Abstract and Keywords
Despite their relative small number, compared with other insects, dragonflies and damselflies have been extensively used as study subjects in ecological and evolutionary research. The few books on these organisms, however, have been more interested in the animals per se than in the scientific questions where they have been used as study subjects. This is the essence of this book: to show how these animals have been used to answer questions and have thus helped to construct ecological and evolutionary theory.
Fifteen years ago, the time when I started thinking about possible ideas to develop for my university degree dissertation, I became fascinated by the flying damselfly and dragonfly adults I found during my field trips to the riverine areas around Xalapa, my hometown in Mexico. I must admit that although this inclination was influenced initially by my like for these animals, I soon realized I was on the right path in using them to test important theoretical questions in ecology and evolution. I was lucky not only because much information was already known about them but also because important advancements could still be achieved with relatively little money and time. In a way, I found out that I could make a scientific career by using these animals, and realizing this at a young age was valuable. Paradoxically, given the considerable amount of information already published, I wondered why there was no single textbook summarizing the scientific discoveries and advancements using damselflies and dragonflies as study animals while similar treatises were available for other taxa (e.g. Bourke and Franks 1995, Field 2001). This feeling started because it was easy to see that odonates had been and are still used to test several theories and hypotheses, and have therefore become ancillary pieces in the construction of ecological and evolutionary theory. Take as an example the fundamental discovery of a copulating damselfly male being able to displace the previous male's sperm from the female vagina, by Waage (1979), an idea that provided important grounds for sperm competition theory, and which fostered research on similar morphological and physiological adaptations in other taxa (Simmons 2001). Although a few books on odonate ecology and evolution were available or have appeared lately (e.g. Corbet 1999), they have overemphasized the fascination of these animals as study subjects without admitting their limitations. The idea of the book I had in mind was to fill two gaps: first, to take a theory-based perspective rather than a taxon-based approach, where enquiry was the prevailing thread for reasoning; and, second, to show the merits of the subject as well as its limitations. The present book was written in this spirit, which is why, to my knowledge, it is different from other odonate books.
Odonates have been prime subjects for research in recent decades. One way of testifying this is by checking the number of recent papers on ecology and evolution where odonates have figured. I carried out this inspection by looking at those cases where these animals have been used as the main research subject. For this I searched in some of the most prominent ecology and evolution journals from the last 14 years. I intentionally did not examine applied journals (such as medical and agronomical) that would not utilize odonates, given their restricted relevance in human affairs. Furthermore, I only selected the numbers of the most widely used insect orders. The results appear in Figure 1.1. As can be observed, and although the absolute numbers are not impressive, odonates have a respectable and regular (in terms of time) place in ecology and evolution disciplines when compared with other insect orders. This despite the astonishingly low diversity of the Odonata compared with, for example, Coleoptera, Diptera, and Lepidoptera, which are some of the most diverse orders in the Animal Kingdom. The contribution that odonates have made to evolution and ecology disciplines (as will also be corroborated in the following chapters) (p.2)
In planning this book, I sought to invite those people to contribute whose efforts have been essential in testing and constructing new ideas. These researchers could directly provide a more straightforward understanding of their discoveries and outline the issues to be addressed in the future. I have encouraged these colleagues to base their writing on theories and hypotheses, and to allow readers to see the pros and cons of using odonates as study subjects, so that we do not appear too optimistic. Readers, I hope, will find this balance in most chapters. As for the subject matter, I tried to gather together the major theoretical and applied topics in which odonates have played a prominent role. Although I have discussed this with other colleagues, I take any blame for any possible bias in these topics and any that have been omitted. If this project proves to be successful, I will include those other topics in future editions. Readers will find two arbitrary sections in this book: ecology and evolution. Of course, the border between these sections is blurred for many chapters and better justice would have been served to include them in a major section called evolutionary ecology. However, as this does not apply to all chapters, I preferred to stick to my arbitrary but still useful resolution. Each chapter had a word limit and was sent out for review, a painful process for everyone (p.3) but especially the editor. My sincere thanks and, particularly, apologies to everyone—authors and reviewers mainly—for my messages that flooded their e-mail accounts. Although they accepted my requests quite happily without exception, there were times at which I imagined that reading my name had a frightening effect on some of these people.
This project started a year and half ago and included far more people than I initially thought. I am very grateful to Brad Anholt, Wolf Blanckerhorn, Andrea Carchini, Andreas Chovanec, Adolfo Cordero-Rivera, Phil Crowley, Hugh Dingle, Henry Dumont, Roland Ennos, Mark Forbes, Rosser Garrison, Greg Grether, John Hafernik, Richard Harrington, Paula Harrison, Frank Johansson, Vincent Kalkman, Walter Koenig, Shannon McCauley, James Marden, Andreas Martens, Mike May, Soren Nylin, Beat Oertli, Stewart Plaistow, Andy Rehn, Mike Ritchie, Richard Rowe, Albrecht Schulte-Hostedde, Laura Sirot, Robby Stoks, Jukka Suhonen, John Trueman, Karim Vahed, Steven Vamosi, Hans Van Dyck, Hans Van Gossum, Rudolf Volker, and Robin Wootton, who gracefully assisted me when reviewing the different chapters, on some occasions reviewing more than one chapter or reading the same chapter more than once. I thank Blackwell Publishing, Chicago University Press, Elsevier, the Royal Society, and Scientific Publishers for allowing to use some figures. Erland R. Nielsen was very generous in giving me free access to use his fantastic pictures. During this winding path, I was gracefully assisted by Raül I. Martínez Becerril, my laboratory technician. The chief of my department, Daniel Piñero, was very encouraging by allowing me not to be in my work place on many days when I was working at home. My graduate and postgraduate students also deserve a place during the more hysterical moments of this project, for understanding my hurry in attending to their experiments and theses. Helen Eaton and Ian Sherman from Oxford University Press were outstanding in providing help during all stages, including editorial and personal situations that arose during these months. Finally, the long nights and early mornings would have been far harder had I not been accompanied by Ana E. Gutiérrez Cabrera. She, more than anyone, suffered this book by taking good care of me and acted as the great loving partner that she has always been. Her company and words were the most gratifying formula each day.
Bourke, A.F.G. and Franks, N.R. (1995) Social Evolution in Ants. Princeton University Press, Princeton, NJ.
Corbet, P.S. (1999) Dragonflies: Behavior and Ecology of Odonata. Comstock Publishing Associates, Cornell University Press. Ithaca, NY.
Field, L.H. (ed.) (2001) The Biology of Wetas, King Crickets and their Allies. CABI Publishing, Wallingford.
Simmons, L. (2001) Sperm Competition and its Evolutionary Consequences in the Insects. Princeton University Press, Princeton, NJ.