News this Week

Science  19 Jan 2001:
Vol. 291, Issue 5503, pp. 408
  1. GRADUATE EDUCATION

    Student Survey Highlights Mismatch of Training, Goals

    1. Jeffrey Mervis

    Biochemist Timothy Dore is living his dream. After earning his Ph.D. from Stanford University in 1998 and doing a postdoc at the University of California, San Diego, Dore began a tenure-track job last fall at a major research university.

    But fewer and fewer of his colleagues can say the same. A new report, based on a survey of U.S. graduate students, finds a “three-way mismatch between student goals, their training, and their actual careers.” It recommends major changes to better prepare graduate students for today's economic realities, including a greater emphasis on teaching, more information about the job market, and support for those interested in nonacademic career paths. Educators hope it will spur efforts to reform a system that Dore, who is also a co-author, had to navigate largely on his own.

    “I learned to be a faculty member despite the system,” says Dore, a 33-year-old assistant professor of chemistry at the University of Georgia, Athens, who teamed with education policy analyst Chris Golde of the University of Wisconsin, Madison, on a survey of 4114 graduate students in 11 disciplines from 27 institutions. “I decided early on that I was interested both in good teaching and good research, and went looking for the help I needed. I had to make it happen.”

    The study, funded by Pew Charitable Trusts and released this week (www.phd-survey.org), feeds into a growing debate about doctoral education in the higher education community by adding the voice of students. The title delivers the message: “At Cross Purposes: What the experiences of today's doctoral students reveal about doctoral education.” Citing other studies, it drives home the point that the path taken by Dore is no longer the norm: Almost half of U.S. faculty members are part-timers, nearly one-third work at 2-year colleges, and only one-quarter of full-time faculty members work at research universities. And it makes a number of recommendations, including providing more relevant information for students about their training and what happens to graduates, better mentoring by faculty, more emphasis on teaching, more courses outside one's field, and more discussion of the problem at professional meetings.

    “This report not only provides a comprehensive overview of how students feel, but it also suggests what various groups can do,” says George Walker, dean of the graduate school at Indiana University, Bloomington, who this month is beginning an initiative on graduate education as senior scholar at the Carnegie Foundation for the Advancement of Teaching. “We're going to pick a few disciplines and focus on leading universities, and this report will be a very valuable reference guide.”

    The mismatch between training and reality persists, says Golde, because of the “incredible conservatism of higher education” and the fact that professors who have thrived under the current system have little incentive to change it. Another obstacle to reform, says Jerry Gaff, vice president of the Association of American Colleges and Universities (AACU), is the fragmented structure of U.S. graduate education itself. “It's a cottage industry,” he says, with most of the authority vested in individual faculty members and “with little consistency across departments and universities.”

    The survey, conducted by mail and over the Web with a 42% response rate, contains good news along with the warnings. Only 3% of the students regret their decision to attend graduate school, and some 91% say that they like their adviser. An even higher percentage, topped by chemistry students at 96%, say that they understand what's required of them for a Ph.D. And seven in 10 say that their program has prepared them well to become independent researchers. Dore says his experience supports those results: “In research I succeeded because of the system, thanks to an adviser telling me what I needed to know.”

    The problem, however, is that most graduates need more than that to compete in today's economy. “I don't think the old model of training researchers is sufficient anymore,” says Gaff. “If students only learn topflight research skills, they won't get jobs when they graduate.” Students say that they are not well prepared for classroom responsibilities, especially teaching higher level courses. They also would like to take more courses in related fields and outside their disciplines, such as languages and business. Their training in professional practices is also inadequate, the students report, with large numbers unclear about subjects ranging from assigning authorship on papers to avoiding financial and ethical conflicts of interest.

    The authors admit that neither their findings nor their recommendations will surprise those who have followed the debate for the past decade, although they hope the data will arm reformers like Walker. In addition to putting up $350,000 for the study, Pew is a partner with AACU and the Council of Graduate Schools in the Preparing Future Faculty project, a national effort to improve graduate training (www.preparing-faculty.org). This summer, the National Association of Graduate-Professional Students hopes to present the results of a similar survey organized around departments. Its goal is to help “consumers” select the graduate program that's best for them.

    Students may indeed be the strongest force for change. This survey, for example, arose from a graduate course in academic ethics that Dore and Golde took at Stanford University. Dore has taken that interest with him to Georgia, where he is designing small organic molecules as probes to better understand the workings of the cell. “My future on the tenure track is tied to this project as well as to my research,” he says about his plans to further analyze the survey's large database. “And my department chair and the graduate school dean are very interested in what I come up with.”

  2. ENDANGERED SPECIES

    Cloned Gaur a Short-Lived Success

    1. Gretchen Vogel

    The first clone of an endangered species died last week, 2 days after its birth on 8 January. The baby gaur—a wild ox native to Southeast Asia—seemed healthy at birth but a day later developed a typically fatal bacterial infection that can plague young calves. The death “appears to be totally unrelated” to the cloning procedures, says Robert Lanza, vice president of Advanced Cell Technology (ACT) in Worcester, Massachusetts, the company that sponsored the project. ACT is ready to try again with gaur and other endangered animals, Lanza says.

    Scientists at ACT produced the animal, named Noah, by fusing skin cells from a male gaur with cow eggs from which the nucleus had been removed. Forty-four embryos were then transferred into 32 surrogate mother cows at Trans Ova Genetics in Sioux Center, Iowa. Eight pregnancies resulted, five of which ended in miscarriage—common in cloning—and two fetuses were removed early for tissue examination. In October, the scientists reported that the fetuses seemed to be developing normally. That left Bessie with her calf, Noah, who was originally scheduled to be born by cesarean section in November. Shortly before the original due date the scientists learned that gaur gestation is longer than they thought and postponed the birth until last week.

    Many of the animals cloned to date have had serious health problems at or shortly after birth, including lung defects. Some have also been born abnormally large. But Noah, weighing in at 36 kg, initially received a clean bill of health. The C-section went smoothly, says Philip Damiani of ACT, and veterinarians who examined the newborn rated him in the top 3% of newborn cloned calves based on his alertness, eagerness to feed, and other factors. Within 12 hours, Damiani says, Noah was beginning to walk—a sign that he was strong and not oversized.

    But about 24 hours after his birth, Noah developed diarrhea, often called scours. Doctors immediately suspected Clostridium perfringens, a bacterium that is normally found in the intestines of cattle. It can overgrow in young animals and produce a deadly toxin. Veterinarians treated Noah with antibiotics and an antitoxin. Despite these efforts, he died the next day. Clostridial infections are not uncommon in newborn calves, says veterinary infectious disease expert Robert Holland of Iowa State University in Ames, but are unusual in animals delivered by C-section. Damiani says the team is working to trace the source of the bacteria. A “control calf” fed the same colostrum and kept under the same conditions as Noah is doing fine, he says.

    After such promising initial signs, “to lose him to scours is devastating,” Damiani says. “When I left on Tuesday, he was walking around and even being a bit difficult to handle.”

    The death has not derailed the company's program to clone endangered animals. They plan to try again with a gaur, says Damiani. And Lanza says that within a few months the company will embark on a project to clone the bucardo, a Spanish mountain goat, from cells taken from the last living member of the species. The bucardo project should be both faster and easier than the gaur, as researchers have had more success with cloning goats and the animals' gestation period is only 5 months as opposed to 10 for a gaur. Predicts Lanza: “We could have live kids by end of summer or early fall.”

  3. ASTRONOMY

    Weird New Exoplanets Leave Theory Behind

    1. Govert Schilling
    1. Govert Schilling is an astronomy writer in Utrecht, the Netherlands.

    SAN DIEGO—Now that astronomers have found planets orbiting some 50 sunlike stars, you might think they have seen everything. Far from it. The latest pair of extrasolar systems, which a prolific U.S. team of planet hunters unveiled at a conference here last week,* jolted even the most jaded onlookers.

    “After finding so many exoplanets, we thought we understood their masses and orbits,” says team leader Geoffrey Marcy of the University of California (UC), Berkeley. “Maybe we became a little cocky. But the new systems, with two planets each, are unique and a little frightening. These systems stump us.”

    The first of the cosmic puzzlers belong to a dim dwarf star known as Gliese 876, just 15 light-years from Earth in the constellation Aquarius. Two planets are waltzing around the star in lockstep, the inner one completing two orbits as the outer one circles the star once. Computer simulations by Hal Levison of the Southwest Research Institute in Boulder, Colorado, indicate that planetary resonances are fairly common. “We encounter them in 25% of all cases,” Levison says. In our own solar system, in fact, Pluto and Neptune share a 3:2 resonance, while three of the four large satellites of Jupiter display a 4:2:1 resonance. What makes Gliese 876 different is that it is poised on the brink of instability. Calculations by Jack Lissauer of NASA's Ames Research Center in Moffett Field, California, show that a slight change in masses or orbits would cause the planets to fly into their star or out into space. The near-instability suggests that the system may have had a turbulent history, although the details are still unclear.

    “It's a very exciting discovery, with profound theoretical implications,” says theorist Douglas Lin of UC Santa Cruz. Lin suspects that the system once contained more planets in larger orbits. Gravitational interactions with the gaseous disk from which they formed then caused the planets to slowly spiral inward. Some of the planets may have been flung into outer space; the remaining two became locked into the mutual resonance.

    While theorists may scratch their heads over resonance, it's the second discovery that really has them flabbergasted. It's a humongous gaseous planet, at least 17 times more massive than Jupiter. “We've never seen anything like this before,” says team member Paul Butler of the Carnegie Institution of Washington. “This is a whopper.”

    The Goliath planet orbits a sunlike star known as HD 168443, 123 light-years from Earth in the constellation Serpens. In 1998, Marcy's team found another planet, weighing at least 7.7 Jupiter masses and circling the star every 58 days at an average distance of just 45 million kilometers. The new giant orbits the star every 4.8 years at an average distance of 410 million kilometers, almost three times the distance between Earth and the sun.

    The “whopper planet” is clearly too massive to be a normal planet, Marcy says. Most astronomers agree that planets form in a swirling disk of gas and dust surrounding a nascent star. In Levison's computer simulations, however, planets forming in such disks never grow more massive than 8 to 10 Jupiters before sweeping their surroundings clean. Larger objects can form outside disks, but above 13 Jupiter masses or so, the core of a gas ball becomes so hot and dense that deuterium (heavy hydrogen) starts to burn, turning the object into a failed star, or brown dwarf.

    But that label doesn't quite fit, either, says Butler: “Calling this object a brown dwarf means you're sweeping all of the mysteries under the rug.” Brown dwarfs, he points out, are thought to form directly from collapsing clouds of interstellar gas. That couldn't happen so close to the parent star. Moreover, HD 168443's other companion, a planet, presumably formed in an accretion disk. No one understands how both processes could occur together.

    A few astrophysicists suspect the new finds may be less mysterious than they appear. David Black of the Lunar and Planetary Institute in Houston, Texas, an outspoken exoplanet skeptic, points out that the technique Marcy's team uses to find exoplanets—deducing their gravitational pull on the star from Doppler shifts in the star's light—likely underestimates the planets' masses. The more an object's orbit is tilted with respect to Earth, the smaller the shifts. As a result, Black says, both objects orbiting HD 168443 could be low-mass stars instead of planets or brown dwarfs. “There are plenty of [triple star] systems like this,” says Black.

    But none of the thousands of triple star systems known has all three members within a few hundred million kilometers of one another, Butler notes. Besides, he says, if the mystery object were a dwarf star, the European Hipparcos satellite would see HD 168443 wobbling slightly because of the orbiting object's gravitational pull. The absence of sideways motion, Butler says, means that the object can't be more massive than 40 Jupiter masses—well within brown dwarf territory.

    The new discoveries show how little astronomers know about the formation of planetary systems, Marcy says. Yet the data should help scientists test their models and weed out the unfit. “I regard these discoveries as our gift to the theorists,” says Butler. Lin, for one, is a grateful recipient. “I lose sleep over this,” he says, “but I'm very happy, because these results will keep me busy.”

    • * American Astronomical Society, 197th meeting, 7-11 January

  4. EVOLUTIONARY GENETICS

    Horses Domesticated Multiple Times

    1. Elizabeth Pennisi

    For several millennia, horses have been lending a hoof to humans. But despite extensive archaeological excavations, researchers have not been able to pin down the exact history of where and when these animals were domesticated. Now, on page 474, evolutionary geneticist Carles Vilà and Hans Ellegren of Uppsala University in Sweden and their colleagues present new genetic evidence on how wild horses came to be beasts of burden. Contrary to conventional wisdom, explains Ellegren, head of the Uppsala lab, “in many places over the world, people must have independently started to domesticate their local horses.”

    Many horse lovers and researchers have long traced their steeds' ancestry back to the grassland steppes of Eurasia, in the vicinity of the current Ukraine, Kazakhstan, and Mongolia. There, horses hunted as food were eventually tamed, fueling the expansion of their masters and, consequently, the domesticated horse across most of Europe.

    Not everyone accepts that scenario, however. Archaeological evidence from that time, some 5000 years ago, is difficult to interpret. Horse bones unearthed at archaeological sites could just as easily reflect a horse-meat diet as a horse-riding or horse- breeding culture. Some researchers have examined fossils and found telltale signs, such as horse teeth worn down by a bit. Yet even with these data, “we've had a big problem with [understanding] horse domestication,” says Sandra Olsen, an archaeologist at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.

    While Vilà was a postdoc in Ellegren's lab in 1998, the two realized they might be able to pinpoint the origins of domestication by tracing the genetic lineages of different breeds of modern horses and comparing those lineages to DNA collected from ancient horse fossils. They first focused on mitochondrial DNA (mtDNA), genetic material inherited only from the mother, because mutations there accumulate fast enough to reveal some insight into the breeding history of these animals in recent millennia.

    If horses had been domesticated once from a limited number of ancestors, the mtDNA of all modern domesticated horses should look basically alike. Essentially, the horse family tree would branch off when domesticated horses diverged some 5000 years ago; the small variations among modern horses could be represented as twigs coming off that one branch. By contrast, most DNA from truly wild horses (not the feral horses that roam free today) would belong on other branches.

    To probe the puzzle, the Uppsala researchers compiled a database that provides “a good blueprint of the diversity of different horse types,” says Ellegren. They had ready access to blood samples from a Swedish registry of 191 pedigree horses, including primitive English and Swedish animals and one breed derived from animals imported to Iceland by the Vikings. Vilà and colleagues then acquired DNA samples from one Przewalski's horse, a small Mongolian equine thought by some to be a sister species to the original wild horses. The team also obtained DNA from the leg bones of horses that have been preserved in the Alaskan permafrost for more than 12,000 years. Another eight samples came from 1000- to 2000-year-old archaeological sites in southern Sweden and Estonia. The study is unique, Ellegren says, “in that we combined an analysis of modern horses and ancient horses.”

    Similar DNA analyses for cattle, sheep, water buffalo, and pig indicate that those modern livestock derived from a small number of animals domesticated in just a few places 8000 to 10,000 years ago. That's because today's animals are much less genetically diverse than their ancient forebears. The mtDNA in today's pigs, for instance, falls into a few distinct groups, suggesting that the offspring of the original livestock were traded and used to establish herds elsewhere.

    But the horse mtDNA tells a different story. To the researchers' surprise, the mtDNA samples from the modern horses showed almost as much genetic variation as did samples from the fossil horses—and no distinct branches as there are in domesticated pigs or cattle. The genetic diversity in modern horses implies “that the domestication of the horse was different in time, place, and process from that of other animals,” says Daniel Bradley, a geneticist at Trinity College, Dublin, Ireland.

    The new work “eliminates the possibility that horses were domesticated in one place and spread from there,” says David Anthony, an archaeologist at Hartwick College in Oneonta, New York. Instead, it suggests that today's domestic horse resulted from the interbreeding of many lines of wild horses in multiple places. Even so, Anthony still thinks that horses are likely to have been domesticated first on the steppes, because the archaeological evidence suggests that people there depended heavily on horses for food. Perhaps what spread, he says, was not the horses themselves but the idea and know-how of taming horses.

    Marsha Levine is not convinced. An archaeologist at the McDonnell Institute for Archaeological Research in Cambridge, U.K., she takes issue with both the archaeological evidence cited by Anthony and others and the new mtDNA data. She worries that modern horse DNA won't tell the whole domestication story. But, as Olsen points out, solving the riddle of equine domestication has been so difficult that “anything that helps nail it down is a big help.”

  5. ECOLOGY

    How Rain Pulses Drive Biome Growth

    1. Jocelyn Kaiser

    Most ecologists trying to picture how climate change will remold the world's ecosystems have been fixated on temperature. Piles of studies have predicted that as North America heats up a couple of degrees over the next century, the distributions of everything from oak forests to tundra may shift far to the north. But these ecological modelers haven't factored in the dramatic changes in storm frequency—and the droughts and heavier rains and snows those changes will bring to some regions—also predicted in a greenhouse world. Now, on page 481, researchers describe the first study to look at how swings in precipitation alter landscapes across an entire continent. This new research finds that some ecosystems respond much more strongly than others to pulses in rainfall, which can spur surprisingly dramatic bursts in plant growth.

    Scientists had suspected that fluctuations in rainfall could strongly affect productivity, says ecologist David Schimel of the Max Planck Institute for Biogeochemistry in Jena, Germany. “But it hadn't been confirmed, and it hadn't been quantified at the ecosystem scale.” One of the first papers to synthesize data from a network of ecological sites set up by the National Science Foundation (NSF) 20 years ago, the study highlights the value of long-term data sets for understanding broad ecological patterns, adds Schimel: “It speaks to the importance of having these measurements made in the right place at the right time.”

    The amount of plant growth—or more precisely, productivity—of a patch of land is “the fuel on which ecosystems run,” determining why deserts are so barren and rainforests so lush, notes Alan Knapp, an ecologist at Kansas State University in Manhattan. To explore how tightly precipitation drives productivity in different biomes, Knapp and co-worker Melinda Smith turned to NSF's Long Term Ecological Research (LTER) sites. At the 24 LTERs, researchers routinely track precipitation and what's known as “aboveground net primary production”—recorded by painstakingly measuring the growth of plants each year. Because measurements are taken in a consistent way at the various sites, the LTER network offers an unparalleled storehouse of data for comparing ecosystems, says Knapp. He and Smith drew on data spanning 6 to 23 years from 11 North American sites, including arctic tundra, grasslands and old fields, and eastern forests.

    Some results were expected. Productivity was higher at sites with more average annual rainfall. And forests, with their relatively huge plants, had the highest production from year to year, with grasslands coming in second and deserts third.

    But to their surprise, the duo found a different pattern in how these biomes responded to fluctuations in precipitation. Forests, which receive fairly stable amounts of annual rainfall, grow roughly the same amount in wet or dry years. Deserts, which were hit by the wildest swings in rainfall and thus could be expected to vary enormously in productivity, fluctuated only moderately. Instead, grasslands proved the most extreme, four times more variable than forests—a sizable difference. Grasslands may be so variable, the Kansas team surmises, because of their underlying growth potential: Compared to deserts, grasslands have more leaf area and can grow more densely. And compared to forests, grasslands receive and retain much less water, so they're less buffered against dry years.

    Another unexpected result was that in all of the biomes, wet years had a much greater effect on plant growth than did dry spells. Knapp and Smith think that reflects plant properties that enable them both to resist drought and sprout new growth when well watered. Plant physiologists have noticed this resilience, Knapp says. “The question was, does it scale up to the ecosystem level·” he says. “We've shown that it does.”

    These new data should enable ecologists to improve their models of how biomes may respond to human-induced climate change, as well as to short-term patterns such as El Niño, says ecologist Ian Woodward of the University of Sheffield in the U.K. Knapp sees an additional value: Grasslands may serve as “early warning systems” that ecosystems are being altered by a changing climate—long before the trees migrate northward.

  6. ASTROPHYSICS

    Microwave Telescope Data Ring True

    1. Charles Seife

    Scientists listening for the faint hiss of radiation left over from the big bang have just gotten an earful. Data from a telescope in Chile designed to hear the cosmic background radiation are providing strong support for theories about how the universe evolved during the first few hundred thousand years after the big bang. The result—which shows a signal that other experiments have missed—is the first from the Cosmic Background Imager (CBI) and the beginning of what scientists say could be a banner year for cosmology.

    “It's really an exciting time,” says Scott Dodelson, a cosmologist at Fermi National Accelerator Laboratory in Batavia, Illinois. The CBI is catching the whispers of radiation born about 300,000 years after the big bang, when the universe was too hot for atoms to form. Light was constantly scattered in the monstrous plasma fireball, which reverberated with echoes of the great explosion. But as the universe cooled, electrons settled down with nuclei to form atoms. The opaque plasma became transparent, and the light that had been scattered and rescattered broke free.

    That light, in the form of microwaves, now bombards Earth from all directions, allowing telescopes sensitive to that radiation to take pictures of the 300,000-year-old universe. Most recently, BOOMERANG, a balloon-borne experiment that circled the South Pole, made an exquisite map of the background radiation in a small region of the sky (Science, 28 April 2000, p. 595). But excited astronomers were puzzled when the data failed to show an expected pattern in the distribution of the radiation.

    The early universe, scientists knew, rang like a bell after the big bang. Pressure waves rattled throughout the cosmos, causing variations in density that now show up as ripples in the amount of background radiation. And just as a bell's sound is made up of a fundamental frequency and a number of weaker higher- frequency overtones, the pressure waves in the universe had a “fundamental” of large-size peaks and dips in density and “overtones” of smaller and weaker peaks. BOOMERANG detected the fundamental's first peak but failed to detect the overtone second peak—as if theorists had predicted a bell but heard a horn instead. The missing second peak challenged observations of the amount of matter in the universe and threatened theories about how atomic nuclei formed. “It's a dilemma. The cosmic background is telling us one thing, but nucleosynthesis is telling us another,” says Dodelson.

    Now, to cosmologists' relief, the latest observations suggest that the second peak is there after all. “I think the discrepancy is real,” says Anthony Readhead, an astronomer at the California Institute of Technology in Pasadena who was on the CBI team. “I don't think it is likely to go away.”

    Unlike the balloon experiments, which detect incoming radiation by converting it into heat, the CBI uses interferometry— detecting the phase and amplitude of incoming microwaves directly. Because interferometers have only recently become sensitive enough to measure cosmic background radiation, it's too early to say that the missing signal is definitely there, says Jeffrey Peterson, a cosmologist at Carnegie Mellon University in Pittsburgh. “But it takes a little of the sting out of the worries about the second peak.”

    However, Peterson says that another aspect of CBI's observations is worth celebrating now as support for an important theory about the acoustics of the early universe. The data show a drop-off in ripple size as the angular scale gets smaller and smaller, indicating that the overtones are weaker and weaker. “It's kind of exciting. It's the first time it's been seen in one experiment,” Peterson says. “The acoustic oscillations in the early universe were dying away. It shows we're on the right track, that the acoustic model is right.”

    Readhead and his colleagues will publish their work in Astrophysical Journal Letters. Meanwhile, they are just beginning to analyze the flood of data from CBI. With more BOOMERANG results to come and other cosmic background experiments in sight, astronomers expect that the infant universe will soon snap into sharper-than-ever focus.

  7. SPACE STATION

    U.S. Module to Offer Long-Term Lab Space

    1. Andrew Lawler

    CAPE CANAVERAL, FLORIDADestiny has arrived for U.S. microgravity scientists. After 17 years of planning, dozens of reviews and redesigns, and billions of dollars, the U.S. scientific centerpiece of the international space station is ready to open its hatches for business. Called Destiny, the 8.5-meter-long aluminum vessel is scheduled for launch next month from Kennedy Space Center here. But putting the laboratory module into orbit—a 19 January launch was delayed 3 weeks due to electrical problems—is only the first step in a long and difficult road toward making the space station a scientifically credible venture.

    About 120 researchers have already been chosen to conduct experiments in the lab. But the station's long-term value to U.S. commercial and academic researchers—nearly half the current portfolio is from industry—hinges on the ease of operations in space as well as on NASA's ability to fund, streamline, and provide a clear scientific direction for its troubled life and microgravity sciences effort. “This is going to be our Hubble” Space Telescope, says Kathie Olsen, NASA's chief scientist and acting life and microgravity sciences chief. “We need to get the community involved to do the right type of research.”

    With space station assembly expected to continue until 2006, the lab initially will look more like a construction site than a haven for research. But NASA managers say the module represents a quantum leap in doing science in orbit, with more room, a bigger crew, and far more computer and electrical power than the aging Russian Mir, due for a fiery death in the atmosphere late next month. It's also expected to be open all day, every day, for more than a decade. Once fully outfitted, 13 of the new module's 24 closet-sized racks holding equipment will be devoted to research, and the rest to operational systems. In time, the space station's scientific capacity will be augmented by modules with European and Japanese labs, and the fretwork of metal outside the pressurized labs will provide real estate for astrophysics research. “We now will have more time on orbit, new technology, and a lab built to stay current,” says Roger Crouch, chief scientist for the station. “This is an entirely new paradigm for research in space.”

    Researchers are withholding judgment. “Nobody knows how the station will operate—it's all been on paper for so many years,” says Jay Buckey, a medical researcher at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, who serves on the National Research Council's (NRC's) space biology and medicine panel. “It's a great opportunity to do research, but it's going to be a challenge,” says Peter Voorhees, chief of NRC's committee on microgravity research and a materials scientist at Northwestern University in Evanston, Illinois.

    Each rack provides room for individual experiments. The station's crew already is performing some nominal research, including growing corn and soybean seeds, examining movement of structures in a microgravity environment, and photographing Earth. But the seed work is considered “education and outreach” rather than hard science, and the structures experiment has run into technical problems.

    With crew time and cargo space devoted to construction, “research for now will be very limited,” admits Olsen. And like in any Earth-bound lab, equipment is essential. In March, a Human Research Facility with devices to monitor astronauts will be added, followed a year later by a glove box for performing microgravity experiments, such as combustion research, and a freezer for storing tissue cultures. In the meantime, research will consist of growing crystals and measuring the space environment and its impact on the crew. The station's research future also depends on leadership and money, and both are in doubt. Applications are due by 15 March for the job to head up the life and microgravity sciences office, leaderless since May, and researchers worry that the program is drifting (Science, 12 May 2000, p. 938). Last week, NASA informed principal investigators in the program of a 5% budget cut to accommodate pork projects imposed by Congress. “It's not the best message, but we had to come up with some strategy,” says Olsen, who is advocating a bigger research budget and finding a seasoned and credible chief to put the program on track.

    That credibility won't come easily. Many mainstream biologists and materials scientists remain skeptical of the high cost and low return of space research, noting that last year the NRC criticized NASA's crystallography and biotechnology programs for being too parochial. Voorhees's panel is about to begin a study examining other aspects of space station microgravity science—such as fluid and combustion research—and provide guidance for ground-based efforts, which traditionally have been underfunded.

    Getting the lab off the ground could help boost support for station science, but it's only the start. “It will take a while for people to believe this is real,” says Kathryn Clark, NASA's chief scientist for human exploration. “After all, it's been on the drawing board for so long.”

  8. TAIWAN

    Political Spat Delays Funding for Academy

    1. Dennis Normile

    TOKYOLee Yuan-tseh, the Nobel Prize- winning president of Taiwan's Academia Sinica, is paying a price for his political activism. Opponents of Taiwan President Chen Shui-bian, to whom Lee gave a pivotal endorsement just before last spring's election, have taken out their unhappiness with Lee by withholding legislative approval of Academia Sinica's 2001 budget. The move followed an intense all-day grilling of Lee during what is normally a routine budget hearing and has raised questions about whether partisan politics will hobble Taiwan's premier collection of research institutes.

    Lee, a chemist who returned to Taiwan in 1994 after a long career in the United States, is credited with revitalizing the academy by attracting new talent and launching several research programs (Science, 19 May 2000, p. 1164). So great is his popularity that he was widely touted as a candidate for premier, and his endorsement of Chen, who was locked in a tight three-way race, was front-page news in Taipei. But his latest initiatives are now on hold after the imposition of what amounts to a budget freeze.

    The drama played out through December during the annual budget review. As he has every year since taking the academy post, Lee appeared before the legislature, which is still controlled by an opposition coalition, to explain his request and take questions. This year the legislature was out for blood. “From 9 in the morning until 4:30, all they asked about was his politics,” says Sunney Chan, the academy's vice president for academic affairs. The tension grew when Lee, out of the country for a conference, missed a second budget hearing. Miffed at a perceived snub, the legislature withheld $200 million for the academy from a budget it passed on 4 January pending another appearence by Lee after it reconvenes in late February. But the academy is allowed to continue paying salaries and ongoing expenses.

    Legislators say they are simply trying to be careful stewards of public money. But newspaper editorialists have characterized their decision as foolish retaliation for Lee's support of Chen. Observers expected the impasse to be resolved after Lee's return engagement. “I don't think [the legislators] will really withhold the budget; they just want some respect from Academia Sinica,” says a spokesperson for Taiwan's Government Information Office.

    In the meantime, academy officials have rallied behind Lee and are trying to make the best of things. “We are working and everybody's salary is being paid,” says (Fred) K. Y. Lo, director of the Institute for Astronomy and Astrophysics. Large expenses have been deferred, however, and a dozen or so new research projects are stalled because of an inability to recruit technicians or postdocs. “It's going to mean a 6-month delay in starting these programs,” says James Shen, director of the Institute for Molecular Biology.

    Lo says the real worry is that the skirmish could undermine the “stability and continuity” of support for Academia Sinica and for scientific research in general. “If this goes on every year,” he adds, “it could discourage [top researchers] from coming to Taiwan. I don't think the legislature has considered these consequences.”

  9. SCIENTIFIC COMMUNITY

    Anthropological Warfare

    1. Charles C. Mann

    A book charging anthropologists with mistreating Yanomamo Indians and conducting flawed research has reopened old wounds in the community. It has prompted a fierce firefight, but so far little public soul-searching

    In one of the most remarkable gatherings in the annals of anthropology, almost 1000 researchers, students, and journalists jammed into a hotel meeting room on 17 November for a raucous symposium. The subject: Darkness in El Dorado: How Scientists and Journalists Devastated the Amazon (W. W. Norton), a just-released book by journalist Patrick Tierney. Well before publication, Darkness—a detailed, 400-page indictment of the treatment by anthropologists and the media of the Yanomamo Indians in South America—had become “an enormous problem for the entire discipline,” according to Amazonia specialist Thomas P. Myers of the University of Nebraska, Lincoln. Surprisingly, the symposium, held at the annual meeting of the American Anthropological Association (AAA), included no researchers who specialize in the Yanomamo. AAA representatives, asked about the lack, succinctly explained the problem: The rift within the discipline had grown so bitter that no neutral Yanomamo experts could be found.

    The Yanomamo are a group of 27,000 Native Americans who occupy a Texas-sized chunk of forest around the Orinoco River at the border of Brazil and Venezuela. (They are also known as Yanomami, Yanoama, and Yanomamö—different terms come from different dialects.) Living in 300 scattered, ring-shaped village compounds in the forest, the Yanomamo are among the least westernized peoples on Earth. They have exerted a continuing fascination on anthropologists; more than three dozen have worked with them.

    By far the most well known is Napoleon A. Chagnon, a professor emeritus at the University of California, Santa Barbara (UCSB). Chagnon began his fieldwork in 1964 and quickly became celebrated for his first book, published in 1968, Yanomamö: The Fierce People—” the greatest ethnography ever done,” according to anthropologist Mark Flinn of the University of Missouri, Columbia. Until the 1970s, Chagnon worked with James V. Neel, a prominent geneticist at the University of Michigan, Ann Arbor, and documentary filmmaker Timothy Asch, who eventually made 39 films with him. Both collaborations ended fractiously, in part because Chagnon thought that he was not receiving proper credit. (Asch died in 1994; Neel, early last year.)

    The three men are at the center of Darkness in El Dorado. Many of Tierney's criticisms of them have long been voiced within anthropology itself, for Yanomamo ethnography has been a focus of intellectual and political strife for 25 years. In addition, Chagnon's work has featured prominently in the sociobiology wars, the high-voltage debate over the extent to which human behavior is genetically determined. But Tierney's book, says Kenneth Good, a Yanomamo specialist at New Jersey City University in Jersey City, “brings in so much new material that even those of us who have been on the scene are amazed. … A lot of anthropologists are running scared, and I believe there will be international legal repercussions.” Indeed, on 21 December Venezuela created a blue-ribbon commission to investigate Tierney's allegations.

    Although Darkness faults researchers and institutions from the Atomic Energy Commission to National Geographic, it focuses on three main areas:

    • A 1968 measles epidemic that killed “hundreds, perhaps thousands” of Yanomamo; the book contends that Neel's group, which included Chagnon and Asch, may have exacerbated or unintentionally even caused this epidemic; Tierney also accuses the researchers of conducting unethical genetics studies.

    • Chagnon's characterization of the Yanomamo as “fierce” and violent, and his later claim that Yanomamo who have killed have greater reproductive success; Tierney argues that both are wrong and have led to abuse of the group.

    • The disturbance of the Yanomamo economy by anthropologists, whose massive provision of goods to villagers, in Tierney's account, has upended traditional political balances, debased wealth-seeking villagers, and even led to murderous conflict.

    Tierney has received support from many Yanomamo experts and some other anthropologists, including Marshal Sahlins of the University of Chicago, who wrote in a Washington Post review that Darkness is “a revealing book, with a cautionary message that extends well beyond the field of anthropology.”

    But Chagnon sharply disagrees. “Almost every damn sentence in the book is false,” he said in an interview with Science. “There's absolutely nothing in the book about me, for instance, that's accurate or that isn't distorted in a way that makes normal behavior look foolish.”

    “I can't imagine more serious charges,” says Kim Hill of the University of New Mexico, Albuquerque, who strongly disputes most of them. “But they all point to a serious problem: Anthropology has a huge lack of policy about interacting with uncontacted peoples.” He adds: “If this book focused attention on the enormous suffering, now and in the future, of native peoples [in South America], I could almost forgive Tierney his massive mistakes.”

    A case of measles

    Tierney's most explosive charge is that Neel and his colleagues used a risky measles vaccine, with disastrous results, to inoculate Yanomamo they were studying in an ethically problematic genetic survey.

    The U.S. Atomic Energy Commission funded Neel's genetic studies, which began in Japan after World War II. One of the goals was to establish background levels of spontaneous mutation in the Yanomamo, whom Neel believed to be exposed to fewer environmental mutagens than were people in industrialized societies. From the mid-1960s to the 1970s, Chagnon functioned as a kind of house ethnographer for the study.

    During the Michigan team's first visits to the Yanomamo in 1966 and 1967, “they drew titers [standard test volumes of blood] for measles,” says Neel's son, physician James V. Neel Jr. “They found the Amerindians had virtually no exposure to measles.” In eight of 10 tested villages, the Yanomamo had almost no measles antibodies at all. “My father realized that if in fact wild measles ever got into that population, they were at very high risk of catastrophic consequences,” says his son. “The death rate in a virgin [unexposed] population is 20% to 30%.”

    When Neel, Chagnon, Asch, and three other members of the Michigan team arrived in Yanomamo territory on 22 January 1968 to draw more blood for their genetic studies, they came equipped with 1000 doses of Edmonston B measles vaccine, which Neel had obtained gratis from Lederle and Parke-Davis, according to his papers. By that time, however, Edmonston B was being replaced in Western nations by the newer Schwarz vaccine, which had many fewer side effects. Tierney therefore criticizes Neel's choice of a “primitive,” “dinosaur vaccine” for the Yanomamo.

    Indeed, Edmonston B was not an obvious choice. One of the first measles vaccines, it must be accompanied by a shot of gamma globulin to ameliorate its side effects. In two of three previous studies of measles vaccine in Native Americans, researchers concluded that the risk of severe febrile response was an impediment to the use of Edmonston B. And on 18 January 1968 the Venezuelan government recommended that children in the nation be vaccinated with Schwarz vaccine.

    Neel seems not to have written a protocol for his vaccination program, so his rationale for choosing Edmonston B is unknown, and no records that he obtained permission to vaccinate in Venezuela have been found. (In October the Brazilian newspaper O Globo reported a similar lack in Brazil, where Neel also worked.) But Francis Black, a retired Yale public-health specialist who long worked with Native American vaccination programs, suggests that Neel may have chosen the older vaccine because he could get it for free. “Because of the gamma globulin, [Edmonston B] was generally more expensive and complicated to administer,” Black says. “But we did have 10 years of experience with it, so I felt it was a rational thing to do.” In addition, Neel's suppliers, Lederle and Parke-Davis, did not make Schwarz vaccine, which was not yet widely manufactured in the United States, according to Susan Lindee, a historian at the University of Pennsylvania in Philadelphia who has written extensively about Neel's field research.

    The 10 years of experience did Neel little good during his 1968 trip. Within weeks of his arrival, as Tierney reports, measles exploded around him. In a nightmarish scenario, the disease felled Yanomamo almost simultaneously at a number of widely spread villages. Working in what seems to have been confusion and near-panic, Neel and his team tried to vaccinate ahead of the disease, creating what he called in his memoirs an epidemiological “firebreak.” Meanwhile, they tried to shoehorn in their research, taking thousands of blood samples while Asch shot hours of film.

    “Neel is constantly saying [during this period] that there are things that he wants to do but that he can't do to fulfill his production quotas [of blood samples],” Tierney said in an interview with Science. “You can sense his agony and frustration. … He talks about going to these places and helping them out, but he doesn't do it. What he's actually doing is going off with all these blood samples.”

    At least one vaccinated child subsequently died of measles, Tierney writes. And because measles appeared in the area soon after the team's arrival, he argues that the vaccine itself may have caused the epidemic—or that its side effects, combined with the malaria and viral infections endemic to the Yanomamo, were severe enough to be indistinguishable from deadly wild measles. (Edmonston B's side effects are exacerbated if the recipient has a cold, Black says, and Neel's diary records that he had a “beastly URI” [upper respiratory infection], which he likely passed on.) Asch's audio tapes of the expedition, discovered by Tierney and listened to by Science, suggest that expedition members themselves, bewildered by the way the disease seemed to be springing up everywhere around them, wondered whether the vaccine might be a cause.

    Vaccine experts argue that the vaccine could not have touched off the epidemic. Measles vaccine co-developer Samuel L. Katz of Duke University says Edmonston B, Schwarz, and other live-virus measles vaccines are extremely unlikely to be transmissible. Surprises can always happen—oral polio vaccine apparently caused an outbreak in the Dominican Republic last summer (Science, 8 December 2000, p. 1867)—but both Edmonston B and Schwarz vaccines, Katz says, “have simply never been seen to be transmissible from a vaccine recipient to a susceptible contact.” The vaccine's side effects may have been severe, especially because the Michigan team was unable in most cases to provide care afterward. Nonetheless, Katz says, “many more would have died if Neel had not been there.”

    “If Sam Katz had originally told me this vaccine could never start an epidemic, I don't think I would have pursued this study,” Tierney says. “Instead he was so amazed by Neel's report [of extremely severe side effects] that he asked me to send him the abstract. … [The measles researchers'] initial attitudes were very different than what they say now.”

    Measles may have appeared in the area before the Michigan team arrived, according to evidence that surfaced recently. Documents collected in November by Thomas N. Headland, an anthropologist at the Summer Institute of Linguistics in Dallas, Texas, indicate that the 27-month-old daughter of missionary Keith Wardlaw contracted measles in late August 1967 while being taken to Manaus, Brazil, to treat gum problems. After the Wardlaw family returned to its post on the Toototobi River, about 25 km south of the Venezuelan border, the girl broke out with measles. She became sick, Wardlaw recalled in an e-mail to Headland, just as the local Yanomamo “were having a typical Yanomamo feast” to which “they had invited three neighboring villages”—an estimated 150 to 200 people. “With very few exceptions, everyone of the Yanomamo present at the feast came down with the measles in September or October 1967,” Wardlaw wrote. Seventeen died, mostly of secondary infections, despite the Wardlaws' emergency flight to obtain penicillin. Around 13 January 1968, a subsequent article in the missionary journal Brown Gold reported, the disease erupted in Tamatama, Venezuela, about 300 km north of the Toototobi villages and 120 km upriver from the Ocama mission, where the Michigan team arrived just over a week later.

    As for the taking of blood samples—the main reason for the Michigan team's 1968 visit—Tierney argues that was also problematic. The Yanomamo, he points out, did not give informed consent to the research. At the time, informed consent was a hot issue—a 1966 article in The New England Journal of Medicine listing 22 unethical experiments had provoked nationwide controversy. But standards would not become clearer until the 1971 revelation of the Tuskegee experiment, in which syphilis patients were deliberately left untreated, prompted federal regulations 3 years later. “Clearly, you wouldn't do what Neel did today,” says philosopher Robert P. Crease of the State University of New York, Stony Brook, who conducts mandatory ethics classes for university researchers. “But the standards were not so clear at the time.”

    Fecund killers

    Although the allegations surrounding the measles epidemic have received the most public attention, Tierney's criticisms of Chagnon's ethnographic studies and the conclusions he draws from them have reopened old wounds in the anthropology community. Chagnon's repeated visits to the Yanomamo, beginning with his work with Neel and continuing sporadically into the 1990s, says UCSB anthropologist John Tooby, produced “one of the only detailed, quantitative data sets we have about small, face-to-face societies. It may sound surprising, but it is very rare for anthropologists to keep careful accounts of births, deaths, and family trees for every person in a village.” Chagnon's work is especially important, Harvard biologist Edward O. Wilson has written, because Yanomamo culture may provide “the clearest view of the conditions under which the human mind evolved biologically during deep history.”

    “That's just baloney to me,” says Headland, who put together an AAA session in 1994 about an earlier Chagnon controversy. “The Yanomamo do not give us a view of the way the human mind evolved in deep history. … They are 20th-century human beings who, it is true, live more traditional lives than we do, but they evolved right along with the rest of us. Their mind and their society is not going to give you a glimpse of our ancestors evolving.”

    From his first study of “the fierce people,” Chagnon has depicted the Yanomamo society—a putative model for early human cultures—as dominated by violence. Indeed, he says, about a third of all adult male deaths among the Yanomamo are due to warfare and homicide. Traditionally, most anthropologists have argued that intergroup conflict is caused by competition for scarce resources, especially food. But in a widely publicized article (Science, 26 February 1988, p. 985), Chagnon proposed instead that Yanomamo violence is associated with higher genetic fitness. In this culture, he wrote, men who have killed—unokai, in the language—are rewarded by “higher reproductive success,” because they have “greater success in finding mates.”

    Chagnon's unokai thesis was quickly denounced by other Yanomamo specialists. In charges that Tierney repeats and amplifies, anthropologist Bruce Albert of the University of Paris contended in Current Anthropology that Chagnon's mortality data must come from unrepresentative villages, because his figures for violent death were higher than those from other researchers into Yanomamo society. Albert's colleague Jacques Lizot asserted in American Ethnologist that Chagnon's “systematic bias” led him to gloss over the fact that the category of unokai is not reserved to men who have personally killed human beings. As Tierney does in Darkness, Lizot castigated Chagnon for making it “impossible to determine the precise origin of the quantitative data.”

    Perhaps the sharpest critique came from R. Brian Ferguson of Rutgers University in Newark, who said in American Ethnologist that Chagnon had failed to account for confounding variables. First, many unokai were also village headmen, who have been known for decades to “have more wives and more children, regardless of the presence of war.” Second, Chagnon's figures on reproductive success did not include dead unokai. The obvious question, in Ferguson's view, was whether the greater reproductive success of unokai was offset by higher mortality. Responding in American Ethnologist, Chagnon calculated the same figures without the headmen and came up with a correlation similar to, although smaller than, his previous figure. But, Chagnon told Science, he “didn't record at the time the status of unokai men who were killed,” which is necessary to respond to Ferguson's second objection. “But from what I know,” he says, “it looks as though [Ferguson's] hypothesis doesn't hold up.”

    “The suggestion that Chagnon is somehow off his rocker … to believe that [killing is associated with greater fitness] is totally unwarranted,” says Hill of New Mexico, who works with the Ache foragers in Paraguay. “That said, most of his demography is pretty crude.” Based on his own, similar survey of Ache reproduction, Hill believes that Chagnon may have confounded higher fertility and higher child survivorship. “The same guys who were killers have a lot of other characteristics,” he says. “The most important is that they are healthier and stronger than the other men.” Because “men who are big and healthy and robust produce kids who are healthy and robust, I don't find it surprising that their children have higher survivorship.”

    In Tooby's view, many of these criticisms are stand-ins for a deeper objection: an “antiscientific” objection to the intrusion of biology into anthropology. “There's a very fundamental view, basic to the origin of anthropology and sociology, which is that psychology and biology have nothing to do with human behavior,” he says. Anthropology is in crisis today, in his view, “because there's an overwhelming body of evidence that this is not correct, of which [Chagnon's] work is a major part.”

    Political correctness?

    Tierney, who identifies himself as a human rights activist, is less concerned with Chagnon's scientific role than with his methods and the impact his arguments have had on the Yanomamo themselves. Put briefly, Tierney charges in Darkness in El Dorado that Chagnon and Neel were able to obtain blood samples and detailed genealogical data only by going to extraordinary lengths—lengths that Tierney believes not only had a disproportionate impact on Yanomamo culture but that actually led to war.

    Yanomamo specialist Good says that the Yanomamo dislike providing blood, because they believe it gives the recipient power over them. As a result, Neel's research, Tierney writes, was “a production-line collection of 12,000 biological samples, each of which had to be purchased by Chagnon with a steel good”—usually a machete, ax, or cooking pot. Chagnon also wanted Yanomamo names. But, as he has written, they do not speak names aloud—especially the names of the dead—because names have powerful magical properties, so he gave out machetes and axes for the information. Showing up with piles of steel tools, Chagnon was, as he wrote in The Fierce People, besieged by “incessant, passioned, and aggressive demands” for axes and machetes, to which he often “succumb[ed].” He also explained that he was “‘bribing’ children [to tell names] when adults were not around, or capitalizing on animosities between villages” by getting enemies to inform on each other. “It all adds up to this sudden, destabilizing infusion of wealth,” Tierney said in an interview.

    Metal goods first came to the Yanomamo in the 1930s, but stone tools persisted until the late 1970s, according to Robert Carneiro of the American Museum of Natural History in New York City. In a study by Hill and Hillard Kaplan of the University of New Mexico, Albuquerque, it took up to 60 times longer to cut down trees with stone axes than with steel axes—a ratio that does not include the time needed to find, make, and maintain stone ax heads. So inefficient were traditional tools, Venezuelan anthropologist Marcus Colchester has argued, that before contact, the Yanomamo must have made their living by foraging, rather than agriculture.

    The arrival of the Michigan team with large quantities of steel goods therefore “had a huge effect,” says William Denevan, an archaeologist emeritus at the University of Wisconsin, Madison, who worked in Amazonia for decades. “Chagnon repeatedly says [in his writings] that he wants to keep these people as free of outside influence as possible. And yet from his own writing it's obvious that through his introduction into the economy of these metal tools he's having a major impact himself, which is completely contradictory.”

    Tierney argues that these goods changed the balance of power among villages. He writes, for example, that a village in which Lizot lived became politically powerful in part because of goods that Lizot bestowed. He alleges that Lizot, a respected researcher who lived among the Yanomamo for 25 years, used gifts to lure young Yanomamo males into satisfying his sexual appetites. (In an interview with Time, Lizot called the charges “disgusting. … My house is not a brothel. I gave gifts because it is part of the Yanomami culture.”) Incredibly, Tierney writes, “Lizot's village” made war on “Chagnon's village”—a settlement that became strong because Chagnon had resided there in the past. (He was not in Venezuela at the time of the war.) Ten people died; Lizot's village was burned to the ground.

    “The way entire villages formed around anthropologists and evolved a lifestyle around them is one of the most chilling things I discovered,” says Tierney, who spent 15 months in Yanomamo territory. The power acquired by “Chagnon's village” led to constant warfare and death that ceased as soon as he left the field, according to Darkness. Little wonder, Tierney says, “I kept hearing people say how much they hated the anthropologists who had studied them.”

    “People have accused me of being the greatest violator of the Heisenberg Uncertainty Principle in the history of anthropology,” Chagnon says. “But they don't mention that the missionaries [in the area] were having a far greater impact than I ever could have.” Ferguson agrees that missionaries should share the blame. But because Chagnon, in his quest for large-scale genealogical information, “had to go back and forth between villages and had so many goods to give out, he became a participant in the politics and a source of tension,” Ferguson says.

    The already heated dispute among anthropologists acquired an additional charge in the late 1980s, when the Yanomamo area was invaded by thousands of gold miners, some of whom cited Chagnon's views as evidence that the Indians were too murderous to deserve protection. Introduced disease killed many Yanomamo; a single massacre left 16 Indians dead. A 1991 congress in Caracas on the Yanomamo was, according to Chagnon, “frequently punctuated with ad hominem denunciations of me.” As the battle raged, Chagnon was prevented from visiting Yanomamo territory for years at a time.

    One of the few aspects on which all sides agree is that the Yanomamo—along with other relatively unacculturated groups—are in peril of extinction. At the San Francisco meeting, the AAA and its members were charged with failing to come up with ground rules for managing contact with such cultures. “This Tierney business is dreadful for anthropology,” says Leslie Sponsel, an anthropologist at the University of Hawaii, Manoa. “But it could force the governments of Brazil and Venezuela to pay more attention to the Yanomamo, and the AAA to professional ethics. I keep thinking there's got to be something good to come out of this. A lotus flower grows out of the muck in a pond, after all.”

  10. SCIENTIFIC COMMUNITY

    Preemptive Strike Sought to Discredit Book Before It Was Published

    1. Charles C. Mann

    For anthropologists, it was the e-mail heard ‘round the world.

    At the end of August, anthropologists Terence Turner of Cornell University and Leslie Sponsel of the University of Hawaii, Manoa, e-mailed the president of the American Anthropological Association (AAA) with a startling announcement about an “impending scandal” that would rock the discipline. A forthcoming book, Darkness in El Dorado by journalist Patrick Tierney, was charging several prominent researchers with mistreating the Yanomamo Indians in Venezuela—and worse. In “scale, ramifications, and sheer criminality and corruption,” Turner and Sponsel wrote, the revelations in Darkness were “unparalleled in the history of Anthropology,” and they urged that the charges be investigated. Within 2 weeks the e-mail had spread from AAA headquarters to what seemed to be the e-mail box of every anthropologist in the United States. “For a while there I was receiving it two or three times a day,” says William Irons, an anthropologist at Northwestern University in Evanston, Illinois. “It was incredible—I must have got several dozen copies.”

    Irons had reason to be concerned. Tierney's chief target was a longtime friend, Napoleon A. Chagnon of the University of California, Santa Barbara (UCSB). Chagnon is celebrated for his ethnographic studies of the Yanomamo, which began in 1964. But he contributed to another discipline, known variously as evolutionary psychology, Darwinian anthropology, or sociobiology. And it was this group of researchers—along with colleagues of the late James V. Neel, a renowned University of Michigan, Ann Arbor, geneticist also attacked by Tierney—that has most forcefully challenged Darkness in El Dorado.

    Leading the charge was John Tooby, a Chagnon colleague at UCSB who is president of the Human Behavior and Evolution Society (HBES). Known for his fierce advocacy of evolutionary psychology, Tooby quickly concluded that Darkness in El Dorado was “full of lies” and decided to blunt its “potentially dangerous” impact. “I couldn't sit by and let this book go unchallenged,” he says.

    Working almost full-time, Tooby, Irons, and other Chagnon friends, and the Michigan researchers assembled an anti- Darkness campaign so swift and forceful that it produced lengthy rebuttals of Tierney's work before he had published a single word. Like the original, vitriolic e-mail from Turner and Sponsel, the counterattack was based on early galleys of the book, some key details of which were changed in the published version. Many who joined the debate hadn't even seen the galleys, and Tierney—at the insistence of his publisher, W. W. Norton—declined to comment before publication. But if nothing else, the vehement anti- and pro-Darkness efforts illustrate how, for better or worse, the tactics of modern political campaigns, complete with opposition research, “war rooms,” and over-the-top rhetoric, are infiltrating scientific research.

    “Lives are at stake.”

    Chagnon is no stranger to controversy. His belief that Yanomamo culture is dominated by waiteri (ferocity) has long been a subject of dispute (see main text). But Tierney's detailed indictment was “something completely different,” he says. “I've always had my critics, and some of them got kind of personal, but this kind of thorough attack is unheard of—he goes after my ‘beer belly,' my dogs, and even the fact that I was raised in a small town in Michigan, which supposedly makes me a McCarthyite.” Chagnon promises to respond in The Noble Savage, a book to appear next summer.

    Tooby, for his part, did not want to wait that long. He thought the Turner-Sponsel warning was “scientifically illiterate,” according to a manuscript he posted on his Web site. (A version was later published in the online magazine Slate.) Tooby wrote that he worried that people could misuse Tierney's claims to stop immunization programs in underdeveloped nations: “People, especially in poorer countries, would die as a result.” After alerting the Centers for Disease Control and Prevention about the imminent publication of what he depicted as an antivaccination book that could kill “certainly in the thousands, possibly in the millions,” Tooby urged CDC scientists “to get in touch with the journalists who I knew were working on the story.”

    Knowing that the Turner-Sponsel note was landing in reporters' laps, Tooby also spent “the next several days” in “a frenzy of calling, faxing, and e-mailing” the media. He put the case starkly to reporters. “Lives are at stake,” he wrote. “Once a reputable first-world source such as [the journalist's organization] puts its prestige behind such a claim (even if it is hedged), no subsequent retraction will ever catch up with it or undo the damage.”

    Others went to work, too. With the support of Neel's family, the University of Michigan assembled what Michigan archaeologist Kent V. Flannery called “a fact-finding committee” of “physicians, epidemiologists, geneticists, biological anthropologists, ethnologists, ethnohistorians, archaeologists, documentary film specialists, and eyewitnesses to James Neel's and Napoleon Chagnon's fieldwork … working together to figure out why such hideous allegations would be made about them in the media.” They were supported by Neel's genetics colleagues, including L. Luca Cavalli-Sforza of Stanford University, who predicted in an e-mail to Science that Tierney's “pretentious and largely defamatory contribution” would soon be discredited.

    At UCSB, Tooby, anthropology instructor Edward Hagen, and graduate student Michael Price set up what Hagen jokingly called a “war room”—“it's just filled with paper, and we've practically been living in it.” By barraging journalists with e-mail, the researchers managed to hold off some press coverage; Tooby thought that he had helped kill a story at The Washington Post. “I couldn't believe the pressure they put on me,” says a science journalist at another paper. “They were saying, ‘Even if you just truthfully report what people are saying, it will be misused and people will die because of what you wrote.' I felt like saying, ‘Where was this concern when you were telling me that it wasn't Chagnon's fault if the gold miners or whatever misused his words?'”

    Despite the pressure, the Chronicle of Higher Education, which had previously covered disputes over Chagnon, ran a story on 20 September. The AAA was forced to issue a statement promising a full investigation. From that point on, media coverage was intense. “Scientist killed Amazon indians to test race theory,” blared the headline in the Guardian of London on 23 September. Darkness in El Dorado was featured in Newsweek, U.S. News, The New York Times, USA Today, the BBC, and South American newspapers.

    Meanwhile, Neel biographer and historian Susan Lindee of the University of Pennsylvania in Philadelphia was reexamining Neel's field notes, writing on 21 September that the true events “were at some variance” with the version in the Turner-Sponsel e-mail. (Subsequently she retracted her statement that the notes proved “Neel had Venezuelan governmental permission to carry out the vaccine program.”) Six days later, the University of Michigan “fact-finding team” issued a full refutation of the charges against Neel. Although he admitted he had not seen the galleys of Tierney's still-unpublished book, Michigan medical-school dean Allen Lichter told reporters that “we have complete confidence that [Neel's] actions were above reproach.”

    By 9 October, UCSB's Price had unofficially posted a long, harsh critique on a university Web site of Tierney's “numerous examples of error and deception.” That same day The New Yorker published an excerpt of the book—the first chance for readers to see anything by Tierney himself. Darkness in El Dorado was nominated for the National Book Award 2 days later.

    Political science

    Meanwhile, Chagnon, faced with the upcoming publication of the book, lined up famous names in his defense, including Harvard biologist Edward O. Wilson, who wrote the foreword to the most recent revision of Chagnon's major Yanomamo book; evolutionist Richard Dawkins of Oxford University, author of The Selfish Gene; Massachusetts Institute of Technology cognitive scientist Steven Pinker; Tufts University philosopher Daniel C. Dennett; Harvard neuropsychologist Marc Hauser; and British science journalist Matt Ridley. Chagnon says he also began consulting libel lawyers “very seriously.”

    “It is clear to me that academics from all disciplines are going to make a stand on this …,” Chagnon wrote to supporters on 27 September. “It is not simply an attack on me, Jim Neel, and a few others, it is an attack on the integrity of all responsible scholars.”

    Arguing that releasing Darkness “after so much evidence has come to light showing Tierney's accusation to be false is … unethical,” Northwestern's Irons sent the 700 members of HBES on 4 November a proposal for boycotting W. W. Norton, Tierney's publisher. (Irons is the incoming president of HBES.) Unexpectedly, Bruce Alberts, president of the National Academy of Sciences (NAS), leapt into the fray, issuing on 9 November a highly unusual statement deploring the “misleading or demonstrably false” statements in Darkness in El Dorado. Like other elements in the anti-Tierney campaign and the Turner-Sponsel e-mail, the statement attacked some claims that Tierney didn't actually make. For example, Alberts criticized Tierney for writing that Neel had “selected this vaccine mindful of its harmful results … in order to record the response of the Yanomami to this ‘virulent' virus vaccine in hopes of confirming eugenic theories that Neel purportedly espoused.” But this charge—and the description of the vaccine as virulent—were not in the published book.

    One day after Alberts released the NAS statement, Tooby and his UCSB colleagues posted a 60-page rebuttal of Tierney's book on their pro-Chagnon Web site (www.anth.ucsb.edu/chagnon.html). Their statement made the extraordinary claim that “The major allegations [in Tierney's book] appear to be deliberately fraudulent.” Three days after that, the University of Michigan released an expanded version of its statement. By 16 November—Darkness in El Dorado's official publication date and the day before an AAA panel on the book at the association's annual meeting in San Francisco—lengthy counterarguments were available from half a dozen sources. In turn, Tierney's responses were available at www.darknessineldorado.com. And the press began weighing in with reviews, many of them favorable (“will become a classic of anthropological literature”—The New York Times).

    The AAA open-mike session on 17 November was a confusing barrage of speakers, with pro- and anti-Tierney voices trading accusations of “racism” and “political correctness” in a welter of rapid citations. UCSB researchers handed out anti-Tierney flyers and copies of their “preliminary report.” The Brazilian Anthropological Association noted that it had complained to AAA about the “harmful effects” of Chagnon's research 11 years before. “As far as we know, nothing was done then,” the Brazilians said. The AAA, for its part, announced that a special ad hoc task force would “examine assertions and allegations contained in Darkness in El Dorado” and decide by February “which specific issues, if any, are deserving of an in-depth investigation.”

    “The whole business was very odd,” says William Denevan, an archaeologist emeritus at the University of Wisconsin, Madison, who has worked extensively in Amazonia. “There's a lot of defensiveness on the part of the whole discipline of anthropology without really having the facts or details.” He adds, “Very few of the people who spoke had actually done any research on the Yanomamo, yet they almost all had extremely strong opinions. And 95% of the audience hadn't read the book, but there they were clapping and cheering one side or the other.”

  11. AMERICAN GEOPHYSICAL UNION

    Geophysicists Probe the Solar System's Cold Spots

    1. Richard A. Kerr

    SAN FRANCISCO, CALIFORNIA—Last month, the American Geophysical Union held its annual fall meeting here as a nip in the air strained the state's power grid. Temperatures, especially low ones, were prominent in several of the offerings: ice in martian mid-latitudes, coordinated climate change on Earth, and ozone problems in the chilly stratosphere.

    Girding Mars With Icy Dust

    The mid-latitudes of Mars have long looked odd to earthly observers. In the late 1970s, the Viking spacecraft imaged ground there that seemed to have “softened” like ice cream on a warm day into a rounded, much subdued terrain. Now, closer inspection has revealed a wealth of textural detail in mid- latitudes that planetary scientists are comparing to the surface of a basketball. The martian mid-latitudes, it seems, harbor ice whose gradual removal leaves much of the planet wildly textured. If so, the two mid-latitude zones may harbor the lingering remnants of Mars's last ice age a million years or so ago, rather than the possibly life- sustaining liquid water suggested by last summer's discovery of springlike seeps on Mars.

    As described at the meeting, the “stippled terrains” came to light as planetary geologists John Mustard, Christopher Cooper, and Moses Rifkin of Brown University in Providence, Rhode Island, laboriously inspected more than 8000 high-resolution images produced since 1999 by the Mars Global Surveyor spacecraft. They found that a peculiar stippled terrain covers a sizable portion of the ground between 30° and 60° in each hemisphere of Mars. It consists of expanses of smooth, featureless terrain interrupted by steep-walled pits a few meters across. The pitted ground grades into a knobby or stippled terrain that grades in turn into a roughened terrain. “We've noticed this [texture] as well,” says planetary geologist Michael Carr of the U.S. Geological Survey (USGS) in Menlo Park, California. “It's very real.”

    On closer inspection.

    Stippling seen at higher resolution hints at an ice-rich martian surface.

    CREDITS: NASA/JPL/MALIN SPACE SCIENCE SYSTEMS

    Mustard and his colleagues have also put together a plausible scenario for how the stippled terrain might have been generated. They suggest that about a million years ago, when the changing tilt of Mars's rotation axis last favored an even colder climate than today's, windblown dust accumulating in the mid- latitudes could have become welded into smooth-surfaced icy rock as water condensed and froze between dust grains. “This is the last glacial event on Mars,” said Mustard. Then, once the axial tilt swung back to favor a somewhat less chilly climate, the finely divided ice holding the soil particles together began sublimating away to the poles. As a result, the smooth ice layer, originally 1 to 3 meters thick, began to disintegrate slowly, producing an increasingly textured surface. Carr supports this idea and adds that the draping of such a dust layer across an initially rougher terrain could have contributed to the rounding and softening of the surface noted in fuzzier images from the Viking orbiters that flew in the late 1970s.

    Other planetary scientists seeing the new images also think the Brown group is onto something. “I know what they're talking about,” says James Zimbelman of the National Air and Space Museum in Washington, D.C. Their interpretation “is certainly believable. I think ice is involved.” Still, he adds, “I don't believe ice explains everything.” Wind erosion may play a role too, he says.

    Whereas the extensive ice age remnants proposed by the Brown group could explain the odd look of a fair portion of the surface of Mars, they could pose a problem for astrobiologists hoping to find life on the planet. Mustard and his colleagues noted that the distribution of the stippled terrain closely coincides with that of the “weeping layers” of rock reported last summer. At the time, some researchers proposed that the water that flowed at the surface had always been liquid, having flowed up from deeper, warmer rock. Such continuously liquid water is requisite for life.

    But the Brown workers estimate that if those weeping layers contain as much water in the form of ice as stippled terrain seems to, simply melting the ice of the first few meters of rock would have been sufficient to produce the observed flows and debris fans. “It's all consistent with a lot of water ice in the near-surface,” says planetary geologist Ken E. Herkenhoff of the USGS in Flagstaff, Arizona. And because it's unlikely that perennially frozen surface layers could support living organisms, those seeking signs of life may have to look elsewhere.

    Getting Climate In Sync

    It's natural enough in this age of telecommunications to view the world as tightly interconnected. Until now, however, researchers have always regarded major regional climate fluctuations as independent of one another. The warm-cool cycle of El Niños and La Niñas in the tropical Pacific seemed not to affect the great monsoon that so many in southeast Asia depend on; the shifting weather patterns of the North Atlantic that alternately warm and chill Europe seemed unconnected to the fluctuations in and over the North Pacific that drive everything from salmon populations to big surf in southern California. But now that view may be changing. At the meeting, a group of climate researchers reported finding decades-long intervals when two or more of these “climate modes” seem to dance in step. How they interconnect and why they sometimes fall out of sync remain mysteries, but the finding bodes well for long-term climate prediction.

    Teasing out interconnections among these climate modes required a nontraditional approach to climate analysis. Climate researcher Tim P. Barnett of the Scripps Institution of Oceanography in La Jolla, California, and his colleagues borrowed a statistical analysis technique from signal processing in electrical engineering. Unlike conventional climatological methods, the technique can identify when two modes are in step with each other, even if they fall out of step from time to time. Barnett and his colleagues compared 118-year-long records of indices gauging the states of two modes at a time. (The synchronization technique can't yet handle three or more.) To test how much synchronization chance alone might produce, they ran 1000 tests analyzing records that they themselves had constructed to have no real synchronization. Only if the actual observations were more synchronized than these simulated records could mode synchronization be considered real.

    Somewhat to their surprise, Barnett and his colleagues found that climate modes are not as independent-minded as had been assumed. “I think there's definitely something there,” says Barnett. The tests of synchronization “turn out to be highly significant statistically. About half the time one pair of modes or another is in synchrony with each other. The other half of the time they're off doing their own thing.” Barnett is calling the synchronization of any two or more modes the “hypermode,” a term coined by co- author Niklas Schneider.

    For 2 or 3 decades at a time, the Southeast Asian monsoon, for example, waxed and waned in strength in step with El Niño, only to go its own way later, as it has during the past decade. “There seem to be some tantalizing hints that there are at least times when these modes are acting in concert,” says climate modeler Benjamin Santer of Lawrence Livermore National Laboratory in California. Adds modeler Jeffrey Kiehl of the National Center for Atmospheric Research in Boulder, Colorado: “Tim showed that communities of scientists that focus on their favorite mode of climate variability may have to talk to one another. That's unique.”

    How individual climate modes communicate to create the hypermode or are forced into it remains unclear. The 20- to 30-year pacing of shifts in and out of the hypermode suggests to Barnett that some part of the ocean is calling the tune, because only the ponderous changes of ocean circulation could pace such slow changes in the climate system. The atmosphere, however, under the direction of the ocean, could provide connections between modes in much the way El Niño can reach out through the atmosphere to affect weather as far away as North America. Identifying such mechanisms of pacing and interconnection will take a lot of climate modeling, says Barnett; even a 118-year record is too short for that.

    An Ozone Milestone

    The battle to save the ozone layer has reached a major goal: halting the decades-long rise in the burden of ozone-destroying chemicals in the stratosphere. International controls on the production of chlorine-containing compounds such as chlorofluorocarbon (CFC) refrigerants have slowed and finally stopped the increase, atmospheric chemists reported at the meeting. If all goes according to plan, the antarctic ozone hole could heal by the middle of this century. But researchers are quick to caution that uncertainties remain, particularly in the future course of ozone-destroying bromine in the atmosphere. And as stratospheric temperature and water content change, they threaten to enhance the destructive power of existing chlorine and bromine.

    A stratospheric balancing act.

    Although the powerful ozone-destroyer bromine is still increasing (yellow), decreases in chlorine have caused the overall ozone-destroying potential (ECCl, dashed blue) to plateau.

    CREDIT: J. W. ELKINS/NOAA

    Atmospheric chemists have been monitoring the stratosphere's buildup of the full suite of ozone-destroying substances for a decade. At the meeting, Dale Hurst of the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, speaking for his colleague James Elkins (who was stuck in Antarctica by bad weather), reported that the combined ozone- destroying capacity of chlorine and bromine in the lower stratosphere—where most ozone loss occurs—leveled off around 1999.

    The prime driver behind the stratospheric plateauing was the precipitous decline—as mandated by the 1987 Montreal Protocol—in the production of methyl chloroform. Production of the industrial cleaning agent ceased in 1994, supplies were rapidly depleted, and its stores in the atmosphere are quickly being eroded by natural destruction. Methyl chloroform's decline was so sharp that it compensated for the continued increase in stratospheric bromine from fire-extinguishing chemicals called halons, whose abundance in the atmosphere is still increasing at rates of 2% to 5% per year.

    So far, NOAA data—gathered from gas chromatographs on NASA's high-flying planes and balloons, and ground measurements—suggest all is proceeding according to the protocol plan. But “the future is somewhat uncertain,” warns Elkins. Soon the decline in chlorine from methyl chloroform will cease to be a factor, but mandated reductions in CFCs and in halons manufactured in developing countries will begin to kick in, assuming the protocol is followed. But, in fact, emissions of halons have been running 50% above the amounts expected, according to calculations by Stephen Montzka of NOAA, Boulder, suggesting that the production figures from such countries as China are off, that more halons stored in fire-extinguishing systems around the world are being released than assumed, or both.

    Another sort of threat to the recovery of stratospheric ozone arises from a matter of accounting. Researchers have long recognized that, molecule for molecule, bromine is far more destructive of ozone than chlorine is. The usual assumption in calculating ozone- destroying potential is that bromine is 45 times more potent than chlorine in destroying ozone molecules. That's the assumption underlying the NOAA calculation that the stratosphere's burden of ozone-destroying chemicals has plateaued. But “it's pretty clear that 45 is the low end of the range,” says atmospheric chemist James Anderson of Harvard University. An analysis by Anderson and his Harvard colleagues suggests a better factor “is closer to 60 to 80 times,” he says. If so, the ongoing rise in stratospheric bromine would still be driving up ozone destruction. Anderson hopes that researchers can settle on a single bromine factor this year.

    Beyond accounting uncertainties loom nonhalogen atmospheric changes. Increasing greenhouse gases in the stratosphere are radiating more heat to space and cooling the stratosphere. At the same time, stratospheric water vapor is increasing, for unknown reasons. Each of these changes tends to encourage the formation of the icy cloud particles that accelerate springtime ozone destruction over polar regions (Science, 10 April 1998, p. 202). “Over the next few decades,” says Anderson, “changes in stratospheric temperature and water vapor could overwhelm reductions” in chlorine and bromine.

    To follow how stratospheric ozone is coping with all its stresses, keep your eye on the Arctic, says Anderson. Each spring the mix of chemicals, water vapor, and temperature has been depleting ozone until a full-fledged ozone hole, approaching the one that forms each year over the Antarctic, now threatens to emerge. The Arctic is “sitting right on this cusp,” Anderson says. The next decade or so should tell.

  12. ECOLOGY

    Arctic Life, on Thin Ice

    1. Kevin Krajick*
    1. Kevin Krajick is a writer in New York City.

    Field observations from the Beaufort Sea to Hudson Bay suggest that many species are floundering in a warming environment

    Ivory gulls are disappearing—or so say Inuit hunters living on the northernmost fringes of Canada. No one is sure that the hunters' claim is true; ivory gulls lead mysterious lives, cloistered in remote aeries far from prying eyes. Besides, scientists are loath to rely on anecdote. But biologist Grant Gilchrist of the Canadian Wildlife Service (CWS) takes the observation seriously. The Inuit, he notes, “live on ice,” like the gulls that forage the frozen Arctic all the way to the North Pole. And he believes in statistics, too: Arctic ice cover is melting, transforming the ivory gull's habitat.

    Sea ice in the Arctic now covers 15% less area than it did in 1978; it has thinned to an average of 1.8 meters, compared to 3.1 meters in the 1950s (Science, 3 December 1999, p. 1828). If this trend continues, in 50 years the sea ice could disappear entirely during summers—possibly wiping out ice algae and most other organisms farther up the food chain, including polar bears. Whether or not that Arctic nightmare comes true, temperature fluctuations and winds driving the melting are already making many cold-weather creatures uncomfortably warm. And melting is bringing a new threat: people and their machines. In 1999, Russian companies sent two huge dry docks to the Bahamas through the usually unnavigable Northwest Passage, which winds through the labyrinthine Canadian Arctic Archipelago above the North American mainland. The route is also being eyed by oil companies drilling off northern Alaska.

    Even when compared to the Antarctic, the Arctic Ocean was long thought a biological desert: hemmed in by land, it is choked with ice nearly year-round. But studies have found that it can be a rich, dynamic habitat. The ice partially breaks up during the brief summer, forming a moving jigsaw puzzle of floes driven by wind. This creates openings for life: Amid the intricate topography, diatoms and invertebrates dwell within the ice or in narrow open-water leads between floes. Algae such as Melosira arctica form slime jungles on the ice's fleecy underbelly, and clouds of zooplankton below graze on the algae or each other. In the 1970s, Igor Melnikov, a biologist with Moscow's P. P. Shirshov Institute of Oceanology, studied the Beaufort Sea in the Arctic Ocean's lower reaches and found 200 species in various niches—up to 140,000 individuals per cubic meter in the ice.

    Now with the ice thinning, there is evidence that this food web is ailing. In winter 1997–98, Melnikov returned to his original study area during the international climate-change project SHEBA (“Surface Heat Budget of the Arctic Ocean”). Melnikov found everything changed. The diatoms were gone, replaced by a few common freshwater algae. Melnikov says the algae may have taken over because melting has formed a 30-meter-thick layer of relatively fresh water below the remaining ice, a third deeper than it was 20 years ago. Ice-related invertebrates had largely disappeared, including the most abundant —his own Theristus melnikovi. “It is a type of catastrophe,” he says. His findings, in press at Deep Sea Research, were not a one-season phenomenon: He duplicated them last summer aboard a Russian icebreaker.

    There is no evidence of such shifts farther north—yet. However, says Rolf Gradinger of the Institute of Polar Ecology at Christian-Albrechts University in Kiel, Germany, who studies sea ice closer to the pole, “these are big changes, and we are worried about the food web if they spread.”

    Because smaller ice creatures are food for larger ones, experts fear a domino effect. For one, tiny carcasses rain down on the Arctic sea floor, nourishing bottom dwellers such as clams—the main prey of walruses. Ubiquitous arctic cod operate like upside-down vacuum cleaners on the ice's undersurface, sweeping up whatever they can get with their upturned mouths. Cod are the primary prey of many kinds of seabirds, whales, and seals. At the top of the food chain are the polar bears, dining mainly on seals.

    Besides fraying the food web, the ice pack's shrinkage threatens the livelihoods of the big animals, which hunt, rest, and reproduce on the pack. Some melting and fracturing is necessary for seabirds to dive for fish, for most seals to haul themselves out, and for whales to surface for air. But extensive melting puts prey out of reach for some species. At the height of summer, the ice breaks up along the pack's southern fringes, triggering a burst of plankton productivity along the edges. The breakup also exposes countless cod, schooled so thickly they turn the water black. Ed Carmack, an oceanographer with the Canadian Department of Fisheries and Oceans, has witnessed thousands of harp seals, whales, and birds attracted to such areas for feeding frenzies. Whales and seals have no problem chasing the movable feast as the ice edge recedes earlier in summer and farther northward. But seabirds tied to cliffside nest colonies can forage only as far north as there is suitable land.

    The plight of one bird species shows just how fine the balance between ice and open water must be for survival. At first, receding ice was good for black guillemots off Alaska's northern coast. Before the 1970s, summer cold and snow prevented them from nesting on Cooper Island, in the Beaufort Sea near Point Barrow, Alaska, says George Divoky of the University of Alaska, Fairbanks. As the seasonal ice edge pushed north, the birds settled and flourished, with numbers peaking at 450 in 1989; but in the last decade, the population has dwindled to 250. “The ice edge outran them,” says Divoky. “Now it's way out in the Chuckchi-Beaufort Sea, where there is no land.”

    Some 3500 kilometers southeast of Barrow, along northern Hudson Bay, thick-billed murres are adapting to the receding ice edge by eating open-water fish such as capelin, says CWS ornithologist Tony Gaston. But capelin are less nutritious than cod, and Gaston has documented a decline in murre weight. The birds are also suffering a devilish twist: Populations of mosquitoes, never before a big problem in this area, have exploded in the higher temperatures. Bitten repeatedly on their big webbed feet, many murres, unable to flee while incubating eggs, keel over dead in their nests. “It's probably a combination of heat exhaustion and getting sucked dry by bugs,” says Gaston, who will add fresh details to this tale in an article later this year in the journal Ibis.

    No one is quite sure how the elusive ivory gulls, which dwell farther north, are faring. Some major colonies were discovered only in the 1980s on remote nunataks, mountaintops poking from vast glacial ice fields on high-arctic Ellesmere Island. These aeries may protect the birds and their young from bears and foxes unwilling to cross the barren inland glacial ice. Thus, if the glacial ice begins melting in concert with the sea ice, the birds could face a double whammy: loss of food and increased predation. Gilchrist hopes to find funding to study the nunatak aeries this summer.

    Ringed seals, the most common northern seals, may have trouble adapting too, says Brendan Kelly of the University of Alaska's School of Fisheries and Ocean Sciences in Juneau. Ranging year-round as far as the pole, they never leave the ice pack, keeping breathing holes open all winter and making lairs under snow mounds. In spring, the snow lairs camouflage their new pups from polar bears and protect them from cold air. But in the current issue of the journal Arctic, biologist Lois Harwood of the Canadian Department of Fisheries and Oceans says the ice in the western Arctic broke up 3 weeks earlier than usual in 1998, and hungry pups were dropped into the water before weaning. Adults appeared thin, even though early breakup led to more available prey. “They were starving in the midst of plenty,” says Harwood.

    Kelly fears that the seals may already be in danger farther north even without visible ice melt. Monitoring of seals fitted with radio collars suggests that pups emerge from the protective snow lairs each spring precisely when warming saturates the snow with water, causing the mounds to collapse. Kelly believes that the earliest time at which pups can survive in open air is finely tuned to this saturation date. If this date is indeed shifting earlier, he says, “things may go very badly for them.”

    Things are already going badly for Peary caribou, but it's unclear why. The animals graze on high-arctic-island plants and lichens, but need ice to island-hop. One population normally migrates from Victoria Island to mainland Canada in the fall, but some are falling through the increasingly unstable ice. “If you fly over, you sometimes see a caribou trail heading across, then a little wormhole at the end, with a bunch of antlers sticking out,” says Anne Gunn, a wildlife biologist for the government of Canada's Northwest Territories. On some islands, other populations have virtually disappeared, although it is uncertain whether the problem is too little ice, too many Inuit hunters or—as a side effect of changing weather—unusual freezing rains that ice over forage, making it inaccessible for grazing.

    Even the mighty polar bears are suffering. In higher latitudes they spend almost all year hunting seals on the ice, although in lower ranges such as Hudson Bay, they retreat to land in summer, when waters open up. With warmer springs in the last 30 years, western Hudson Bay's waters have begun opening weeks early, forcing the bears to make for land around mid- July—a crucial time when they normally gorge on seal pups and store fat for the year. In a 1999 paper in Arctic, CWS biologist Ian Stirling recounts how early landfalls have caused the region's polar bears to suffer 15% declines in both average weight and number of cubs born between 1981 and 1998. While awaiting freeze-up, the bears have taken to hanging around the bayside town of Churchill, with its enticing garbage dump and hordes of bear- loving tourists. Predictably, wildlife officials have had to shoot some problem animals. Churchill now has a 23-cell “bear jail” for troublemakers—bigger than its people jail. Bears are held there until there's enough ice to airlift them out onto the bay.

    Not all change is bad. “Further north, wildlife may be increasing,” as solid ice opens up, says Stirling. Harp seals are being spotted in places where they hadn't been seen before, for example.

    Although no one can say what the various observations mean for the ecosystem's long-term health, some answers may lie on the horizon. Starting in 2002, the National Science Foundation and the Office of Naval Research will fund a $17.5 million program to investigate the biology of climate change in the western Arctic. And the topic is getting a serious airing in the scientific community, including in symposia later this month at the Fingerprints for Climate Change conference in Ascona, Switzerland. “The ‘meltdown' of the Arctic could be exaggerated, like the death of Mark Twain,” says Carmack. “But that doesn't mean we should ignore it. We don't know how animals might adapt, or not. That's why we should be so concerned.”

  13. PACIFICHEM 2000

    Pacific Chemists Throw Switches, Strike at Disease

    1. Robert F. Service

    HONOLULU, HAWAII—Once every 5 years, chemists from North America, Japan, New Zealand, and Australia come together for the International Chemical Congress of Pacific Basin Societies. At last month's meeting, over 10,000 researchers discussed topics that included a new molecular electronic switch and new hope for fighting diabetes and Alzheimer's disease.

    Organic Molecular Switch

    In the drive to create ever-smaller computer chip components, making devices with molecules that switch on and off like transistors is all the rage. So far, such devices have had problems: Either they've required freezing temperatures to operate, or they haven't passed enough electrical current to be useful. But now a team has come up with new molecule-based switches that work at room temperature while passing large currents. The new molecules are already giving the nascent field of molecular computing a lift. “I think this is pioneering stuff,” says chemist Peter Stang of the University of Utah in Salt Lake City.

    In recent months, researchers have demonstrated several types of molecular switches. One team at the University of California, Los Angeles, used a set of molecules called catenanes, made from pairs of intertwined molecular rings. By changing electrical voltages applied to electrodes sandwiching the catenanes, the team showed that they could alter the number of electrons on the rings. This caused the rings to rotate around one another, which altered the ability of current to flow through the catenanes from one electrode to the other. But in constructing the devices, the researchers had to layer the rings atop hydrocarbon molecules. This setup placed the rings closer to one electrode than the other and made it difficult for charges to move through the mix.

    Electrifying.

    When ring-shaped compounds slide down their stems, lollipop-like pseudorotaxane molecules become much more conductive.

    ILLUSTRATION: J. MOGLIA

    To improve the design, the same team, led by chemist Fraser Stoddart and postdoc Julie Perkins, constructed a new class of switching molecules. Called pseudorotaxanes, they are shaped like molecular lollipops. Like the catenanes, the pseudorotaxanes are sandwiched between a pair of electrodes. Positively charged ring-shaped compounds nestle close to an electron- donating portion of the lollipop stem. When an electrical potential is applied between the electrodes, it yanks electrons off the stem area and spurs the ring-shaped compounds to jump to another spot. This jump lowers the electrical resistance of the molecular switch and allows current to flow more easily between the surrounding electrodes, the researchers reported.

    In addition, the physical structure of the new switch design fosters current flow. Like the catenanes, the pseudorotaxanes still need hydrocarbons to help them assemble properly between the electrodes. But, in this case, the lollipops and hydrocarbons sit side by side, allowing the lollipops to be centered between the two electrodes and prompting nearly 100 times more current to flow between the electrodes.

    Stang notes that the pseudorotaxanes aren't ready to compete with Pentium chips just yet, as they tend to break down after a week or so of use. Stoddart says he believes that may be due in part to the fact that the rings can slide off the ends of the lollipops. His team is already at work on new versions of the molecules with bulky groups on both ends to prevent the rings from sliding off.

    A Key to Diabetes?

    Geneticists have been toiling for years to identify the genes involved in adult-onset diabetes, in which cells fail to absorb glucose from the blood. The condition arises either because cells become unresponsive to insulin, the hormone that tells them to take up and store glucose, or because specialized sensor cells in the pancreas fail to detect glucose that should trigger the release of insulin. At the Honolulu meeting, Harvard University chemists reported the first evidence that both problems may stem from a single molecular source, a protein that appears to be the key to sensing nutrient levels in cells.

    The Harvard team—led by chemical biologist Stuart Schreiber—described a combination of new and old work that showed how a small molecule called rapamycin that blocks this protein can both make cells unresponsive to insulin and affect their ability to properly sense glucose and other nutrients. So far, the team has studied nutrient sensing only in yeast, a model organism for understanding how cells sense nutrients. Still, the new evidence “is really quite remarkable,” says Gerry Crabtree, a cell-signaling expert at Stanford University.

    If the studies with rapamycin, an immunosuppressive drug given to organ transplant patients, show that it also affects nutrient sensing in human β islet cells of the pancreas, it could point to a common cause for both pathways to the disease. Crabtree, for one, believes there's a good chance that will happen, because yeast and humans have similar nutrient-sensing genes and proteins. “I think it has a reasonable chance of working out,” he says.

    If so, it could pave the way for new therapies to stop a condition that affects millions of people worldwide. Adult-onset diabetes commonly afflicts people who are overweight and sedentary. Left unchecked it can damage the heart, kidneys, nerves, blood vessels, and lead to blindness. In trying to understand the disease, researchers have traditionally focused on cells' progressive insensitivity to insulin. But the numerous genes fingered as possible culprits account for only about 10% of the cases.

    The Harvard team—which included graduate students Alykhan Shamji and Finny Kuruvilla—didn't set out to find the other 90%. Rather, they decided to study the role of a protein dubbed FRAP that their laboratory had discovered years earlier. Schreiber and his colleagues knew that FRAP—and its twin found in yeast, called Tor—are signaling proteins involved in sensing and response to cellular stress. They also knew that rapamycin blocks FRAP and Tor. The chemists wanted to see what effect blocking these proteins has on the expression of other genes in the cell. To find out, they turned to the increasingly popular gene-chip technology, in this case a version designed to study yeast. The chips contain DNA snippets from all 6200 genes in yeast and are designed to reveal the activity of each gene, whether dormant or in hyperdrive. By comparing gene activity profiles of untreated cells with those of cells given rapamycin, the Harvard team teased out the effect of the drug on yeast's genetic machinery.

    “There was a big surprise,” says Schreiber. In response to rapamycin, yeast cells ramp up the production of genes involved in respiration and the production of the chemical fuel ATP, among other things. “Clearly these cells are trying to generate energy,” says Schreiber. The surprising aspect was that these cells were sitting in a nutrient bath rich with glucose, their primary energy source. But they weren't using it. Instead, the yeast cells were turning on genes to process ethanol—their backup energy source—as well as proline and urea, backup sources of nitrogen. Indeed, the researchers found that their gene expression patterns looked just like those of yeast cells deprived of their primary nutrients.

    “These [rapamycin-treated] cells are swimming in a sea of glucose. Yet they think they are starving,” Schreiber says. From this he concludes that the drug has indeed blocked the cells' nutrient sensor, Tor.

    That condition, Schreiber notes, is reminiscent of diabetes, in which cells bathed in insulin no longer respond to its message to absorb glucose. In fact, human patients who take rapamycin as an immunosuppressant commonly develop a diabetic-like condition as a side effect of the drug. Moreover, Schreiber says, previous work has shown that when cells that are normally responsive to insulin are given rapamycin, they become insulin resistant.

    The group is currently looking at the response of pancreatic islet cells to rapamycin. If the drug also appears to trick these cells into thinking they are in a starvation environment, it would suggest that FRAP—Tor's mammalian counterpart—is indeed the master switch regulating cells' response to nutrients. For now that remains a big if. But if it pans out, it could give diabetes researchers new hope for finding a molecular keystone at the center of the disease.

    Alzheimer's Suspect

    For researchers working to stop Alzheimer's disease, the chief molecular suspect has long been clear: a protein fragment called β amyloid that builds up in the brains of Alzheimer's sufferers. This presumably leads to the brain neuron loss underlying the disease, but pinning down just how β amyloid damages nerve cells has been hard. Some researchers suspect that at least part of its neurotoxicity is due to its promoting the creation of free radicals, reactive chemicals that can kill cells by tearing apart their proteins and fatty membranes. Just how β amyloid might foster free radical production has remained a mystery. But at the Pacifichem meeting, Kentucky researchers reported results linking free radical generation to a particular amino acid in β amyloid, and also showed that antioxidants such as vitamin E counter the damage.

    The new evidence “is important,” says William Klunk, who directs the Alzheimer's research program at the University of Pittsburgh Medical School in Pennsylvania. It lends heft to the notion that free radical damage could kill neurons around the β amyloid deposits in the brain. Other processes may also promote damage, Klunk stresses. But if the free radical mechanism holds up, it suggests that antioxidants targeted to cross easily into the brain and bind to β amyloid could help stave off damage from the disease. “That's an interesting hypothesis and a testable one,” says Zaven Khachaturian, an Alzheimer's expert and consultant in Potomac, Maryland.

    The notion that free radicals generated by β amyloid may play a role in Alzheimer's gained initial support in 1994 when Allan Butterfield and his colleagues at the University of Kentucky, Lexington, reported that the peptide produces free radicals in the test tube. Later, they and other researchers showed that reactions involving the peptide could form free radicals capable of setting off a chain of damaging reactions between lipid molecules in cell membranes.

    That still didn't pinpoint what it was in β amyloid that set the ball rolling in the first place. But Butterfield, a chemist, had a guess when he took a look at the peptide's amino acid sequence. Most of the 42 amino acids that make up β amyloid are fairly unreactive. But number 35, methionine, is a compound known as a thioether, a good free radical generator. To test whether methionine is indeed the culprit, Butterfield and his colleagues synthesized both normal β amyloid and a version that swapped a synthetic amino acid called norleucine for the methionine at position 35. Norleucine differs from methionine by a single atom, a carbon in place of a sulfur. When the researchers added the two versions of β amyloid to separate cultures of rat neurons, they found that the normal version of the peptide generated free radicals and killed the neurons, while the modified version had no such effect. When they then added vitamin E to the culture with the normal β amyloid, the antioxidant prevented free radical formation and cell death.

    But that wasn't all. Butterfield's team went on to test their modified β amyloid in a living organism, the worm Caenorhabditis elegans. In this experiment, the researchers replaced methionine with cysteine, a natural amino acid. In collaboration with Christopher Link of the University of Colorado, Boulder, they genetically modified worms so that they made either normal human β amyloid or the cysteine-containing version. They found that the worms making the normal β amyloid generated free radicals that damaged their muscle proteins. Those making the cysteine version, however, had no damage and produced the same amounts of free radicals as did controls that received an empty gene-delivery vehicle.

    Taken together, Butterfield says, the new results suggest that β amyloid's methionine amino acid is the primary culprit for generating free radicals that can go on to kill nerve cells. If this free radical damage winds up being the chief cause of the disease, it suggests that antioxidants may stem the tide. Early trials with high doses of vitamin E in humans have proven only moderately successful. But Butterfield notes that vitamin E isn't very efficient at crossing the blood-brain barrier and doesn't preferentially seek out sites with β amyloid. In hopes of doing better, drug companies are now working feverishly to develop novel antioxidants that cross into the brain easily and home in on β amyloid.

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