Darwin's fishes: Darwin's Fishes: An Encyclopedia of Ichthyology, Ecology and Evolution, by Daniel Pauly. Cambridge University Press, 2004. £55.00 hbk (359 pages) ISBN 0 521 82777 9

View Large Image | Download PowerPoint SlideAs a fish evolutionary biologist but an infrequent reader of Darwin, I never thought that he studied fishes. I was wrong. During the voyage of the Beagle, Darwin made a special effort to collect new fish species and made careful color notes about them. Rather th an gathering his ichthyological information into a monograph, however, he used fish examples throughout The Origin of Species, and fish form major sections in two of his later evolution books. Darwin's fish collections were given to Leonard Jenyns for taxonomic description in Zoology, the four-volume set Darwin edited to describe the animals that he collected during the voyage of the Beagle. Pauly contends that, if Darwin had gathered his knowledge of fishes into a monograph, as he had done with orchids, for example, the influence of fish on his thinking and his contributions to ichthyology would be conspicuous.I was initially baffled by how an alphabetical listing of a heterogeneous set of items could accomplish its author's goal of establishing ‘Darwin's relationship to ichthyology, both as a user of, and a contributor to, the insights of that discipline’. This listing includes people, books, places that Darwin visited, his notes, and institutions with which he dealt. It also includes diverse biological subjects: fish groups, fish habitats, organisms that interact with fish, phenomena and anatomical structures of fishes, concepts, and practices (e.g. lumping taxa). What's the connection? This listing highlights ‘all that CD [Charles Darwin] ever wrote on fishes’. Now we know what it contains, but how does one use this huge alphabetical list?Fortunately, this curious volume comes with a user's manual, ‘Darwin's Fishes: a dry run’, which should not be ignored. In short, the book is a collection of alphabetized entries and annotated references. When an entry is mentioned within the text of another entry, it is marked with an asterisk. References are cited in the usual author and date style. Starting at an arbitrary point in the listing, the reader can move among related topics.So, I gave it a try. ‘Punctuated equilibrium’ caught my eye. What did that have to do with Darwin? Pauly contrasts punctuated equilibrium with Darwin's expectation that natural selection should cause gradual change in the fossil record. Next, he contrasts high evolutionary rates in extant populations with stasis in the fossil record and proposes a resolution to this paradox. Short-term, cyclical, environmental change should cause high short-term evolutionary rates in opposing directions, which cancel each other out to produce long-term stasis. This resolution leads to an extended tangent on the alternation of El Nino and La Nina conditions and their potential impact on the divergence of Darwin's finches. Finally, Pauly contrasts the expectations for evolution in a cyclically changing environment with Van Valen's Red Queen Hypothesis [1xA new evolutionary law. Van Valen, I. Evol. Theory. 1973; 1: 1–30See all References[1]. We are led along a tortuous route in this entry. Lyell, evolution, natural selection, Darwin's finches, missing links, fossil record, taphonomy, Peru, Peruvian anchovetta, phytoplankton-feeding, zooplankton feeding, guppies, and sexual selection are marked with asterisks, but the Red Queen Hypothesis is not.I chose taphonomy, the study of processes by which organisms become fossils, from the marked words. It has two connections to Darwin. Many taphonomic processes are geological, and Darwin was an important geologist. Pauly lists taphonomic questions posed by Darwin in a letter. However, he fails to note here that Chapter 9 of the Origin of Species, ‘On the Imperfection of the Geological Record’, is an extended argument that stasis in the fossil record is a taphonomic artifact. The only word marked with an asterisk in the taphonomy entry was ‘fossil record’, but enough paleontology. Ah, ‘Tahiti’ is the preceding entry, and I was ready to travel. What does Tahiti have to do with Darwin?This is an engaging book for evolutionary biologists and ichthyologists. It establishes that Darwin had ichthyological interests, but it is not a book that you must have to understand evolution or ichthyology. It is Pauly's stream of consciousness compiled in alphabetical order. The reader can create his or her own stream of consciousness by following the asterisks and turning to the literature citations. I did not notice inaccuracies but might have added some entries. However, this is an entertaining book with useful details that can be used to enliven a lecture.