Ernst Haeckel coined the term ecology in 1866, and the historical development of ecology as a recognizable discipline did not begin in earnest until the very end of the nineteenth century. Despite these relatively recent occurrences, the roots of ecology extend much further into the past, as Frank Egerton's survey ably demonstrates. Roots of Ecology: Antiquity to Haeckel is based on extensive scholarship that is carefully documented in hundreds of endnotes. Egerton has amassed a tremendous amount of useful historical information about how older specialties of botany, zoology, natural history, and physiology contributed to what we now recognize as ecology. His encyclopedic treatment of the ecological ideas of Aristotle and other ancient Greek and Roman naturalists to those of nineteenth-century protoecologists fills an important need in historical scholarship. Although much of this information is not new to professional historians of science, compiling it in an attractively illustrated volume serves a useful purpose for other scholars. Biologists interested in ecology's deep history will consider Roots of Ecology a helpful reference for tracing the precursors of present-day ecological questions and ideas.
Egerton, who is professor emeritus of history at the University of Wisconsin—Parkside, is considered the dean of historians of ecology. Beginning in the early 1960s, long before other historians had taken notice of ecology, Egerton explored the origins of population studies and important ecological ideas, such as the balance of nature. Those of us who began writing detailed histories of modern ecology in the late 1970s owe a debt of gratitude to Egerton's pioneering efforts. In addition to his contributions to the professional history of science, Egerton has become the unofficial historian for the Ecological Society of America. Over the years, he has contributed numerous historical articles to the society's journals—most notably, a series of more than 40 historical essays that have appeared in recent volumes of the Bulletin of the Ecological Society of America. These short articles provided the raw material for Roofs of Ecology, although the book is more than a collection of papers.
I admire Egerton's ambitious attempt to write a synthetic historical account of ecological ideas covering more than two millennia. Modern ecology is quite a diverse collection of specialties and its development from earlier natural history traditions was not a simple linear process. Furthermore, Egerton includes important contributions from physiology, medicine, and other fields that also affected this historical development. Unifying this mass of information is a daunting challenge, because no single, central theme is likely to encompass every facet of the history of ecology.
Egerton organizes Roofs of Ecology chronologically, although some later chapters also have thematic overlays. Chronology may seem logical, given the broad historical sweep of the book, but I found this organizational plan to be problematic. The lack of interpretive themes makes the chapters overly episodic and the narrative somewhat disjointed. Inevitably, related topics in important fields, such as botany and zoology, appear in several different chapters. Egerton frequently reminds the reader of this fact—a tactic that I sometimes found annoying. I was often tempted to use the index to skip from chapter to chapter, finding information on topics of interest, rather than reading chapters from start to finish.
Even within a single chapter, the overall treatment is, at times, confusing. For example, in the important chapter on nineteenth-century precursors to ecology, Egerton sandwiches an admirably detailed discussion of the rise of microbiology between sections on entomology and Ernst Haeckel's concept of ecology. Surely, the germ theory of disease has some ecological relevance, but the chapter provides no suggestion of how Koch, Pasteur, and other bacteriologists influenced either Haeckel or the later development of ecology. The abrupt transition between these topics is jarring. Intrepid readers may wade through Roofs of Ecology from cover to cover, but others may find that the parts of the book are more satisfying than the whole.
The task that Egerton set for himself in writing this book was gargantuan, and writing a tightly organized, compelling account within such a short space may have been impossible. Nonetheless, despite its literary defects, Roofs of Ecology is an extremely useful source of information about the many scientific contributions that make up the prehistory of ecology.