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Enthusiasm for insects and scorpions
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principles, which are described both verbally and as mathematical models. So what are the principal conclusions of the book? First, construction is usually blind, in the sense that there is no architect directing the creation of a structure. Patterns emerge as a consequence of local interactions among players that have only local information. Second, the book emphasizes the importance of positive feedback in generating heterogeneity by amplifying small fluctuations. Thus, positive feedback underlies the recruitment of ants and bees to food clumps. An ant or a bee finding food advertises its location to other foragers who, in turn, pass on the news, so that a sizeable foraging force is rapidly focused onto the site. Positive feedback is, however, a coarse device and honeybees have evolved ingenious additional mechanisms that prevent foragers from all locking on to the same source, instead they are distributed over many sources according to the relative value of each source. Positive feedback is also how ants and termites aggregate building materials into heaps. Ants drop their building bricks where a clump already exists and so the clump grows. Again the formation of usefully shaped clumps needs additional guidance mechanisms. Termites entombing their monstrous (Gulliver among the Lilliputians), slug-like, egg-laying (30 000 or more eggs per day) queen are guided by her pheromones to make the royal cell a snug fit for her 7-cm bulk. Tiny Leptothorax ants build a circular wall of sand grains and gravel around their nest. Modelling shows that positive feedback alone will produce disordered heaps rather than an enclosing wall; therefore, some other cue must determine the shape of the wall. A quite different building principle is suggested by the nest-building behaviour of the wasp Polistes. It works through an in-built stack of stimulus-response mechanisms that causes the evolving structure itself to steer the efforts of the building force. The initial construction stage alters the stimulus presented by the growing nest and, consequently, new classes of responses are evoked. A sequence of such changes can guide the building of elaborate structures. The book will appeal and is accessible to biologists of many kinds, from developmental biologists who wish to understand better the algorithms that might be implemented by genetic networks, http://tree.trends.com
TRENDS in Ecology & Evolution Vol.17 No.3 March 2002
to behavioural and population biologists interested in dominance hierarchies or cooperative foraging, and to ingenious theorists looking for new adventures. Thomas Collett School of Biological Sciences, University of Sussex, Brighton, UK BN1 9QG. e-mail: [email protected]
Enthusiasm for insects and scorpions Essential Entomology: An Order-by-Order Introduction by George C. McGavin. Oxford University Press, 2001. £18.99 pbk (vi + 318 pages) ISBN 0 19 850002 5
Scorpion Biology and Research edited by Philip Brownell and Gary Polis. Oxford University Press, 2001. £65.00 hbk (xiv + 431 pages) ISBN 0 19 508434 9
Matching a book’s format and theme with its intended audience can be challenging. In biology, there are two kinds of decision: whether to write a book or to edit a volume with multiple contributions; and whether to pursue a theme that is primarily taxonomic or one that is conceptual. Essential Entomology and Scorpion Biology and Research state the similar aim of enthusing the readers about their respective taxa. Their success in achieving this goal is largely reflected by their choice of format. George McGavin writes that 56% of described living organisms are insects; such a claim might be difficult to substantiate definitively because there are numerous species awaiting formal description. But it is hard not to be impressed by such a diverse and dominant taxonomic group; moths that feed on mammalian blood, flies that breed in pools of crude petroleum, lice that live exclusively in the throat passages of certain cormorants and pelicans. Essential Entomology describes these and other curiosities in a highly accessible, fascinating and clear order-by-order
151
account. This is an invaluable resource for both student entomologists and other biologists whose research might occasionally involve insects. The key reading lists that conclude the descriptions of each order also provide clues about the relative contributions of different orders to more general biological questions. Scorpions form a comparatively modest part of the global biodiversity, with ~1260 species, representing <2% of the arachnids (which account for 4.5% of living organisms). Scorpion Biology and Research, edited by Philip Brownell and the late Gary Polis, provides a comprehensive review of what we know about these extraordinary animals. And they do have impressive attributes: the remarkable ability to fluoresce brightly when illuminated by UV light; near lethal venoms; and an unusual resistance to ionizing radiation. The choice of chapters is eclectic and mostly reflects the authors’ particular expertise rather than conventional fields of biological research. No doubt this volume will be welcomed by scorpion enthusiasts, but its broader appeal is less clear. Like many edited volumes, there are some fascinating chapters among a largely heterogenous collection, but, although a few are broadly accessible, the highly technical style of others will make difficult reading for the nonspecialist. These two books bring into sharp contrast the merits of each format. Scorpion Biology and Research uses a single, fascinating taxon to illustrate advances in biology and encourage more research involving these animals. This is bound to be a difficult task because there are relatively few people studying these comparatively obscure creatures. Essential Entomology draws on an equally fascinating taxon but, surprisingly, the contribution of entomology to solving general biological problems is not obviously stated. There is no doubt that scorpions make remarkable study organisms, but a single integrated account of their biology might have broader appeal. I also imagine that there is a strong case for a multi-authored, edited volume that highlights the major conceptual advances in biology that have been made using insect model systems. Mark A. Elgar Dept of Zoology, University of Melbourne, VIC 3010, Australia. e-mail: [email protected]
principles, which are described both verbally and as mathematical models. So what are the principal conclusions of the book? First, construction is usually blind, in the sense that there is no architect directing the creation of a structure. Patterns emerge as a consequence of local interactions among players that have only local information. Second, the book emphasizes the importance of positive feedback in generating heterogeneity by amplifying small fluctuations. Thus, positive feedback underlies the recruitment of ants and bees to food clumps. An ant or a bee finding food advertises its location to other foragers who, in turn, pass on the news, so that a sizeable foraging force is rapidly focused onto the site. Positive feedback is, however, a coarse device and honeybees have evolved ingenious additional mechanisms that prevent foragers from all locking on to the same source, instead they are distributed over many sources according to the relative value of each source. Positive feedback is also how ants and termites aggregate building materials into heaps. Ants drop their building bricks where a clump already exists and so the clump grows. Again the formation of usefully shaped clumps needs additional guidance mechanisms. Termites entombing their monstrous (Gulliver among the Lilliputians), slug-like, egg-laying (30 000 or more eggs per day) queen are guided by her pheromones to make the royal cell a snug fit for her 7-cm bulk. Tiny Leptothorax ants build a circular wall of sand grains and gravel around their nest. Modelling shows that positive feedback alone will produce disordered heaps rather than an enclosing wall; therefore, some other cue must determine the shape of the wall. A quite different building principle is suggested by the nest-building behaviour of the wasp Polistes. It works through an in-built stack of stimulus-response mechanisms that causes the evolving structure itself to steer the efforts of the building force. The initial construction stage alters the stimulus presented by the growing nest and, consequently, new classes of responses are evoked. A sequence of such changes can guide the building of elaborate structures. The book will appeal and is accessible to biologists of many kinds, from developmental biologists who wish to understand better the algorithms that might be implemented by genetic networks, http://tree.trends.com
TRENDS in Ecology & Evolution Vol.17 No.3 March 2002
to behavioural and population biologists interested in dominance hierarchies or cooperative foraging, and to ingenious theorists looking for new adventures. Thomas Collett School of Biological Sciences, University of Sussex, Brighton, UK BN1 9QG. e-mail: [email protected]
Enthusiasm for insects and scorpions Essential Entomology: An Order-by-Order Introduction by George C. McGavin. Oxford University Press, 2001. £18.99 pbk (vi + 318 pages) ISBN 0 19 850002 5
Scorpion Biology and Research edited by Philip Brownell and Gary Polis. Oxford University Press, 2001. £65.00 hbk (xiv + 431 pages) ISBN 0 19 508434 9
Matching a book’s format and theme with its intended audience can be challenging. In biology, there are two kinds of decision: whether to write a book or to edit a volume with multiple contributions; and whether to pursue a theme that is primarily taxonomic or one that is conceptual. Essential Entomology and Scorpion Biology and Research state the similar aim of enthusing the readers about their respective taxa. Their success in achieving this goal is largely reflected by their choice of format. George McGavin writes that 56% of described living organisms are insects; such a claim might be difficult to substantiate definitively because there are numerous species awaiting formal description. But it is hard not to be impressed by such a diverse and dominant taxonomic group; moths that feed on mammalian blood, flies that breed in pools of crude petroleum, lice that live exclusively in the throat passages of certain cormorants and pelicans. Essential Entomology describes these and other curiosities in a highly accessible, fascinating and clear order-by-order
151
account. This is an invaluable resource for both student entomologists and other biologists whose research might occasionally involve insects. The key reading lists that conclude the descriptions of each order also provide clues about the relative contributions of different orders to more general biological questions. Scorpions form a comparatively modest part of the global biodiversity, with ~1260 species, representing <2% of the arachnids (which account for 4.5% of living organisms). Scorpion Biology and Research, edited by Philip Brownell and the late Gary Polis, provides a comprehensive review of what we know about these extraordinary animals. And they do have impressive attributes: the remarkable ability to fluoresce brightly when illuminated by UV light; near lethal venoms; and an unusual resistance to ionizing radiation. The choice of chapters is eclectic and mostly reflects the authors’ particular expertise rather than conventional fields of biological research. No doubt this volume will be welcomed by scorpion enthusiasts, but its broader appeal is less clear. Like many edited volumes, there are some fascinating chapters among a largely heterogenous collection, but, although a few are broadly accessible, the highly technical style of others will make difficult reading for the nonspecialist. These two books bring into sharp contrast the merits of each format. Scorpion Biology and Research uses a single, fascinating taxon to illustrate advances in biology and encourage more research involving these animals. This is bound to be a difficult task because there are relatively few people studying these comparatively obscure creatures. Essential Entomology draws on an equally fascinating taxon but, surprisingly, the contribution of entomology to solving general biological problems is not obviously stated. There is no doubt that scorpions make remarkable study organisms, but a single integrated account of their biology might have broader appeal. I also imagine that there is a strong case for a multi-authored, edited volume that highlights the major conceptual advances in biology that have been made using insect model systems. Mark A. Elgar Dept of Zoology, University of Melbourne, VIC 3010, Australia. e-mail: [email protected]