estimates of efficiency, it was concluded thatelastic mechanisms must operate. Unfortu-nately, it has not been clear how high an effi-ciency is plausible, and there have been nosatisfactory calculations of energy savingsbased on measurements of the elastic prop-erties of the thorax. An inspired new tech-nique is needed to advance our knowledge,but ‘work loop’ experiments have madeimportant steps in the right direction. Inthese muscles are stimulated while beingstretched and allowed to shorten at rates thatsimulate the action of flight.

Robert Dudley has written a remarkablycomprehensive account of our knowledge ofinsect flight: his bibliography fills 102 pages.No other recent book covers the field so fully,so this one will be most valuable to studentsand researchers. But his aim seems to havebeen to inform rather than to teach. Thebook reads like a series of review articles onthe morphology, evolution, aerodynamics,physiology and control of flight. There areremarkably few illustrations and too littlemathematics. There is frustratingly littledetail about the methods and results of eventhe most significant experiments. However,he has tried to help by providing chaptersummaries, a list of symbols and a glossary.

Dmitry Grodnitsky has written a book ofmuch narrower scope, with far more experi-mental and morphological detail. It startswith the experiments in which he and his col-leagues visualized the air movements in thewake of tethered insects beating their wingsin still air. Observations on free flight wouldhave been preferable, had they been feasible,but these demonstrations of vortex structureare nevertheless valuable. The book contin-ues with discussions of the evolution ofinsect flight, of the functional morphologyof the veins and folds of insect wings, and ofthe scales on the wings of butterflies andmoths. This is a book for specialists. ■

R. McNeill Alexander is in the School of Biology,University of Leeds, Leeds LS2 9JT, UK.

We learn that Sigmund Freud was not awell man (he suffered from chronic fatigueand nervousness, and was enthusiasticabout cocaine); that the term ‘mesmerism’was derived from Viennese physician FranzMesmer, who attributed powers to a forcecalled animal magnetism; that BenjaminFranklin headed a commission which con-cluded that such a force did not exist; andthat for better sex one should try the daytimeor early evening. In the chapter on sex andsleep, Brown even discusses life in the scien-tific community. Discoveries such as that ofnitric oxide as a signal transmitter create a“wave of interest in the scientific commun-ity”; if you succeed in getting on to the waveof discovery, your career starts to flourish.

A 58-page appendix, “The story of livingenergy”, does not meet the objective stated inthe introduction as giving the backgroundideas in bioenergetics. Instead, it is anelegant historical account of how an under-standing of life’s processes has beenacquired, from the insights of ancient Greeceto the recognition that fermentation is afunction of living cells. Readers are exposedto such novelties as the type of healthyregime Socrates might have prescribed.

The very wide range of topics Brown con-siders, and his slight tendency to wander andrepeat himself, do not detract importantlyfrom this informative and enjoyable accountof the scientific basis of our everyday life and behaviour. ■

Paul D. Boyer is in the Department of Chemistryand Biochemistry, University of California, Los Angeles, California 90095, USA.

book reviews

18 NATURE | VOL 405 | 4 MAY 2000 | www.nature.com

The Unnatural Nature of Scienceby Lewis WolpertFaber & Faber, £8.99

Living with our Genes: Why TheyMatter More Than You Thinkby Dean Hamer & Peter CopelandPan, £6.99

Hermaphrodites and the MedicalInvention of Sexby Alice Domurat DregerHarvard University Press, £10.50, $16.95“Ignore the somewhat trendy title, which mightseem to threaten yet another piece of pretentiouspostmodernism. This is a well-researched, soberhistory of a problem that Alice Dreger shows hasdirectly affected more people than we mightthink and which shapes the sense of sexualidentity of us all … Dreger shows how deeplyingrained are our assumptions about gendernormality (sexual anatomy is destiny), and onhow flimsy a basis they have been grounded. Thebook offers us all a lesson in self-awareness.” RoyPorter, Nature 393, 323 (1998)

New in paperback

field of bioenergetics and is well served by hisbroad knowledge and historical perspective.His introductory descriptions of how livingprocesses are made possible by the won-drous machinery of the cell are what I wouldlike to give my non-scientific friends who askwhat my work is about. Avoiding technicaldetails, he describes such processes as howDNA is a blueprint for some 50,000 proteinsthat make possible the occurrence, controland complexity of metabolic pathways, andthat energy is captured in the structure of amolecule called ATP.

In a chapter on “The body electric”, how-ever, he appears over-enthusiastic in the useof the term ‘electricity’, including not onlythe transfer of electrons, but also the use ofproton and sodium gradients as proton andsodium electricity and the use of ATP asphosphate electricity. Most bioenergeticistswould feel the statement “Our cells are ener-gized by huge electric fields driving currentsof charged particles via a myriad minusculewires” does not convey a proper perspective.

Brown is writing for a general audience,though even graduate students in biochem-istry would enjoy his historical accounts ofthe development of current understandingin such areas as glycolysis, the electron-transport chain, the capture of energy bydevelopment of electrochemical proton gra-dients, and the use of phosphate-bond ener-gy. Other nuggets scattered throughout thebook will interest and entertain readers inthe fields of bioenergetics and biochemistry.

Mitochondria, the cellular organelles inwhich ATP is made, were introduced intoour cells billions of years ago by fusion with amicroorganism. It is from these organellesthat free radicals escape and damage ourDNA and proteins, eventually leading toageing. As Brown emphasizes, a wanderinglone electron may wreak havoc with hun-dreds of molecules. Although antioxidantsdo play a preventive role, he inappropriatelyimplies that purified vitamins C and E andbeta-carotene are less effective than naturalantioxidants. It is the structure, not a ‘natur-al’ source, that is important. The tendency ofmitochondria to leak protons and radicals isregarded as a fault in nature’s design. Butanother view is that they are a splendidlyhoned organelle that captures most of theenergy released by use of toxic oxygen, withenough preventive and repair mechanismsto allow us to reach old age.

Brown ranges widely, from motion tometabolic rate and on to obesity, includingchapters on mind energy, brain waves, andsex and sleep. He recognizes that social,psychological and neurophysiological fac-tors all play a role in the pace of life. (I learnedthat giving rats a shot of adrenaline rightafter a learning experience increases memo-ry retention.) We can all relate his good dis-cussion of the effect of stress on metabolismand behaviour to our own experiences.

Strolling through thebioenergy fieldThe Energy of Lifeby Guy BrownFree Press: 2000. 288 pp. $25, £16.99

Paul D. Boyer

Guy Brown defines energy loosely. “We havemany words to express the high energy state:vitality, vigor, vivacity, strength, arousal,ardor, drive, fervor, stamina, gumption, zealand zest,” he states. Such a definition allowsthe author to explore the basis of manyaspects of human behaviour in this unusualand readable book.

Brown is a respected researcher in the

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