The Art of Being a Parasite. Claude Combes, translated by Daniel Simberloff. The University of Chicago Press, Chicago, IL, 2005. 291 pp. $25.00 (0226114384 paper).
Parasitology books are traditionally compendia of the bizarre and macabre-page after page of sinister pathogens infecting obscure hosts and undergoing complex metamorphoses via stages with esoteric names. Combes's book is appropriately replete with these details, covering a wealth of natural history, anatomy, life history and behaviour. What sets this book apart is the way in which this information is presented. Rather than merely catalogued, host-parasite interactions are used to illustrate broad ecological, evolutionary and philosophical discussions. After each chapter, one comes away both with a detailed knowledge of current parasitological research, but also with a deeper and broader grasp of fundamental conceptual issues in the biological sciences generally.
Rather than restricting himself to the usual suspects-nematodes, flukes, trematodes and tapeworms-the reader is presented with an unprecedented breadth of examples. This book is the first parasitology text that considers mitochondria, mycorrhizae and mistletoes; cuckoos, cyanobacteria and chromosomes as worthy examplars of parasitism. Many biologists will be startled to find their study organisms included in a parasitological treatise, and Combes is to be credited for working from such a broad literature base. This breadth makes the emergent generalities and widely supported patterns all the more remarkable. A pertinent example is this passing comment: "this is why we know of no parasite (at least among the multicellular species) that has evolved to become free-living, even if such a passage appears to be theoretically possible", p 34; pointing out that the route to parasitism is necessarily a one-way street.
In addition to novel examples, many case studies are well known-leaf cutting ants and their fungus gardens, Madagascan orchids and their moth pollinators, ungulates and their blood-borne trypanosomes. By incorporating recent findings and drawing comparisons with analogous systems, Combes presents many of these "text-book examples" in a new light, often revealing these interactions to be more convoluted than first thought. Hence, in the review of cuckoos and other nest parasites, we learn that cuckoos do not pick up ectoparasites from their adoptive parents-it is only when they mate in their second year that they acquire lice and mites from conspecifics. Hence, the very act of being a parasite confers a cuckoo immunity to parasitism until maturity. Even the footnotes are replete with parasitological gems: reminding us that the reason prized Woodcock are best consumed whole is to ensure the flavour of "millions of small tapeworms in the genus Amoebotaenia" residing in their intestines infuse the meat during cooking.
A persistent theme throughout the book relates to the two filters or diaphragms defining the evolution of host-parasite systems: the encounter filter and the compatibility filter. Originally introduced in his 1995 book, this theme is well integrated and makes a significant contribution to the conceptual basis of understanding host-parasite interactions. There is a thoughtful clarification of the distinction between virulence and pathogenicity, an excellent précis of the Red Queen Hypothesis and a succinct summary of adaptationism, although he perpetuates the misuse of the term spandrel (c.f. pendentive, after Houston 1990). Closer to home, Combes discusses why humans play host to more parasites than any other species and, far from being merely a sampling artefact, elucidates the many facets of human history, behaviour, distribution and lifestyle that pre-dispose us to infection. This has dramatic consequences for human health and, more surprisingly, the health of our domestic animals. Taenia saginata and T. solium (the beef and pork tapeworms respectively) were both human parasites first, passed horizontally to these animals soon after domestication.
The writing style is accessible, lucid and surprisingly engaging, using occasional anecdotes and asides to punctuate the text. Originally published in French, Daniel Simberloff translated the book into English, and his voice is almost imperceptible-the hallmark of a skilled translator (although I doubt Voltaire would have approved of his satire "Candide" being referred to as a pamphlet!). The French character of the book is still retained-the text is replete with idioms and analogies familiar to francophones. More importantly, Combes cites the French parasitological literature extensively, revealing a wealth of hitherto under-appreciated literature to monolingual researchers.
While I was pleased at the inclusion of a glossary, it was all too brief (four pages) and many terms defined in the text were not included, including the subtle differences between endoparasites and mesoparasites, and the distinction between allomones and kairomones. The book is well illustrated with half-tone diagrams, flow-charts and graphs, all of a consistently high standard, and index is comprehensive.
While the engaging style and uncluttered language make this book accessible to a general audience, this book is aimed squarely at non-parasitologist professional biologists, emphatically underscoring the relevance of parasitology to evolutionary biology and the life sciences generally. Combes demonstrates that there are few, if any clear-cut distinctions between predation, parasitism, commensalism, and mutualism. Rather, they are presented as a continuum, challenging current typological approaches to their study. Any biologist interested in interspecific interactions of any kind should read this book-it will change their view of what is (and isn't) a parasite, broaden their taxonomic horizons and remind them that there is a wealth of primary scientific literature written in other languages awaiting the adventurous explorer.
DAVID M WATSON
Institute for Land, Water and Society
Charles Sturt University
Albury NSW 2640, AUSTRALIA
Houston, A. 1990. Matching, Maximizing and Melioration as Alternative Descriptions of Behaviour. Pages 498-509 in Meyer JA, Wilson S, eds. From Animals to Animats. Cambridge, MA: MIT Press.