"Celebrity sells" is just as much of a truism at zoos as it is at movie theaters. In order to draw crowds and swell coffers, zoos typically give giant pandas, polar bears, tigers, gorillas, and other celebrity creatures the starring roles and cast the lowly, more common critters in minor parts. The approach may be lucrative, but Ron Kagan, director of the Detroit Zoological Institute, believes it gives a skewed view of the animal kingdom. "The real story is not in the big cuddlies— it's in the creepy crawlies," Kagan says. "We have a responsibility to market what's important to nature."
Creepy crawlies are the marquee attraction at the Detroit Zoo's brand new National Amphibian Conservation Center, a $6.1 million, 12,000-square-foot facility that highlights the critical ecological role played by frogs and their cousins— toads, newts, salamanders, and the little-known wormlike caecilians. Amphibians live both on land and in water and are exquisitely sensitive to changes in their habitats. As such they are living barometers of the health of the environment and an early warning system of potential threats to humans. Scientists have noted an alarming drop in amphibian numbers, but no one knows exactly why. Among the theories: chemical pollution, parasitic infections, and increased ultraviolet radiation through ozone holes in the atmosphere.
Located on an island wetland, the amphibian center is housed in a pavilion graced with a sculptured frog trio squirting water at a mechanical fly. Visitors step inside to find a spongy floor in an entryway filled with cool, moist air. Croaks, buzzes, and ribbits emanate from a succession of galleries featuring an astonishing array of amphibians, including Puerto Rican crested toads, South American burrowing caecilians, and Japanese giant salamanders that can weigh 88 pounds and reach four feet in length. A glassed-in pond allows visitors to glimpse amphibian life above and below the waterline of a Michigan wetland, while an ersatz cave thrills children with dripping stalactites and real salamanders. Penetrating farther, visitors enter an immersion gallery that mimics a Peruvian Amazon rain forest, complete with bromeliads, dracaena, tropical figs, and strawberry guavas, and free— roaming smokey jungle frogs, marine toads, ameiva lizards, swallow tanagers, centipedes, millipedes, and giant cockroaches. "Docents tell you to watch your step as you enter the gallery because things literally run across the path in front of you," laughs Kevin Zippel, the center's curator. An occasional drizzle, mist, lightning, and thunder burst add to the experience. "We're competing with television and video games," acknowledges Zippel.
All along the way, exhibits offer engaging instruction. To illustrate the wonders of metamorphosis, a breeding tank features clusters of see-through bullfrog eggs with unhatched tadpoles inside as well as free-swimming tadpoles and mature animals. Other exhibits attest to amphibians' significance in scientific research (they may be a source of potent new antibiotics) and popular culture (the Chinese see a "toad in the moon," the French cook up frogs' legs, and Americans adore Kermit). By the time visitors leave the center, any doubts about amphibians' place on the planet— or in zoos— should have vanished.
Heroes, Rogues, and Lovers: Testosterone and Behavior James McBride Dabbs with Mary Godwin Dabbs McGraw-Hill, $24.95
When James Dabbs was growing up in South Carolina in the 1950s, it was widely understood that, as Katharine Hepburn's missionary schoolmarm instructed Humphrey Bogart's soused riverboat captain in The African Queen, "Nature . . . is what we were put on this earth to rise above!" These days, we're more likely to regard our animal natures with curiosity— leading to a special fascination with testosterone, everyone's favorite hallmark of our bestial past.
Dabbs, now a professor of psychology and head of the social/cognitive psychology program at Georgia State University, has traced our growing interest in testosterone and examined its potent effects on individuals and society. He maintains that the hormone gives us energy, ambition, and daring. Without it, he suggests, we'd be human shrinking violets, too shy to leave the cave and too sluggish to invent the wheel. But testosterone also spawns impulsive crimes and barroom brawls, not to mention idiotic action flicks and leering men's magazines.
Dabbs offers great tidbits about "T," as scientists affectionately call testosterone: While the hormone appears to sharpen our focus and concentration on a single task, it detracts from our ability to attend to several things at once. Although the average guy churns out eight to 10 times as much testosterone as the average woman, female bodies appear to be much more sensitive to small amounts of the hormone. And because testosterone levels fall in men as they age, and rise in women in relation to dropping levels of the female hormone estrogen, the sexes actually become more alike as they age. The information here ranges from the significant (men with high levels of testosterone die younger, perhaps because they do more fighting and risk-taking and less consensus-building) to the quirky (levels of the hormone are lower among vegetarians, possibly because there are natural estrogens in the plants they eat). But all of it is irresistible, especially Dabbs's original research on the varying levels of testosterone found among people in different fields or in different situations. Dabbs is campaigning to get everyone from housewives to drill sergeants to "spit for science"— that is, submit a saliva sample for testosterone testing.
From his data, Dabbs has created a predictable portrait of the high-testosterone man: On average, he's "leaner, balder, more self-confident, more rambunctious, less likely to have friendly smiles, and more likely to favor tattoos and gold jewelry than other men." As we might expect, football players and construction workers are relatively high in testosterone, whereas intellectuals and administrators are relatively low. Firefighters' testosterone rises on the way to a blaze and declines once they're safely away from the fire and headed back to the station.
Such details are so much fun it seems almost churlish to point out that they don't really tell us much. We need to get inside the black box of testosterone and find out exactly how it affects us physiologically before we can talk knowledgeably about the kind of person it produces. Without such critical information, Dabbs's data will remain more intriguing than illuminating. -- Annie Murphy Paul
One Good Turn: A Natural History of the Screwdriver and the Screw Witold Rybczynski Scribner, $22.
When Witold Rybczynski was asked to pen a magazine piece about the best tool of the past millennium, he was stumped. The hammer, auger, saw, drill, and plumb line all turned out to predate the last 1,000 years. More recent innovations, such as power tools, amount to mere laborsaving, incremental improvements. Rybczynski's wife, Shirley, finally came up with a viable candidate: "You always need a screwdriver for something," she told her husband.
In this trim volume, architect and historian Rybczynski engagingly recounts his quest into the origins of the screwdriver and its necessary adjunct, the screw. Indeed, the screw steals the show. The concept of this helical wonder has been with us in some form since the early Greeks, and Rybczynski assiduously tracks its development and use in machinery, armor, and weaponry. By the time he espies perhaps the earliest depiction of a screwdriver— in a medieval rendering of a screw-cutting lathe— it's a bit of an anticlimax.
But the screw's history engrosses right down to its daunting manufacture. As Rybczynski relates, 16th-century screw-making was a cottage industry. The threads, filed by hand, were imperfect and shallow, and screws were so expensive that they were sold individually. In the 18th century, industrialization brought consumers mass-produced screws at cheaper prices, but they still had one drawback: The machinery of the day couldn't file a screw to a point. Workers had to drill a hole into material to get the blunt screw-end started. The familiar machine-made, pointed self-starting screw didn't appear until the mid-19th century.
One of Rybczynski's most absorbing tales is of how the Phillips screwdriver— the one with the cross-slotted head— enabled its corresponding counterpart to beat out the Robertson screw, making the Phillips the world's standard. The Robertson, with an incised square socket on its head, fastens faster and tighter than the Phillips. But car manufacturers preferred the Phillips precisely because of its less-snug fit: The automated screwdrivers on the factory line popped out of the screws' recesses more easily, thus preventing over-torquing. By telling the tale of the screw, Rybcyzinski has done one good turn of his own. -- ÑMargaret Foley
Extinct Humans Ian Tattersall and Jeffrey Schwartz Westview Press, $50.Dawn of Man: The Story of Human Evolution Robin McKie DK Publishing, $30.
Keeping up with the dizzying pace of fossil finds and their impact on theories of human evolution can be difficult these days. These two new books promise to bring you up to speed. Anthropologists Tattersall and Schwartz take a fossil-by-fossil approach to telling the story of our purported ancestors. Science writer McKie covers much the same ground but weaves the paleontologists' tales together in a strong narrative.
Hidden Evidence David Owen Firefly Books, $24.95.
Not for the faint of heart, this book showcases 40 high-profile crimes and the science used to crack them. With the help of lavish (and sometimes grisly) illustrations, Owen discusses everything from matching dental records and DNA to performing autopsies and gas chromatography studies. Once you're finished you'll understand the telltale marks of drowning or bombing, but you won't want to eat for a while.
Bananas: An American History Virginia Scott Jenkins Smithsonian Institution Press, $16.95.
Americans eat an average of 75 bananas a year, yet before 1880 the fruit was almost unknown in this country. In a vivid and often funny history, Jenkins charts how shifting diets and nutritional standards at the turn of the century as well as more recent changes in food marketing and distribution propelled the Caribbean fruit to widespread popularity and iconic stature in American culture
Archimedes' Bathtub: the art and logic of breakthrough thinking David Perkins W. W. Norton and Company, $24.95.
Perkins finds common cognitive principles underlie the innovative thinking of the world's foremost scientists through the ages and offers up puzzles and exercises to hone readers' creativity. By the end of this book, you may not be thinking exactly like Archimedes, but you're sure to be ready to experience your own "Eureka!" moment.
Volcano Cowboys: the Rocky evolution of a dangerous science Dick Thompson St. Martin's Press, $26.95.
Journalist Thompson takes readers on a harrowing ride with the scientists who study the world's most dangerous natural event. Dropping into craters of active volcanoes, they measure gases and monitor seismographs in an effort to predict when eruptions will occur.
Sexing the Parrot: Changing the World With DNA Wilson Hall Cassell, $27.95.
With the Human Genome Project gathering speed, don't be left behind the genetics curve. Hall, a geneticist, uses simple, lively prose to explain the intricacies of DNA developments, including gene therapy and genetically modified food. He also examines their enormous ethical implications. As a bonus, you'll learn how geneticists can now more easily determine the sex of parrots, sparing the birds from invasive (and potentially fatal) endoscopy.
Supersymmetry: Unveiling the Ultimate Laws of Nature Gordon Kane Perseus Publishing, $26.
Particle physicist Kane elegantly makes the case for a theory that, if confirmed, could alter our understanding of how matter works. Supersymmetry posits that every particle has a "superpartner" that can be detected only when the two are smashed together at very high energy levels. Quarks have "squarks," electrons have "selectrons," and so on. Kane guides us through this often bewildering subatomic world and its implications. A glossary helps readers who have trouble telling a muon from a gluon.
The Eighth Continent: Life, Death, and Discovery in the Lost World of Madagascar Peter Tyson William Morrow, $27.50.
Part field report, part travelogue, part ecological history, Tyson's book is an engrossing testament to one of the planet's most astonishing places. His tales from the field, by turns moving and hilarious, are interwoven with descriptions of the island's bizarre wildlifeÑfrom screaming geckos to upside-down treesÑand their uncertain future at the hands of the Malagasy, who are desperate for fuel wood and farmland. Read this book to get a sense of what future generations may be missing.
Stinging Trees and Wait-A-Whiles: Confessions of a Rainforest Biologist William Laurance University of Chicago Press, $25. For an unusually candid look at the tribulations of fieldwork, pick up ecologist Laurance's firsthand account of his 18 months in northeastern Australia's fragmented tropical rain forest. The ardent conservationist must contend with hostile loggers as well as suspicious farmers, unruly volunteers, and resistant government officials.
Henry Norris Russell: Dean of American Astronomers David H. DeVorkin Princeton University Press, $49.50.
Known as "the General," Henry Norris Russell transformed American astronomy from a simple observation of the stars into a quest to understand the origins of the universe. This meticulous, scholarly biography traces Russell's development into an innovative astrophysicist even as he clung fiercely to his Presbyterian faith. -- Compiled by Eric Powell
To get a taste of the sounds and sights of the Detroit Zoo's amphibian exhibit, visit www.detroitzoo.org