the octopus (see “Evolution, the theory of,” Encyclopaedia Britannica, 15th ed.).
Intelligent design does not belong in science because it postulates an extranatural or supernatural agent and because it cannot be scientifically tested. This is because, as proponents of ID state when confronted with contradictory evidence, we cannot know what the intentions of a supernatural designer are, or whether they may have allowed for a less than perfect design. Moreover, beyond scientific considerations, ID is theologically problematic: it is not simply that organisms are less than perfect, but also that the dysfunctions, oddities, waste, and cruelty pervasive in the living world are difficult to reconcile with the special action of an intelligent designer who is also benevolent. Many theologians, therefore, have rejected ID, preferring to see dysfunction, waste, and cruelty as results of a natural process—evolution—rather than as direct consequences of special action by an omnipotent and benevolent creator.
Futuyma effectively disposes of various red herrings adduced by creationists, such as the argument that evolution is only a theory. “A theory, as the word is used in science, doesn't mean an unsupported speculation or hypothesis…. A theory is instead a big idea that encompasses other ideas and hypotheses and weaves them into a coherent fabric”(Evolution, p. 527; see also p. 13). The modern theory of evolution embodies a complex array of knowedge from biology and other sciences, centered around Darwin's theory of evolution by natural selection and couched in genetic terms. It is not a single, simple theory with its corroborating evidence, but a multidisciplinary body of knowledge bearing on biological evolution, an amalgam of well-established theories and working hypotheses together with the observations and experiments that support accepted hypotheses (and falsify rejected ones), which jointly seek to explain the evolutionary process and its outcomes. Indeed, Evolution is an excellent compendium of the modern theory of evolution, although surely not a complete one, as no single book could possibly be.
Evolution's first chapter is a brief history of evolutionary ideas, from Lamarck through Darwin to the mid-20th-century authors of the “modern synthesis,” Theodosius Dobzhansky, Ernst Mayr, George Gaylord Simpson, and others. It also makes passing reference to Motoo Kimura's neutral theory of molecular evolution, and mentions molecular biology, developmental biology, and genomics as subdisciplines that recently have greatly contributed to evolutionary theory.
Treatment of the subject matter starts in earnest with several chapters (chapters 2–7) dedicated to the reconstruction of evolutionary history, including macro-evolutionary patterns and biogeographical diversity. Futuyma's treatment of the various methods available for inferring phylogenetic relationships is exemplary: clear, focused, and informative, with telling examples and illustrations. The discussion of molecular clocks, however, is much too brief and incomplete. There is only casual reference to the works and accomplishments of the last quarter-century. The relative-rate test is introduced without pointing out that it is of little value when the reference species is far removed from the subject species; nor is there any discussion of other pitfalls of the molecular clock, nor of why molecular clocks often yield older ages than paleontological data. The discussion of gene trees and gene genealogies is brief, but a few pages later, Futuyma clearly explains why an accurate gene tree may yield an inaccurate species phylogeny (because of preexisting and differential extinction of polymorphic alleles).
The chapters covering population genetics (chapters 8–12), phenotypic evolution (chapter 13), and sexual and social behavior (chapter 14) helpfully minimize the use of equations and mathematical symbols, while being profound and well balanced, and displaying the characteristic clarity of Futuyma's style. The discussion of molecular population variation, however, is surprisingly scant, all but ignoring the enormous amount of evidence gathered since the initial papers published in 1966 and 1983, respectively, on protein and DNA polymorphisms.
Chapters on species concepts and speciation, on life history evolution, and on species coevolution are delightful. Futuyma is thoroughly at home when describing reproductive isolating barriers and their genetic basis, the ascendancy of the biological species concept, interspecies competition, predator–prey coevolution, and related topics. The discussion of mimicry rings as an instance of multispecies interactions is suitably brief, but masterfully done.
The two guest chapters by Scott V. Edwards and John R. True are magnificent, remarkably comprehensive, clearly written, and beautifully illustrated. (I found the acknowledgment of these two authors' work surprisingly meager: their contributions are noted on the book's title page and credited in the preface, but their names do not appear in the table of contents or in the text of the chapters.)
Edwards begins “Evolution of Genes and Genomes” (chapter 19) with a fast-paced introduction to genome sequencing, microarray tests of gene expression, protein interaction networks (exemplified with a display of 20,405 interactions among 7048 Drosophila proteins), and adaptive molecular evolution in primates. Other topics in this chapter include the evolution of genome size, the processes by which new genes and gene families come about, and the adaptive diversification of gene families.
In his chapter (“Evolution and Development,” chapter 20), True engagingly summarizes the remarkable advances of evo-devo, with the Drosophila Hox genes serving both as a model of development and as a means of reconstructing the metazoan evolution of the Hox gene complex, from jellyfish and flatworm to mollusc and mammal. Gene regulation is introduced as the keystone of developmental evolution. The topics of homology, allometry, developmental constraints, and morphological evolution are presented with clarity and precision, and illustrated with beautiful photographs and still more beautiful (and more informative) graphics.
Evolution is a shorter book than the third edition of Evolutionary Biology, a change that represents (in my opinion) an improvement, but this is not the only or the most important improvement of the new over the old book. Evolution will serve well for undergraduate or graduate courses on evolution, and it has also served me well, and will serve other scientists, for reviewing the subject.