News this Week

Science  06 Sep 2002:
Vol. 297, Issue 5587, pp. 1622

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    Physical Sciences Need Boost, Advisory Panel Tells Bush

    1. David Malakoff

    Researchers in the physical sciences sorely need a significant budget boost to close a ballooning gap with biomedical research, a high-profile White House advisory panel said last week. But in a bow to budgetary realpolitik, the President's Council of Advisors on Science and Technology (PCAST) is vague about specific spending targets and timetables.

    The recommendation will be contained in a letter to be delivered shortly to President George W. Bush, just as the White House begins crafting its 2004 spending proposal to Congress. The move reflects growing pressure on the Administration and Congress to reverse a decade-long slowdown in federal funding for basic and applied research in physics, chemistry, math, and other nonbiomedical disciplines, which totaled about $9 billion last year. That stagnation, advocates say, has imperiled the nation's ability to develop new talent and technologies and to fully cash in on the taxpayers' $25 billion investment in biomedical science.

    “It's great: PCAST is [endorsing] what a lot of people have said needs to happen,” says David Peyton, a technology specialist with the National Association of Manufacturers in Washington, D.C., and vice chair of the Alliance for Science and Technology Research in America. The nonprofit alliance is one of many that have called for doubling the budgets of the National Science Foundation and other agencies that fund the physical sciences.

    Unbridgeable gap?

    Funds for physical sciences (mostly chemistry, physics, and astronomy) have remained flat while life sciences have soared. A panel chaired by G. Wayne Clough (bottom) is calling for “parity.”


    But while some industry and congressional leaders have embraced the idea, the White House has remained quietly skeptical. Last week, presidential science adviser John Marburger again challenged physical science advocates to back their case with solid numbers. The president “bristles at arbitrary formulas,” he told PCAST members during a hastily called teleconference to fine-tune the letter, drafted by a PCAST subcommittee led by G. Wayne Clough, president of the Georgia Institute of Technology in Atlanta. Marburger suggested deleting the word “doubling” from the draft letter, saying it had become “politically charged” and “unpalatable.” He also urged panel members to take the long view, noting that it recently took 5 years to double the budget of the National Institutes of Health. Swayed by such arguments, the panel is expected to recommend that physical sciences' funding reach “parity” with the life sciences by 2009.

    The definition of “parity” will be up to the reader, says Clough. “It doesn't make sense to say that the physical sciences should get whatever the life sciences are getting,” he told Science. “But the idea is that significant makeup [for the physical sciences] is due here.”

    The letter's two other recommendations are more direct but no more specific on the fiscal implications. One calls for a major new program to fund graduate school fellowships for U.S. citizens, on the theory that greater support might attract more students into the sciences. The other urges the government to do a better job of analyzing what it gets for its money, how the United States compares with other countries, and the future demand for scientists and engineers.

    The effect of the letter won't be visible until February, when the president releases his 2004 budget request. But Clough is optimistic. Budget chief Mitch Daniels, he says, “has proven to be a person that understands good advice.” And even if the Bush budget proposal doesn't include a healthy boost for the physical sciences, science lobbyists will surely point to PCAST's high-level endorsement when they take their case to Congress.


    Survey Confirms Coral Reefs Are in Peril

    1. Elizabeth Pennisi

    A new census of key coral reef inhabitants shows that they are in terrible shape. Spiny lobsters and bumphead parrotfish have disappeared from most of the surveyed reefs they were known to inhabit, as have Nassau groupers, a favorite food fish in the Caribbean. Even moray eels seem to be suffering.

    The tallies come from Reef Check, a 5-year survey of the world's coral reefs by scientists and some 5000 volunteer scuba divers and local fishers. The resulting report, “The Global Coral Reef Crisis: Trends and Solutions,” released last week, describes the decline of both fish and invertebrates essential to the well-being of reef communities. The final word: Reefs “are in dire straits,” says Steve Gittings, a marine biologist at the National Oceanic and Atmospheric Administration (NOAA) in Silver Spring, Maryland.

    The conclusion comes as no surprise. For more than a decade, marine biologists have been complaining about the state of the world's reefs, citing ever more frequent observations of dead or dying coral. Some of the first warning bells sounded in 1990, when it appeared that global warming was killing the microscopic algae that feed corals. Over the ensuing years, researchers also traced the blame to coastal development, overfishing, and pollution.

    Drying up.

    A count of coral reef organisms such as the Nassau grouper (top) and a cowry snail called the flamingo tongue (bottom) revealed human-inflicted losses.


    These conclusions were somewhat shaky, however, because so few reefs had been evaluated; even fewer had been monitored long term (Science, 25 July 1997, p. 491). Stepping forward, Gregor Hodgson, a marine ecologist at the University of California, Los Angeles (UCLA), and his colleagues established Reef Check (Science, 6 June 1997, p. 1494). About 200 people helped with the first survey, in Kauai, Hawaii. By the year's end, the organizers had data on about 300 reefs in 31 countries. That success prompted the establishment of yearly Reef Checks.

    Some researchers have questioned the value of data gathered by volunteers. But according to UCLA's Jennifer Liebeler, a co-author of the report, straightforward protocols and data review by scientists make the results sound. At each site, volunteers and their scientist-supervisors estimate the ratio of live coral to dead coral. Some species they count, such as parrotfish, are indicative of reef quality. Others, such as spiny lobsters, help reveal the extent of overfishing. And a few, such as the giant clam, show how curio and aquarium-trade collectors are affecting reefs. As far as Gittings is concerned, with just a few species to keep an eye on, “the volunteer counts are not going to be that far off.”

    Clive Wilkinson of the Australian Institute of Marine Science in Townsville, Queensland, says that the surveys have given him new information, even though he is a longtime veteran of coral biology. For example, the extent of overfishing was news to him. Sea cucumbers are missing from half the reefs, and in Guam their numbers dropped from 17 per 100 square meters in 1997 to about three in 2001. The Nassau grouper has virtually disappeared: Among 162 reefs, 142 reefs had none, 12 more had just one. But the good news is that marine sanctuaries, where fishing is limited, appear to be working. The surveys found higher numbers of certain key species there compared to other areas, which “is valuable to note,” says Wilkinson.

    Those arguing for new measures to protect reefs may soon get more ammunition. A NOAA report coming out next month highlighting reefs in the United States and U.S. Territories will include data from volunteer surveys, long-term research projects, and remote sensing. And by November, Wilkinson expects to finish a catalog of damage done to reefs, including an assessment of reefs' prospects. Both reports are expected to show widespread damage to reef communities. Gittings hopes the efforts will “continue the momentum” and draw attention to the plight of this marine resource.


    A Brighter Outlook for Good Ozone

    1. Richard A. Kerr

    Things are looking up in the stratosphere. The latest quadrennial assessment of the state of the protective stratospheric ozone layer is just out, and the international report* from about 250 scientists finds that restraints on production of ozone-destroying chemicals such as chlorofluorocarbons are having the intended effect. The concentration of the prime offender, chlorine, is at or near a peak in the stratosphere. And an improved scientific understanding of stratospheric ozone is reassuring scientists that the world has probably seen the worst of ozone loss. Global ozone should soon begin increasing, fast enough that within the decade the infamous Antarctic ozone hole should start to shrink. All this assumes, of course, that signatories to the 1987 Montreal Protocol limiting emissions of ozone-damaging chemicals continue to meet their obligations and that the major remaining scientific uncertainty in ozone's future—climate change—doesn't spring a big surprise.

    When the previous scientific assessment came out in 1998, prospects for stratospheric ozone were muddled. The great eruption of Mount Pinatubo in 1991 had spewed megatons of debris into the stratosphere, where it interacted with pollutant chlorine to accelerate ozone loss. As a result, global ozone plunged to a new low, complicating extrapolations of the rapid ozone losses seen in the 1980s. Most predictions called for ozone losses to worsen in the 1990s, particularly in the midlatitudes, where most people live. The Antarctic ozone hole had been deepening and widening at a frightening rate. And the first model to simulate how accumulating greenhouse gases affect ozone showed future Arctic losses ballooning, even as real Arctic ozone suffered a series of unprecedentedly bad years.

    After four more years of observations and research, stratospheric ozone's future is looking clearer and brighter. The Antarctic hole is obviously hitting bottom over the South Pole each October. During the austral spring, as sunlight returns to the stratosphere, icy polar stratospheric clouds (PSCs) combine with chlorine to catalyze ozone destruction in the layer between 12 and 20 kilometers where PSCs can form. For the past decade, there's been no ozone left to destroy in that layer. But because the thickness of the layer has not increased during that time, the hole's depth hasn't, either. And its breadth—the width of the hole—has increased only slightly since the mid-1990s. “That's positive news,” says atmospheric physicist and assessment chapter co-author Paul Newman of NASA's Goddard Space Flight Center in Greenbelt, Maryland. With ozone-destroying halocarbons expected to be on the decline, Newman says, “by 2010, we could see 5 to 6 years when the hole looks consistently smaller than during the past 5 years.”

    Down but not out.

    Northern midlatitude ozone declined in the 1980s and took a hit from the 1991 Mount Pinatubo eruption but held its own in the 1990s.


    Encouraging news is coming from the Arctic, as well. That scary string of low-ozone years in the mid-1990s (researchers never rated them “holes”) ended with 1997. Four of the 5 years since have seen minimal springtime ozone losses. The Arctic, it turns out, was not plunging into a full-blown, Antarctic-like ozone hole. New modeling reported in the assessment suggests that it might never do so. An early model study had suggested that the greenhouse gases that cool the stratosphere would encourage PSC formation and cause a massive ozone loss (Science, 10 April 1998, p. 202). “It's really looking like the more detailed models don't give that [low-ozone] result,” says atmospheric chemist Susan Solomon of the National Oceanic and Atmospheric Administration in Boulder, Colorado.

    Outside the polar regions, ozone has fared better than feared too. In the 1990s, rather than worsening over the northern midlatitudes, ozone depletion all but ground to a halt. Researchers aren't sure what caused the slowdown. Plateauing halocarbons certainly played a major role, but some researchers have suggested that changes in atmospheric circulation have been a key factor as well (Science, 22 June 2001, p. 2241). If natural variations, global warming, or even ozone depletion itself increased the amount of air moving into midlatitudes from the ozone-rich tropics, for example, midlatitude ozone would be bolstered.

    There is increased evidence that atmospheric dynamics has in fact contributed to the leveling off of midlatitude ozone depletion, says dynamical meteorologist and chapter co-author William Randel of the National Center for Atmospheric Research in Boulder: “Some fraction of ozone changes—probably less than 50%—may be associated with changes in the dynamics of the stratosphere.” No one can say what proportion of dynamically induced ozone change might be natural and how much is human induced.

    A certain amount of optimism runs through the assessment, but so does a note of caution. The effect of climate change remains uncertain, not just on the Arctic but the whole stratosphere. The assessment also notes that although damaging ultraviolet radiation has increased on the order of 10% in some regions, ozone depletion has not been the only cause. Difficult-to-predict changes in cloud cover and pollutant hazes have altered and will continue to alter the amount of ultraviolet reaching the ground, it says. And then there's the human element. Further reductions in the production of ozone-destroying halocarbons are required in the next few years under the Montreal Protocol, especially by developing countries. Without continued reductions, the assessment concludes, ozone recovery could be delayed decades or even indefinitely.


    Rescue Planned for Seed Banks

    1. Erik Stokstad

    Plant germ plasm is a political hot potato. The issue of access to—and payments for—samples stored in gene banks was a sticking point for a treaty signed last fall by 116 nations (Science, 26 October 2001, p. 772). Now it could haunt a new proposal, announced last week, aimed at preserving a deteriorating global network of gene banks.

    On 29 August, a new organization called the Global Conservation Trust used the United Nations (U.N.) World Summit on Sustainable Development in Johannesburg, South Africa, to announce a drive to raise a $260 million endowment to rejuvenate these seed banks. A report also released at the summit shows that shrinking budgets and smaller staffs are hindering repositories' ability to keep seeds available to breeders for improving strains or fighting diseases.

    Crop gene banks around the world hold perhaps 2 million varieties of plants. Some of these, such as wheat, can be stored for years as seed. Others must be maintained in tissue culture. But even seeds need occasional replanting to ensure a viable supply, a laborious and costly process called regeneration. A 1996 survey of 151 countries by the U.N. Food and Agriculture Organization (FAO) found that many facilities were rapidly deteriorating and had a large backlog of samples needing regeneration. A follow-up survey in 2000, analyzed by Chris Higgins and colleagues at Imperial College London, U.K., concludes that “the situation has gotten worse,” says Geoffrey Hawtin, director of the International Plant Genetic Resources Institute in Rome, Italy.


    Many gene banks lack resources to care for rare crop varieties.


    For Enrique Suárez, director of the National University of Agricultural Technology's main gene bank, in Castelar, Argentina, that means insufficient staff to regenerate samples. And the recent devaluation of the peso has left him too poor to buy specialized sample bags to refrigerate some 30,000 samples awaiting curation. “The work at the gene bank is stopped,” he says. “It's very frustrating.” Plant samples are stacking up in two-thirds of the countries surveyed, and the budgets of a quarter of gene banks have been trimmed.

    The Global Conservation Trust teams FAO with the Consultative Group on International Agricultural Research, which runs 11 major gene banks. At the summit, the Swiss government ponied up $10 million, but trust officials say they need 10 times that figure before they will solicit proposals.

    Uncertainty about the governance of the trust could spell trouble, warns Pat Mooney of the ETC Group in Winnepeg, Canada, which defends the rights of farmers in developing countries. Some governments might misconstrue the endowment as a way for industrialized countries to gain control over germ plasm resources, he cautions. “What worries me a lot is that it will open a wide vista for agribusinesses to serve their own purposes,” says Melaku Worede, an agricultural consultant based in Addis Ababa, Ethiopia. But the trust's Ruth Raymond says that developing countries will have a voice in the trust's governance structure, and that several countries are interested in contributing.


    Elaborate Carnivorous Plants Prove to Be Kin

    1. Elizabeth Pennisi

    The Venus flytrap has a muddled family history. Charles Darwin thought this elegant bug eater from the southern United States had close ties to a European aquatic weed called the waterwheel. A century later, researchers decided that the waterwheel's closest kin was not the Venus flytrap but the terrestrial sundew, which also dines on insects. Now a DNA analysis of these botanical carnivores suggests that Darwin's hunch was right after all.

    In many ways, this revised family history makes sense, comments Mark Chase, a plant systematist at the Kew Royal Botanical Gardens in Surrey, U.K.—even though he once suggested otherwise. Of all the plants that feast on animals, waterwheels and Venus flytraps “have taken carnivory to the extreme,” he notes: Each has leaves reshaped into traps that snap shut. Now that their close relationship is “nailed down, it sets the stage for people to ask more intelligent questions about how these mechanisms evolved,” Chase points out.

    Carnivorous plants have come up with a variety of ways to snare their prey: pools of water for drowning unlucky visitors, sticky surfaces that work like flypaper, or “snap traps” that clamp down on morsels in milliseconds. Sundews are flypaper predators; waterwheels and Venus flytraps depend on snap traps. All use their prey not as a food source but to provide minerals.

    Evolutionary biologists have long speculated about how these features evolved. In the late 1800s, Darwin picked up on similarities in the stamens and pistils—a flower's reproductive parts—of waterwheels and the Venus flytrap and suggested that these two plants were closest kin. However, in the early 1990s, Chase and his colleagues threw a fly in the ointment, so to speak, when they compared the DNA of about a dozen carnivorous plants and took a closer look at their morphology. They had no DNA from waterwheels and so relied solely on morphology (Science, 11 September 1992, p. 1491).

    Family ties.

    DNA studies reveal a close relationship between the Venus flytrap (top) and the waterwheel (bottom).


    The 20th century study led researchers to conclude that they should lump the sundew in with the waterwheel and push the Venus flytrap out of the tight-knit group. This family tree had evolutionary implications, says Richard Jobson, a plant systematist at Cornell University in Ithaca, New York. Snap traps might have evolved twice, once in the waterwheel and once in the Venus flytrap. Alternatively, the alignment could mean that a snap-trapping ancestor gave rise to sundews, in which case the less elaborate flypaper traps represented simple, modified snap traps.

    Now a 21st century DNA analysis tells a different evolutionary story. Jobson, Kenneth Wurdack, a plant systematist at the Laboratories of Analytical Biology of the Smithsonian Institution in Suitland, Maryland, and Kenneth Cameron of the New York Botanical Garden have compared four genes instead of the one studied in the 1990s. They conclude that even though the Venus flytrap is terrestrial and the waterwheel aquatic, the world's only two snap-trapping plants are nonetheless siblings. The sundew is no closer than a cousin, sharing a common ancestor much earlier in time, the group reports in the September issue of the American Journal of Botany.

    Cameron and his colleagues contend that this evolutionary arrangement suggests that snap traps evolved only once. Moreover, “our results demonstrate that snap traps evolved from flypaper-trapping plants,” he says. They also think that among snap- trappers, the Venus flytrap came first.

    Chase thinks the snap-trap story might be more complicated than it now looks. The two species “don't live in the same parts of the world,” he explains, and although fossils show that the waterwheel was once common throughout Eurasia, the Venus flytrap is known to grow only in North and South Carolina. That leaves open the question of where the snap-trap plants got started and how they spread.


    How Immune System Gangs Up on Joints

    1. Mary Beckman*
    1. Mary Beckman is a writer in southeast Idaho.

    Mast cells are best known for releasing the dastardly allergy compound histamine, which induces sniffles and swollen eyes. Now rheumatologists have found the troublemaker cells embroiled in another dysfunctional immune system activity: inflammatory arthritis. On page 1689, David Lee of Harvard Medical School in Boston and colleagues report that mast cells in mice act as a bridge linking arthritis's self-attacking antibodies and the inflammation that swells joints.

    It took time to accumulate evidence on the suspects. “There are 20 years of literature documenting mast cells in human inflammatory arthritis,” says Lee. Although mast cells riddle arthritic tissue, no one knew how they contribute to the disease, in part because the cells are difficult to study in humans. So the team took advantage of two strains of mice, one prone to inflammatory arthritis and another lacking mast cells. The mice are “a very nice model to elegantly show the involvement of mast cells. Previously, it was guilt by association,” says rheumatologist Maripat Corr of the University of California, San Diego.

    In rheumatoid arthritis, the two prongs of the immune system cooperate. One, known as innate immunity, immediately pounces on pathogens with cells that devour germs and inflame tissues. The other, called adaptive immunity, forges antibodies to fight invaders it has encountered. Going astray in arthritis, they destroy the synovium, a cushion wedged between bones in joints. Researchers think the disease begins when antibodies are somehow generated against a protein in the synovium. These so-called autoantibodies orchestrate the collapse of the joint lining by drawing in inflammatory immune processes. The inflamed cushion swells and eventually hardens to make joints distinctively gnarled. Until now, no one had determined how the autoantibodies muster up inflammation.

    Lee's team examined whether mast cells spur the interaction between antibody-based and innate immunity. The researchers suspected the cells in part because they have receptors for both autoantibodies and inflammation-inducing proteins known as complement. What's more, mast cells can release inflammatory molecules called cytokines.

    To test this idea, the team turned to so-called K/BxN mice, which have a genetic mutation that causes them to spontaneously develop inflammatory arthritis. Serum taken from these animals and injected into mice of almost any other strain will cause the receiving mouse's paws to swell. The researchers injected K/BxN serum into mice that lack mast cells as well as littermates with normal immunity. As expected, the normal mice acquired full-blown arthritis within 10 days of injection. However, mice without mast cells never manifested the disease. The team also transplanted mast cells into the mastless mice; if then injected with K/BxN serum, their paws flared with inflammation. When the researchers examined arthritic tissue, they saw that the mast cells had spewed their cytokines and other inflammatory chemicals within 2 hours of serum injection.

    The researchers suggest that mast cells residing in synovial tissue are a cellular link between the free-floating autoantibodies and inflammation. Autoantibodies and complement bind to mast cells, the team proposes, which prompts them to dump their cytokines and other inflammatory chemicals, thus calling in the inflammation brigade. Rheumatologist Cornelia Weyand of the Mayo Clinic in Rochester, Minnesota, says the “beautiful study” clearly shows that “mast cells are the key effector cells in translating adaptive immunity to inflammatory disease. When you read the paper, it leaves you very satisfied.”

    How the study translates to human disease isn't as clear, however. Rheumatologist Joseph Craft of Yale University says that mast cell involvement will be hard to verify, because such experiments can't be done in humans. However, the mouse result might explain data showing that a cytokine named TNF-α that is released from mast cells “serves as such a dominant force” in human disease. The most recent therapy developed for rheumatoid arthritis targets this cytokine. The rheumatologists agree that the paper will cause a surge of interest in mast cells—as if the ornery rabble-rousers don't get enough attention from the allergists.


    Japan's Ministries No Longer Call the Shots

    1. Dennis Normile

    TOKYO—When Japan's ministries last week unveiled their budget requests for the fiscal year beginning next April, they revealed eye-popping increases in science-related spending. The Ministry of Education, Culture, Sports, Science, and Technology wants to boost its budget for research in four economically strategic fields by 36%; the Ministry of Economy, Trade, and Industry wants 44% more money for the same areas.

    In past years, the ministries could be confident that they would end up with close to what they asked for. Not this year. The prime minister's cabinet office will now cut and shape the ministries' requests, putting its own stamp firmly on the priorities by deciding which projects actually get increases while holding overall science spending flat. Researchers fear this will further tilt the scales toward economically strategic areas. “I am strongly protesting the fact that funding will be available only when a project will produce immediate results,” says Norio Kaifu, director-general of the National Astronomical Observatory in Tokyo.

    The new procedure represents a significant change in the way Japan crafts its research budget. In the past, when ministries submitted funding requests at the end of August, they expected the numbers to be shaved a little by the time the budget was finalized in December, but the overall science spending trend and the fate of particular programs would be set. In early August, however, the Council on Economic and Fiscal Policy, which is chaired by Prime Minister Junichiro Koizumi, centralized the priority setting.

    Sink or swim?

    Funding for completing the derrick for this ocean drill ship could be among the initiatives swept away by Japan's efforts to trim government spending.


    The council invited bureaucrats making proposals for a certain category of science spending—which provides most of the money for actual research but doesn't cover salaries or facility construction—to ask for up to 20% more than they are getting this year. “The requests will be squeezed [by the council] so science-related spending will be about the same as in the current year,” says an Education Ministry official. An official on the staff of the Council for Science and Technology Policy, which is also part of the prime minister's office, explains that the administration wants “more flexibility in dramatically redistributing budget resources,” something that was difficult when each ministry decided where money would go.

    The budget requests already tilt heavily toward four fields the cabinet deems economically important: life sciences, information technology, the environment and energy, and nanotechnology and materials science. The Education Ministry's requested 36% increase, to $2.6 billion, for the priority fields compares to a proposed 13% increase, to $1.6 billion, for grants to individual researchers and a rise of only 2%, to $370 million, for operating large facilities such as accelerators. Kaifu argues that this rapid shift in priorities not only short-changes basic research but wastes money by pumping up funding in the priority areas faster than labs can increase staffing and facilities to absorb it.

    Just how wide the disparities between fields will become, and even whether science spending is headed up or down, won't be clear until the budget is finalized around the end of the year.


    Embryo Development at the Click of a Mouse

    1. Jon Cohen

    After a 5-year gestation, the Visible Embryo is close to term. A Web site with hundreds of thousands of images capturing in mind-boggling detail the earliest stages of human development, the Visible Embryo is expected to debut later this month. “It's incredibly cool to look at how an embryo develops,” says medical illustrator Elizabeth Lockett, who oversees the project for the U.S. National Museum of Health and Medicine (NMHM).

    The Visible Embryo is based on the 115-year-old Carnegie Embryological Collection, a remarkable set of 7000 human embryos now housed at the national museum, a branch of the Armed Forces Institute of Pathology at the Walter Reed Army Medical Center in Washington, D.C. Initially, the project will post multiple high-resolution digital images of slices of 25 normal embryos at various stages of development. These are a subset of 700 embryos that researchers at the Carnegie Institution of Washington had carefully sliced into serial sections, all of which will eventually be included in the Visible Embryo. In all, the database will take about 9 terabytes of space at the San Diego Supercomputer Center, making it one of the largest medical image resources in the world.

    Digital embryo.

    Colored photograph by Alexander Tsiaris of 7-week-old embryo in collection at the National Museum of Health and Medicine.


    An array of collaborators joined forces to make the Visible Embryo much more than a trove of pretty pictures. Coordinated by George Mason University in Fairfax, Virginia, the project will have educational tools, developed by a team at the University of Illinois, Chicago, that will include animation of organ systems as they develop. Researchers at Johns Hopkins University in Baltimore, Maryland, are designing ways for clinicians in separate locations to discuss and manipulate images that apply to specific cases. Technicians performing ultrasounds on pregnant women, for example, will be able to compare stored images of normal embryos with those in utero. Oregon Health & Science University in Portland has the task of modeling and annotating images of the heart. The whole enterprise, which has cost about $3 million so far, was funded by the National Library of Medicine (NLM) as part of its Next Generation Internet Initiative. NLM also backed the Visible Human Project, a database that posted digital cross sections of a complete male in 1994 and a female the following year.

    Until now, researchers interested in using NMHM's collection had to travel to Washington; they came from all over the world, often staying for several weeks. “It's an absolute treasure,” says Shirley A. Bayer, a professor emeritus at Indiana University-Purdue University Indianapolis who, with her husband Joseph Altman, used the collection for their extensive publications about the development of the brain. Making the images more accessible by putting them online will have tremendous benefits, Bayer predicts.

    Two years ago, Lutz Breitsprecher, a maxillofacial surgeon at the University of Greifswald in Germany, spent nearly a month studying the Carnegie embryos to learn better surgical techniques. “Understanding facial development is important for better understanding how to do cleft surgery in the right way,” says Breitsprecher. “There are different opinions about how to select the skin incision points. I found my answer there, and I never would have found it in the literature.” Other surgeons, physical anthropologists, and the dying breed known as anatomists also have used the collection extensively.

    The museum—which is famous for such macabre displays as a leg in a jar and an arthritic skeleton in a rocking chair—is planning two offerings in late October to tie into the birth of the Visible Embryo. One is a new exhibit titled “From Conception to Birth” featuring photographs by Alexander Tsiaras of embryos in the collection (see above), and the other is an overhaul of its long-standing exhibit on human development, which will include more embryos and fetuses at various stages. For those who can only visit the museum in cyberspace, log on to for a tour of the museum and a link to the Visible Embryo Project.


    One Year After: Tighter Security Reshapes Research

    1. David Malakoff*
    1. With reporting by Erica Goldman.

    When the University of Louisville in Kentucky drew up floor plans for a $48 million science building to house its chemistry, biology, and engineering departments, officials gave serious thought to placing faculty members' offices next to their labs. The layout promised greater convenience and efficiency over the traditional separation into administrative and research spaces. After 11 September, however, convenience and efficiency gave way to security: Offices and labs would be put in separate wings, so that students who might not have clearance to work in a lab could still meet with their professors.

    Across the country, in hundreds of ways both large and small, U.S. academic researchers are feeling the effects of that catastrophic day on their ability to carry out science. The airplane hijackings, and subsequent anthrax mail attacks, have triggered sweeping changes in the regulatory environment on campus. Next week, for instance, universities and other research facilities must notify the federal government if their researchers possess any potential bioweapons—the first step in registering users of such so-called select agents (Science, 31 May, p. 1585).

    In the meantime, the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, has already announced proposed changes to its list. In the weeks ahead, that will be joined by a similar compilation of potentially lethal agricultural materials to be issued by the U.S. Department of Agriculture. Then there are pending rules for securing the labs where these agents are kept and for restricting the pool of scientists allowed to work with them, for example, by excluding felons and researchers from so-called terrorist states.

    “We're all getting used to a new landscape for research,” says molecular biologist Nancy Martin, vice president for research at Louisville, one of many schools scrambling to adapt. “It will take some doing.”

    Regulatory heft.

    Complying with new bioterror research rules is keeping Cheri Hildreth Watts of the University of Louisville busy this fall.


    Eager to plug security gaps, Congress and agency officials have set tight deadlines for complying with the new regulations. On most campuses, a disproportionate share of the burden has fallen on the university's environment, safety, and health (ESH) officers. At Louisville, that means Cheri Hildreth Watts, whose office is piled high with new, security-related paperwork.

    For 15 years, Watts has led the university's efforts to comply with a growing list of federal ESH requirements. A nationally recognized expert on the subject, she helped found a 50-university group that develops and shares best practices. But even she is having a hard time keeping pace with the government's rush to regulate potential bioweapons.

    The first step requires every life sciences researcher to disclose to university officials and the government by 10 September whether they are working with any of about 40 agents that could be potential bioweapons, such as plague or anthrax. At Louisville, that meant getting hundreds of scientists and graduate students to interrupt work and vacations and crack open storage freezers, then fill out the necessary forms. The next step, to be completed early next year, will be for researchers to formally register their collections with CDC.

    “It's been a deluge, a whirlwind, and it's not going to stop,” says Watts, noting that government agencies have issued six regulatory notices on the subject in recent months. The welter of paper has left university officials to ponder questions such as whether live poisonous snakes and lizards have to be reported because they manufacture regulated toxins (they don't). “The incentive to get it right is very high,” she adds, because universities and researchers who don't comply face stiff, potentially criminal, penalties—as a graduate student at the University of Connecticut recently discovered (Science, 2 August, p. 751).

    Support from senior Louisville administrators—including Martin and graduate dean Ronald Atlas, a nationally known bioterrorism expert who helped shape the new law as president of the American Society for Microbiology—has helped the process go “pretty smoothly” on her campus, Watts says. Louisville biochemist Russell Prough says it took him “just a few minutes” to confirm that he didn't deal with any of the agents in his four-person lab. But some scientists chose to avoid greater paperwork by disposing of potentially problematic research materials. “They decided they didn't want to have to fill out the forms,” she says.

    Overall, Watts estimates that fewer than two dozen Louisville researchers currently work with the regulated agents. Still, the university might develop new policies and rules that govern their conduct in the lab and go beyond current federal rules. There is already talk of a policy that would require a witness to certify that a researcher has properly destroyed regulated materials, for instance. More thorough and frequent laboratory inventories could also become routine, and some labs might have to be remodeled to meet security requirements. “We're not done; this will be a moving target,” Watts predicts.

    Timely rules?

    University of Louisville biochemist Russell Prough (left) says complying with new bioterror rules was a snap but that the growing number of federal regulations is eating into research and teaching time.


    Other universities report similar discussions. Although a half-dozen institutions contacted by Science say that the notification process is going relatively smoothly, others report some bumps in the road. At Stanford University in Palo Alto, California, for instance, biophysicist Steven Block thinks that ESH officials have gone way too far in asking researchers to inventory “any and all biological agents and biological toxins that are used or stored” on campus. The request exceeds legal requirements, doesn't inform researchers about potential legal ramifications, and is maddeningly vague, he complains. “Does this mean [I have to report] even house plants or home-brewed beer? How about grad students?” he asks, only partly in jest.

    Lawrence Gibbs, Stanford's associate provost for ESH, says the inventory is a “prudent measure” to create a baseline for future biosafety planning. “We don't want to have to poll the faculty every 2 months because of inconsistencies,” he explains. Other faculty members applaud his strategy. “The [broader] survey was absolutely the right thing to do,” says John Boothroyd, chair of Stanford's microbiology department. “The fewer requests, the better.”

    Universities are also pondering how to collect and store the information securely. Some have established supposedly hacker-proof Web sites and e-mail accounts. But other schools, including Louisville, are insisting that researchers deliver their signed notification forms in person. “We are not allowing anything to go through mail or e-mail,” notes ESH director Karen VanDusen of the University of Washington, Seattle.

    Virtually every university official Science contacted also voiced concern about unrealistic deadlines. “It is putting the squeeze on everyone,” says L. Todd Leasia, director of the office of research safety at Northwestern University in Evanston, Illinois. And Gibbs worries about the uncertainties over how to handle certain classes of agents such as genetically engineered proteins. “The CDC needs to clarify its guidelines,” he says.

    That's expected to happen in the next few months as government agencies issue policies on a variety of research-related security issues. In the meantime, Watts and her colleagues are preparing to ride out the continuing aftershocks from last year's attacks. “It's certainly given us a lot to think about and a lot to do,” she says.

    It's also changed the nature of her professional interactions. “I get invited to some pretty high-level meetings now,” she says. “Health and safety issues have always been important to universities, but now they are really in the limelight.”


    One Year After: Hunt for NIH Funds Fosters Collaboration

    1. Martin Enserink

    Picking the right name was important when infectious-diseases researchers at the University of California (UC), Davis, decided to join forces in an ambitious new center earlier this year. After several false starts, one name stuck: The Western National Center for Biodefense and Emerging Diseases (WNCBED). It might be a mouthful, but Frederick Murphy, who masterminded the nascent center, says that it's perfect for the post-11 September funding environment. “Western” locates it on the U.S. map, he says, and “national” proclaims its coast-to-coast ambitions. “Biodefense” demonstrates concern for protecting the country, and “emerging diseases” conveys the message that most disease outbreaks still have natural causes.

    Such attention to detail is essential when the stakes are so high. Congress is now debating President George W. Bush's request for $1.75 billion for the National Institute of Allergy and Infectious Diseases (NIAID) to fight bioterrorism. The 2003 request, a 2000% increase from the institute's pre-11 September budget for bioterrorism, is a direct result of the terrorist attacks on New York City and Washington, D.C., and the subsequent anthrax mailings in several states. It's also an unprecedented commitment to increase understanding of organisms that can be fashioned into terrorist weapons. The budget dwarfs the $133 million requested by the Defense Advanced Research Projects Agency for its biological warfare defense program; another key agency, the Centers for Disease Control and Prevention, wants $1.6 billion next year primarily to beef up public health infrastructure and buy drugs and vaccines. That leaves NIAID as researchers' favorite funding agency, and getting a slice of the pie has become almost a full-time job for some.

    With advice from several expert panels, NIAID has begun to work out what it hopes to do with its vastly expanded war chest. Its wish list covers everything from basic research on potential bioterrorist weapons to vaccine and drug trials. There's a plan to fund one or two genome centers to sequence the DNA of microbes and the insects that transmit some of them. There will be bioinformatics centers to keep track of all the data and help identify drug and vaccine targets. There's also money to develop new small-animal and primate models of bioterrorist threats.

    Grand plans.

    The University of California, Davis, hopes the new NIH program will help fund a $190 million bioterrorism research center, including a biosafety level-4 lab.


    The most coveted prizes, and the cornerstone for the Administration's entire bioterrorism program, is a series of centers of excellence for research and training, one in each of 10 preselected regions. Some of the centers will be affiliated with one of half a dozen new biosafety level (BSL)-3 and -4 facilities, the so-called regional biocontainment laboratories, that are also part of the initiative. “There's a tremendous amount of buzz about this,” says microbiologist Joel Baseman of the University of Texas Health Science Center at San Antonio. “We're all eager to participate.”

    The winners, it's safe to say, will have engaged in an unusual degree of coordination among traditional rivals. Colleagues say that WNCBED, a proposed collaboration between UC Davis, California's Department of Health Services, and Lawrence Livermore National Laboratory, is a very strong contender. But the competition will be stiff. Across the country, similar centers with similar-sounding names have sprung up “like mushrooms after the rain,” says virologist C. J. Peters, who himself directs the new Center for Biodefense at the University of Texas Medical Branch (UTMB) in Galveston—and they all hope to cash in.

    Exactly how much money will be available next year is still uncertain. A Senate panel has appropriated $263 million less for NIAID than the president requested—a reduction that would cut into the proposed biodefense effort, NIAID Director Anthony Fauci said last week. The program could also change if, as Bush has proposed, control over the money shifts to the proposed new Department of Homeland Security. But Fauci says he has already worked closely with that department's progenitor, the Office of Homeland Security, and doesn't expect major course changes.

    The initiative attracting the most attention is NIAID's plans for the regional centers of excellence and biocontainment labs. A daylong meeting last month to explain the proposal drew a packed house of 350 scientists and administrators, comprising a veritable who's who in U.S. infectious-diseases research. NIAID would like to spend $190 million next year on the centers and labs and double that amount in 2004. Each center would get $6 million to $10 million a year for up to 5 years.

    NIAID hopes that the competition will unify a field that traditionally has been shaped by a large number of small groups. The new centers will become part of a national network, subject to close oversight by the agency. NIAID officials would prefer just one application from each region, submitted not by an individual center but by a consortium institutions with a common research theme and a long-term strategy. “We're not looking for [proposals from] a bunch of researchers who happen to be in the same place,” says Rona Hirschberg, who coordinates the centers-of-excellence program.

    The process has triggered “a frenetic dance” of conference calls, meetings, and one-on-ones, says Jacqueline Cattani, director of the University of South Florida's (USF's) Center for Biological Defense in Tampa, along with plenty of speculation about who's in and who's out. “It's natural selection at work,” says John Baker, an associate dean at Michigan State University in East Lansing.

    Building boom.

    The University of Texas Medical Branch in Galveston is already building a new biodefense lab but hopes for additional federal funds.


    In most regions, researchers at the major universities are calling the shots, with lower ranked institutions pleading for a place at the table. In region 4, for instance, which includes eight southeastern states, universities such as Duke, Emory, and the University of North Carolina are expected to team up on an application. Cattani's center at USF is not a major player, she says, but its expertise in applied research areas such as biosensors and test protocols might win it a spot on the application.

    In region 6, which includes Texas and four neighboring states, Galveston has taken the initiative. UTMB's David Walker will be the principal investigator for the center-of-excellence proposal. Last week he sponsored a meeting for 16 interested parties to discuss each team's role.

    In the mid-Atlantic region, former Soviet biowarrior Kenneth Alibek says he's still undecided whether the Center for Biodefense he heads at George Mason University in Fairfax, Virginia, should join the band of heavyweights currently discussing an application. The group, which includes Johns Hopkins University and the University of Maryland, talks about emphasizing vaccines, he says, whereas Alibek is more interested in host-pathogen interactions and developing new therapeutics against bioterrorist threats.

    NIAID officials say all is not lost for those who don't make it into a center—or whose application is passed over next spring when a review panel will select the first handful of proposals. Although they're very important, the centers of excellence and biocontainment labs will account for less than 15% of the funds available next year, says Fauci: “People have to remember that the vast majority of the money will go into traditional grants.” A second competition will take place in 2004, and perhaps a third round, until NIAID has chosen one center for each of the 10 regions.

    But most bioweapons researchers assume that whoever gets funded next year will have a head start on the rest of the field, so it's important to make a smashing impression now. Murphy has already hired an architect to conceptualize a new $190 million lab with a major BSL-4 facility, and he hopes that UC Davis's renowned medical entomology lab, a primate center, and ties to other labs will provide the type of “linkages” that NIAID has described. “We're listening closely to the words coming out of Washington,” Murphy says.


    Profile: Janet Shoemaker, Shaping the Politics of Bioterrorism

    1. David Malakoff

    It was a classic Washington moment: After a long and sometimes contentious congressional hearing on bioterrorism earlier this year, a harried staffer clutching a sheaf of papers sought out a crisply dressed woman chatting with reporters. “Here's the latest; let us know what you think,” he said.

    The invitation—to review a confidential draft of a bill to regulate research on potential bioweapons—is the kind typically extended to only a select group of the most influential lobbyists. And on the issue of regulating biological research in a post-11 September world, that group includes Janet Shoemaker, head of public affairs for the American Society for Microbiology (ASM).

    “[Shoemaker] is incredibly knowledgeable; we all turn to her for expertise,” says Anthony Mazzaschi, a lobbyist with the Association of American Medical Colleges in Washington, D.C. She's also politically savvy. Shoemaker “knows when to let an issue drop and where and when to stand and fight,” says Representative Billy Tauzin (R-LA), chair of the House Government Affairs committee, which crafted the bioterrorism bill that Congress approved in June. He credits her with having “a positive impact” on the legislation.

    A Minnesota native with degrees in history and public policy and a “longtime interest” in science, Shoemaker joined ASM 25 years ago and has headed its office of public affairs since 1989. In that job, she has become an expert on bioterrorism policy's impact on research and ASM's unofficial liaison to a government increasingly worried about potential bioweapons.


    Janet Shoemaker has helped make the American Society for Microbiology a major player in the bioterrorism debate.


    Since the 11 September and subsequent anthrax attacks, Shoemaker and ASM scientists have had to shift into high gear. They persuaded lawmakers drafting the antiterrorism Patriot Act, which passed last October, to exempt “bona fide” researchers from its harsh criminal penalties for possessing select agents. And they altered language barring all foreign scientists from working with the agents, limiting it to a ban on scientists from nations tagged as sponsors of terrorism.

    The Patriot Act wasn't the only instance of Shoemaker's ability to modify extreme proposals. When some lawmakers drafting the bioterror bill suggested banning all research on select agents, Shoemaker arranged for ASM scientists to explain why that idea would doom efforts to develop new treatments and vaccines. “[Shoemaker] had a major impact on the bill,” says George Leventhal, an ally and lobbyist at the Association of American Universities in Washington, D.C.

    That impact is unusual in the small world of science policy, notes Edith Holleman, a Democratic staffer on Tauzin's committee. “It's not as if members of Congress get up and say: ‘I have to respond to the microbiologists today,’” she says. Shoemaker has earned their respect, Holleman adds, by “always being responsive. When we ask for a position, we get a position.”


    New Lure for Young Talent: Extreme Research

    1. Robert F. Service

    Science funding agencies are letting students experience weightlessness in hopes of keeping them grounded in science

    HOUSTON, TEXAS—Eleven thousand meters over the Gulf of Mexico, Graylan Vincent and Karen Kennell are floating—or diving to Earth in a 3-kilometer free fall, depending on how you look at it. The University of Washington (UW), Seattle, undergraduates are inside a KC-135 microgravity research airplane, running a self-designed experiment in a lab that flies in a sinusoidal wave pattern to mimic the weightlessness of space. The plane belongs to NASA, which doles out a fraction of its flying time to undergraduates looking to experience science on the edge.

    Trying to hold himself steady, Vincent, a senior in aeronautical engineering and geology, hits a button on a laptop that's wired to a motor-controlled milling machine inside a Plexiglas cage. A half-inch (1.27-centimeter) drill bit whirs to life and slices through a slab of aluminum. For a few seconds, thousands of silvery shards hover aloft. They move as if in slow motion until Vincent flips another switch that turns on a converted Toro leaf blower, which blows the flecks into a mesh screen and out of the way.

    At 8000 meters, NASA pilot Stephanie Wells gently pulls back on the yoke. The lights dim, and Vincent and Kennell settle onto the floor of the white, padded interior of the Boeing 707. A couple of seconds later their bodies weigh twice normal as the plane pulls up to reverse its fall and climb to the top of its arc. A bell chimes softly, the lights come back on, and Vincent and Kennell get another chance to experience the sensation of weightlessness that only astronauts normally encounter. After a couple dozen of these parabolas, Vincent looks up with a big grin on his face. “This is awesome,” he says, bobbing over his equipment. “I can't wait to be on the space station.”

    On the fly.

    UW undergraduates Graylan Vincent (left) and Karen Kennell (front right) spend 25 seconds in free fall while running an engineering experiment aboard NASA's “Vomit Comet.”


    It's just the reaction NASA officials were hoping for. NASA, the U.S. National Science Foundation (NSF), and other science funding agencies are expanding adventurous undergraduate research opportunities in the United States and other countries in an effort to encourage students to choose careers in science and engineering. According to NSF's Science and Engineering Indicators, the number of U.S.-born students pursuing Ph.D.s in the natural sciences and engineering declined more than 20% in the 1990s, despite the nation's increasingly technology-based economy. Offering undergraduates an inside look at cutting-edge research has long been considered a promising way to stem that tide. And today, research experiences like this trip on the “Vomit Comet” are taking more and more students out of darkened basement labs and into extreme environments.

    Astronomy students, for example, have an opportunity through NSF to pursue galactic questions at the Cerro Tololo Inter-American Observatory in La Serena, Chile. The agency also sends students aboard oceangoing research vessels and on projects everywhere from Iceland to the South Pole. The Department of Energy offers several research stints, including one at its magnetic fusion facility at Lawrence Livermore National Laboratory in California. And the European Space Agency gives undergraduates access to a weightlessness-research aircraft like NASA's.

    According to Karolyn Eisenstein, who directs NSF's Research Experiences for Undergraduates program, there's more to these exotic research projects than adventure: “It's the opportunity to put students in the venue where the science is being done. That gives them an introduction to what the field is really like.”

    Career boost

    Do such programs work? It's hard to know for sure, says NSF's acting director of undergraduate research Norman Fortenberry, because so many factors influence career choices. Nevertheless, he says, many people are convinced that “these experiences elicit interest in science and technology and reinforce students' decisions to pursue careers in these fields.”

    Donn Sickorez, who heads NASA's student research program, doesn't track the career paths of student fliers. But he does know that none of the 1230 students who have gone through the program since its inception in 1995 has gone on to apply for astronaut training. That's not surprising, because the program is young and so are the alumni. Still, Sickorez says that he has anecdotal evidence that student fliers have stuck with careers in science. “That's our goal,” he says.

    Joel Lohrmeyer, a member of the UW team who just completed his bachelor's degree, is convinced that his research adventure will lend cachet to his résumé: “It was great for me as someone who is going into the job market.” He imagines someone noticing and saying, “‘Wow, he took the initiative to be involved in this competition and has experience with NASA.’” Lohrmeyer sees “a definite benefit.”

    Not just a joy ride

    Setting your heart on joining exotic research projects is problematic, though: They can be hard to come by. Vincent, Kennell, Lohrmeyer, and their fourth teammate, Holly Devlin, spent over a year preparing their experiment. They had to come up with an idea, submit a proposal, pass a competitive peer review at NASA, raise money, design the equipment, put it together, make sure it passed NASA's rigorous safety precautions, and, of course, collect data on the flight—all work for which they received no course credit. “I was determined to get on that aircraft,” says Vincent, who first heard about the program in high school. His flight, he says, “was the culmination of 6 years of thinking about it, 2 years of planning, and 14 months of actually working on it. It has been a lot of work. But it was every bit as exciting as I had hoped.”

    A cut above.

    In a high-altitude test of drilling in zero gravity, flecks of blue wax hover around a robot-controlled milling machine until a blower whisks them away.


    The UW team's experiment, Lohrmeyer explains, was designed to test the feasibility of making precision machine parts in microgravity. A machine shop could come in handy aboard the international space station, where astronauts could use it to make replacement parts long before a spare could be sent from Earth. But weightlessness could raise havoc with the machining process. Whereas shards are pushed to the side of the cutting blade in a normal environment, in weightlessness they might float in the way, reducing performance. The UW team wanted to see if this happened aboard the KC-135. And although the cuts look fine, the UW team is now using a variety of precision metrology techniques to see whether there was any difference between those made at zero gravity (0g), 1g, and 2g.

    Not all experiments aboard the KC-135 work out so well. Desiree D'Orazio, a mechanical engineering student at Rowan University in Glassboro, New Jersey, for example, was a member of a team whose experiment didn't go as planned. It was designed to determine whether weightlessness slows the diffusion of heat, a condition that could affect countless pieces of equipment in space. The apparatus consisted of a water-filled tank with a wire inside and a speaker nearby. When heated, the wire generates air bubbles on its surface, which were supposed to be dislodged by the speaker's sound waves. But during the students' flight an electrical connection to the speaker failed, limiting the amount of useful data they could collect. “It was somewhat disappointing,” D'Orazio says. “But I learned that complex research experiments rarely work the first time.”

    All is not lost. D'Orazio says she and her team will likely propose a modified experiment in the fall. “I definitely want to try this experiment again next year,” she says—not just for the data, but for another shot at being weightless. “It was better than anything I could have imagined.” Vincent, too, says his team might consider submitting a revised proposal on its experiment. Then again, he says, he might look for another adventure altogether: “I might have to see if I can get on one of those oceanography research programs.”


    An Ecological Oasis in the Desert

    1. Jocelyn Kaiser

    TUCSON, ARIZONA—Amid dry hills dotted with saguaro cactuses, more than 3500 ecologists gathered here from 4 to 9 August for the 87th annual meeting of the Ecological Society of America (ESA). The meeting, held jointly with the Society for Ecological Restoration, included sessions on everything from grassland restoration to the interplay of aphids, bacteria, and wasps.

    A Gutsy Defense Against Killer Wasps

    Many pea aphids suffer a grisly fate early in life. Parasitic wasps swoop down on the tiny sap-sucking insects and inject them with an egg; the larva transforms the maturing aphid into a nutrient-stocked cocoon. Some aphids, however, are able to ward off this deadly attack by using a little-known bacterium living in their cells.

    The study—the first to show that symbiotic bacteria can confer resistance to an enemy—sheds light on the hidden world of bacteria that dwell inside insects. “This is one more example of how important these bacteria are in insects' lives,” says Richard Stouthamer, an entomologist at the University of California, Riverside. Agricultural scientists could also translate the knowledge into better ways to control insect pests.

    Over the past dozen years, scientists have used molecular techniques to uncover many bacteria that live only inside the cells of insects. For example, some Wolbachia bacteria manipulate their hosts' sex lives for their own benefit by forcing the host to produce only females, the sex that transmits Wolbachia. In other cases, there's a tangible benefit to the host. Aphids depend on Buchnera bacteria for nutrients such as amino acids that are lacking in their plant diet.

    But another set of bacteria has long presented a mystery. Among these so-called secondary symbionts are members of the gamma proteobacteria clade—often found in female pea aphids—that inherit the microbes from their mothers. “What maintains this menagerie is a puzzle,” says Charles Godfray of Imperial College at Silwood Park, U.K. Kerry Oliver and co-workers Jacob Russell, Nancy Moran, and Martha Hunter of the University of Arizona, Tucson, wondered what sustains the relationship between the aphids and the secondary symbionts.

    Secret weapon.

    A kind of symbiotic bacteria found in pea aphids (smaller ovals at right in micrograph) help the aphids resist parasitic wasps.


    The researchers knew that pea aphids vary in their ability to resist a major enemy, a parasitic wasp that hijacks aphids to raise its eggs. To find out if the symbionts help protect the aphids, Oliver described at the meeting how the Arizona team used a minuscule needle to inject bacteria-free aphids with three varieties of gamma proteobacteria: T-type, R-type, and U-type. Each type offered the aphids various degrees of protection. Although U-type conferred no resistance to the wasp larvae, the larvae in aphids infected with R- or T-type were up to 41% more likely to shrivel up and die.

    After surviving a wasp larvae attack, aphids with R- and T-type bacteria produced more offspring over their lifetimes than did uninfected aphids. The Arizona team is not sure how the bacteria protect aphids, although Oliver speculates that they might, for example, produce a toxin that poisons the wasp larvae or stimulate a deadly immune response.

    Other insect labs have observed links between bacteria and host defense, says Godfray, but the new study is the first to “demonstrate unambiguously [that] the bacteria are responsible.” Oliver adds that the bacterial defenders could help explain why wasps don't always control pea aphid pests in U.S. alfalfa and clover fields.

    Swamping the Opposition

    Exotic species are a global nightmare, second only to habitat destruction as a cause of species loss. California is a striking example: Mediterranean grasses and forbs have run riot over 9.2 million hectares of native grassland, nearly a quarter of the state. A study presented here at the meeting has uncovered the apparent secret to the California invaders' success: a dearth of native seeds.

    The findings suggest that bringing back native grasslands could be as straightforward as overwhelming exotics with native seeds. “It may be possible to restore native grasslands by reversing the temporary advantage that the exotic species seem to have,” says ecologist Andrew Dobson of Princeton University in New Jersey. Others caution that attempts to carry out such blanket seeding have often failed. “It's an interesting and unusual result,” says Kevin Rice of the University of California (UC), Davis, “but the question is, how far can you extrapolate it.”

    California's grasslands became a battleground when exotic plants—hitchhiking as seeds on European settlers and their livestock—spread like wildfire in the late 1800s, probably abetted by grazing and drought that knocked down native plants. In addition to threatening to drive certain native species to extinction, the interlopers, which grow more densely and have shallower roots than the natives, increase fire risks and alter ecosystems by changing nutrient cycling.

    Vanquished invaders.

    At this reserve dominated by exotic grasses, adding lots of native seeds to plots allowed native grasses to return.


    Eric Seabloom of the National Center for Ecological Analysis and Synthesis in Santa Barbara, California, and his co-workers—Jim Reichman of UC Santa Barbara and Stan Harpole and David Tilman of the University of Minnesota, Twin Cities—wanted to find out how easily fields of annual exotic grasses and forbs can be converted to native perennial grasslands. They tested three possible reasons for the invaders' success. First, the exotics might dominate resources such as sunlight and water; second, they might be winning out because the sparse natives produce too few seeds to retake the fields. The third possibility was that grasses—whether native or exotic—establish a beachhead from which they aren't easily dislodged, Seabloom says.

    In a 5-year series of experiments on plots in former crop fields at Sedgwick Reserve near the Southern California coast, Seabloom's team ruled out the first and third possibilities. Mixtures of exotic annuals such as black mustard, ripgut grass, and soft chess used less water, nitrogen, and sunlight than a mix of five native perennials such as California brome and purple needlegrass. And the natives were able to retake patches of exotic grasses if the researchers planted more native seeds, showing that the exotic plots weren't impregnable. Seed abundance was the crucial factor, Seabloom says.

    The next step is to figure out how to parlay that knowledge into a viable restoration strategy. Californians have tried to restore grasses by adding lots of native seeds, but few seedlings survive, says Rice. Seabloom's plots were “pretty artificial,” because exotics had not built up seed banks in the soil, says Carla D'Antonio of UC Berkeley. “These are not your typical grazed grasslands with tens of thousands of seeds per meter squared,” she says. And the influence of seed abundance might not be as great as in locations with climates different from those tested in Southern California, Rice says.

    Seabloom agrees that “we definitely need to do follow-up work in different conditions,” including in fields where exotics have been growing for a long time. But even if his team hasn't found a quick fix for restoring grasslands, the experiment might lay the groundwork for more sophisticated approaches. “By understanding the mechanisms,” Seabloom says, “you're always going to be better off.”


    Getting Down to Bare Wood and Overcoming a Barrier

    1. Anne Simon Moffat

    ORLANDO, FLORIDA—From 23 to 28 June, roughly 1000 scientists, half of whom came from outside the United States, gathered here to learn about the latest research on plant biotechnology. Among the new findings: a gene that might make it easier to regenerate whole plants from cultured cells and an analysis of the loblolly pine genome that might help researchers identify the genes that guide plant development.

    Loblolly Pine Genome Analyzed

    To the casual observer, the model plant Arabidopsis thaliana and the loblolly pine (Pinus taeda L.) have little in common. Arabidopsis is a tiny flowering annual with a life cycle measured in weeks; the loblolly pine, a commercially important tree that provides 58% of the timber harvested in the United States, grows as high as 50 meters and can live for centuries. Yet new results described at the meeting by Ronald Sederoff, a tree molecular geneticist at North Carolina State University (NCSU) in Raleigh, indicate that the genomes of these two species are surprisingly alike.

    “We've said all along that Arabidopsis is a model for flowering plants,” says Eliot Meyerowitz, a plant molecular biologist at the California Institute of Technology in Pasadena. “It may go further than that” and serve as a model for all seed-bearing plants, including more primitive species such as the loblolly and other conifers that don't have flowers.

    Sederoff, graduate student Matias Kirst, and their colleagues, both at the NCSU Forest Biotechnology Group and the Center for Computational Genomics at the University of Minnesota, Minneapolis, came to their conclusion by producing and analyzing expressed sequence tags (ESTs) from the loblolly pine. ESTs are DNA copies of fragments of an organism's messenger RNAs and thus represent the genes active in its tissues. To better understand the gene changes that distinguish woody plants such as the loblolly from herbaceous ones such as Arabidopsis, the team focused primarily on ESTs from the pine's wood-forming tissue.

    The researchers ultimately produced and sequenced some 60,000 ESTs, representing about 12,000 genes, roughly one-half of the total number in Arabidopsis. They found that 90% of the loblolly genes apparently have counterparts in Arabidopsis. “The closer we looked, the fewer differences we found” between the Arabidopsis and loblolly pine genomes, says Sederoff. Given that the last common ancestor of the two species dates back roughly 300 million years, he adds, the finding indicates that the protein-coding portions of their genomes have been highly conserved.

    The finding suggests that a relatively small number of genes could determine whether a plant species grows as a tall, woody tree or a small, herbaceous plant, Sederoff notes. This difference might also be due to the influence of regulators, which can mediate between environmental factors and functional genes, turning them on and off as needed.

    Genetic cousins?

    Despite its normal herbaceous nature, Arabidopsis, like the loblolly pine, has the genetic potential to produce wood, here used to make a tiny Adirondack chair.


    Indeed, there is evidence for that idea. Several years ago botanist Simcha Lev-Yadun of the University of Haifa, Israel, found that he could trigger the formation of woody roots and stems—albeit matchstick-sized ones—in Arabidopsis by pruning the flowers every day. Two years ago, molecular biologist Eric Beers of Virginia Polytechnic Institute and State University in Blacksburg repeated the work, using the resulting wood to build a miniature Adirondack chair.

    This shows that Arabidopsis does in fact carry the genes for wood formation, as suggested by the Sederoff team's results. It should now be possible to track down those genes and see how they are controlled in a species much more amenable to study than the majestic loblolly pine.

    Gene Might Aid Plant Regeneration

    Researchers seeking to genetically engineer new plant strains often run into a major obstacle: how to grow whole plants from cells into which they have introduced a new gene. So far, that's been much more of an art than a science, as researchers have had to resort to laborious trial-and-error methods to find just the right culture conditions. Now, a new development might help solve this hitherto intractable problem.

    At the meeting, Qi-Wen Niu, a postdoc in Nam-Hai Chua's lab at Rockefeller University in New York City, reported that he and his colleagues have identified a gene in the model plant Arabidopsis that can, when overexpressed, cause ordinary somatic cells to develop into embryos. The result, Chua suggests, is like converting plant cells to stem cells. (The results also appeared in the May issue of Plant Journal.) The finding could help “transform cell culture studies from an empirical to a more targeted, experimental discipline,” says Indra Vasil, a plant biologist at the University of Florida, Gainesville.

    The gene, dubbed pga6 (for plant growth activation 6), is not the first one found to have this ability. About 5 years ago, Tamar Lotan, then working in the laboratory of John Harada at the University of California, Davis, found that overexpression of the lec1 gene has a similar effect, but the frequency of embryo production was low. In contrast, pga6 triggers the formation of copious numbers of somatic embryos that develop into fertile plants.

    Niu, Chua, and their colleagues, including Rockefeller's Giovanna Frugis and Jianru Zuo of the Institute of Genetics and Developmental Biology in Beijing, discovered pga6 using a method called activation tagging. This involves introducing into plant cells foreign DNA containing a regulatory element known as a promoter that enhances gene activity in response to chemicals, the hormone estradiol in the Chua team's case.

    The researchers then exposed cells containing the DNA to estradiol and looked for any changes produced when genes near the inserted promoters increased their activity. Some of the transformed cells produced numerous somatic embryos—an effect the group traced to the pga6 gene. The researchers also showed that when they turned off pga6 expression by removing estradiol from the culture medium, the somatic embryos germinated into morphologically normal and fertile plants.

    Further work by Chua and his colleagues showed that pga6 is identical to the WUSCHEL gene, which was originally identified about 5 years ago by Tom Laux's team at the University of Freiburg in Germany. Laux and his co-workers found that WUSCHEL is important for normal development of zygotic embryos—those produced sexually when pollen fertilizes a plant's ovules—but they did not find any relation between WUSCHEL and somatic embryo formation. Now that the Chua team has made the connection, plant researchers might be able to increase the efficiency of their genetic engineering efforts by temporarily upregulating the pga6 gene in the plant cells they are transforming.


    NSF's Ark Draws Alligators, Algae, and Wasps

    1. Jennifer Couzin

    Evo-devo researchers are thrilled about NSF's new grants for genetic studies of neglected species, although there are too many species and not enough money

    Scott Edwards treks around the world seeking songbirds. He's especially passionate about house finches, a focus of his ornithological research at the University of Washington, Seattle. So how did he end up last month as principal investigator on a genetics project involving a jumble of reptiles—including the relatively obscure (and nearly legless) worm lizard? The answer is simple: Edwards followed the rules set by the National Science Foundation (NSF), embracing species he doesn't normally study, and won a grant.

    NSF launched a novel competition a year ago, attempting to boost genetic research on organisms not deemed to be models of human biology and thus not usually funded by biomedical science. The agency decreed that most of the projects should be broad, covering as many branches on the Tree of Life as possible. The call for breadth brought together extended families of organisms that don't always fraternize. In Edwards's case, after reviewers had trimmed his plan, the flightless emu was left as the lone bird to tag along with lizards, a turtle, and an alligator.

    NSF's purpose in divvying up $6.4 million among 10 groups this way is to start building libraries of so-called bacterial artificial chromosomes (BACs) for detailed genetic studies of neglected species. BACs are useful for storing and cataloging DNA, essentially as bits of genomes that have been broken into manageable stretches, tagged, and inserted into bacteria. Biologists use BACs to examine genes, compare whole genomes of two or more organisms, and fill the gaps in existing gene sequences. Winners will use the money to pay for BAC libraries covering organisms of interest.

    The NSF grant competition electrified a diverse set of biologists and yielded an array of potential new genome projects. The species that came flying, swimming, and slithering out of NSF's award chute last month range from Edwards's worm lizard (Amphisbaenia alba) to a butterfly (Heliconius erato) and a tiny crustacean with a transparent body (Daphnia pulex). A study of two ancient marine animals, led by Rob Steele of the University of California, Irvine, seeks to probe the development of the first multicellular organisms, looking in particular at how and when a family of regulatory genes, called HOX genes, evolved. Another, led by Dina Mandoli of the University of Washington, Seattle, will explore genetic diversity in a range of plants, and a third, led by Marian Goldsmith of the University of Rhode Island, Kingston, is comparing genes that govern wing patterning in two moths and a butterfly.

    Still, $6.4 million goes only so far. Although NSF initially hoped to fund BAC libraries for 100 organisms—the cost of each depends on the size of its genome—money ran out after 63. Like garnering an invite to the Oscars, earning a spot on that final list demanded lots of politicking and a little luck, which sometimes failed to materialize.

    Artful gambits

    The field of evolutionary and developmental biology—or “evo-devo,” as it's often called—isn't accustomed to glamour contests. If there's one thing that irks the evo-devo community, it's the unending vanity of high-stakes biology. Being human, “we tend to devote our funds to the organism we care most about, which is us,” says Jeanne Romero-Severson of Purdue University in West Lafayette, Indiana. Biologists interested in nonhuman evolution are used to being ignored. They aren't mobbed at cocktail parties, for example, especially if it emerges that their work revolves around an obscure species of beetle. Nor are they sought out by the National Institutes of Health (NIH) unless their research can be tied to saving lives. (NIH earlier this year pledged $7.5 million over 3 years for 30 BAC libraries, most of them mammals and all connected in some way to human health.)


    The apple maggot fly didn't make the cut, but the American alligator was among 63 winners.


    With a mission to fund basic sciences, NSF was persuaded that coordinated genetic studies of overlooked species would provide valuable evolutionary insights. A workshop in September 2000 brought together the evo-devo set along with evolutionists studying the Tree of Life. The group resolved that creating BAC libraries—relatively cheap to assemble and useful to a broad swath of biologists—should mark the beginning of such efforts. BACs are good raw material for genetic maps and a starting point for whole-genome sequencing, says Richard Gibbs, director of the sequencing center at Baylor College of Medicine in Houston, Texas.

    Once NSF set the rules for its BAC funding a year ago, biologists reached out to colleagues they chatted up regularly and in some cases forged new alliances. Jeffrey Feder, a biologist at the University of Notre Dame in Indiana who adores the black-and-white-striped apple maggot fly, jumped in with Romero-Severson, who's also passionate about flies, or Diptera, and David Stern of Princeton University in New Jersey, who's fascinated by a type of aphid. They focused on their favorites but concluded that NSF's rules demanded some affirmative action. In addition to six species of fly (including the apple maggot) and an aphid, they tossed in six other insects they had not studied, including a beetle, a wasp, and a grasshopper. Three weeks of slaving over the grant proposal met with bittersweet results: Five of their affirmative-action recipients were blessed with $700,000 in funding but not their precious Diptera or aphid. “That caused great consternation,” says Feder, although he's still grateful. Romero-Severson adds: “The Nasonia [wasp] people are thrilled.”

    Edwards, the University of Washington ornithologist, also encountered partial disappointment. His grant proposal, which included four birds and six other species in the Reptilia class, was cut down in size, as were other awards. “The ornithologist side of me was a bit chagrined,” because only one bird was approved, he says. But he admits that, genetically, birds seem relatively uniform, whereas reptiles “are a huge black box.” Still, Edwards's $1.1 million award is the largest he's ever received; his giddiness eclipses any regrets.

    Even those who lost out might agree that NSF faced a daunting task in selecting a handful of organisms from the millions of possible candidates. Indeed, researchers at the planning workshop questioned whether it made sense to follow the traditional grant process. One evolutionary biologist who attended, Greg Wray of Duke University in Durham, North Carolina, recalls suggestions that the entire community vote for its favorite organisms. Although he didn't consider that wholly unreasonable, he says, “you'd have to be careful you didn't get people stuffing the ballot boxes.” NSF rejected these unorthodox ideas and in the end used its standard process, although it “was a little hurly-burly,” says Wray, who also sat on the final review committee. “We had one [proposal] for 20 different fungi,” he recalls, “and we were comparing [that] to proposals that were going to pick one really cool organism.”

    NSF's goal, says Judith Plesset, overseer of the grant competition, was to favor branches of the evolutionary tree for which few resources existed. She hinted at why Romero-Severson's flies were spurned, noting that “we have sequenced Diptera”—specifically, fruit flies, or Drosophila melanogaster, a model species used by labs worldwide. There was an exception: a $600,000 grant covering 11 strains of rice, deemed worth funding even though a rice genome has already been sequenced.

    Now that the grants are out, BAC makers are racing to keep up. Almost none of the new NSF awardees will actually build the BACs themselves. The money will flow instead from investigators to the handful of scientists nationwide who can build the libraries.

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    “Everybody wants a BAC library, and many people think it's easy to do,” says Pieter de Jong, a renowned BAC builder at Children's Hospital and Research Center at Oakland, California, who's constructing libraries for both NIH and NSF. “Then they fall on their face.” De Jong's lab has doubled in size, to 25 people, in the last year as orders continue flooding in. He has streamlined the process so that one worker can construct a library in about 3 months, extracting and purifying the DNA and keeping each BAC as large as possible—at least 150,000 bases in length, on average. Building so many simultaneously remains challenging. But de Jong and other BAC builders say they're thrilled by the renewed demand and will keep pace. Virtually all the biologists plan to apply the BACs in their own research, although they might need extra funding to do so. NSF mandates that the BACs be freely available for at least 5 years following their completion.

    A shaky future

    With NSF's $6 million in start-up money lingering like a sweet taste, grant recipients are hoping that their select species will enjoy more blessings later on. “We foresee that these [species] can be used as leverage” to persuade NSF to fund more genomics work, says Goldsmith, whose BAC grant totaled $210,000. But she worries that the NSF project might be over. “We're asking [Plesset] what's next, and she's saying, ‘I don't have any more money.’” Plesset agrees that, for now, her treasure chest is empty. “At the moment, there's no commitment from the senior management at NSF to repeat this competition,” she says.

    That has some scientists grumbling about the program's stinginess: “The amount of money that the Enron guys walked away with is more than the NSF is able to devote to this,” complains Thomas Kaufman, a developmental geneticist at Indiana University, Bloomington, who didn't participate in the grant competition.

    And so, even as they revel in their windfall and dream about its future impact on the field, evo-devo researchers are ready to fight for more. “Our field is now sexy,” proclaims Romero-Severson. And she, along with many others, doesn't want to see this summer fashion slip out of style.


    Cave Diving on Asteroids

    1. Robert Irion

    Planetary scientist Dan Durda flies high, dives deep, and wants to be one of the first to touch the surface of an object beyond the moon

    BOULDER, COLORADO—Twilight is stunning from the rear cockpit of an F-18 jet, Dan Durda says. A vivid ribbon of red and violet lingers after sunset. The zodiacal light—sunlight reflected from dust in our solar system—arcs above the horizon, brighter than the Milky Way. Stars and planets glow without twinkling in the coal-black sky. Topping it off are the brilliant blue afterburners that propel Durda through the stratosphere, 15 kilometers high.

    These flights aren't just military joyrides. Rather, they are the most enjoyable part of Durda's wide-ranging research in planetary science. With help from NASA test pilots, he scours the twilight sky for asteroids that orbit closer to the sun than Mercury. No one knows whether such “vulcanoids”—named for a planet once thought to dwell there—exist, but he wants to be the first to spot one.

    Durda would happily spend all his time exploring nature at Mach 0.9. “Dan is one of those people where it's very hard to say what he does for a living,” observes planetary scientist Erik Asphaug of the University of California, Santa Cruz. At age 36, Durda is best known for creating painstaking models that have helped reveal how collisions shape the evolution of the asteroid belt, from the largest objects to the tiniest grains of interplanetary dust. He loves plumbing the depths of water-filled caves, and he is an accomplished space artist. He is a pilot himself and aspires to join NASA's astronaut corps.

    Indeed, Durda's overarching goal is to float along an asteroid's surface on the first human mission beyond the moon. “Dan would be spectacular,” says S. Alan Stern, director of the department of space studies here at the Southwest Research Institute (SwRI) and Durda's colleague on the vulcanoid search. Although government officials have been “stuck in Earth orbit for 30 years,” Stern says, Durda's future “is unlimited.”

    Cosmos and the space shuttle

    Durda's office at SwRI overlooks the jagged foothills of the Rockies. A plaque commemorating an asteroid named after him (6141 Durda) sits on a heater under the window. A spectacularly patriotic print of an F-16 jet that once hung in the hallway now decorates his wall after some SwRI staff members teased him that it was jingoistic. Rows of Post-it notes march across a computer table, marked with numerals precisely 2 millimeters high.

    Many aspects of his life are as precisely laid out as those numbers. “I absolutely am at my best and most satisfied when I have to think through a detailed plan before I start going through the operation,” says Durda, who has receding sandy brown hair, squarish wire-rimmed glasses, and a neat mustache. It's easy to imagine his 1.7-meter, 63.4-kilogram (5′7′', 140-pound) body wriggling through submerged channels. “For years I was stabilized at 132 pounds,” he says. “But last year I learned that for the F-18 ejection seat, you have to be 140 pounds, minimum. Otherwise, it can break your back.” Despite his hummingbird metabolism, he went to the gym and gained 3.6 kg of muscle mass.

    As long as he can remember, Durda has battled gravity. He and his childhood buddies in suburban Detroit made black-powder grenades from the cartridges of BB guns, lit them under rocks, and measured how high the rocks flew. After his parents moved to rural Alger, Michigan, Durda attended high school next to a cow field. Despite the bucolic setting, the veteran corps of teachers in Alger “had maxed out a beautiful science curriculum,” he recalls. “Astronomy, entomology, botany, water ecology—I took them all.” He dreamed of floating under the sea as a marine biologist, but that changed in 10th grade once he heard the late Carl Sagan expound on the wonders of the universe. “In the fall of 1980, a PBS series called Cosmos came out, and boom, that was it.”

    Hot jet.

    Dan Durda admires this model of an F-18, but he flies in the real thing to hunt for new asteroids close to the sun.


    Durda's fascination with the space program took deep root in graduate school at the University of Florida, Gainesville, where he met fellow student Dirk Terrell. The two became the “dynamic duo,” famed for their eerily synchronous thoughts and their repeated 6-hour car trips—27 in all—to Cape Canaveral to see space-shuttle launches. “We went to the first post-Challenger launch, and we were hooked,” says Terrell, an astrophysicist and computer specialist at SwRI. “It was a very emotional experience. It brought tears to my eyes.”

    “The thing that floored me was the color and intensity of the solid rocket-booster exhaust,” Durda says. “It's a deep crimson orange, as bright as the setting sun. And all around us was a sound like someone shaking huge sheets of corrugated metal.” After several launches, Durda divined the source: thousands of palm fronds, rattling in unison to the intense bass vibrations.

    Terrell and Durda also were captivated by Florida's vast networks of sinkholes and water-filled karst caverns, which they explored in increasingly ambitious dives. “I certainly didn't approve of it,” says Durda's adviser at Gainesville, planetary scientist Stan Dermott. “I thought he was doing it to prove to NASA that he could cope with ridiculously dangerous situations.”

    About a half-dozen people die in Florida's caves each year. But Terrell and Durda—who coordinates the International Underwater Cave Rescue and Recovery team in Arizona and Colorado—say they have never felt at risk because of meticulous planning. And deep in the tunnels, Durda says, “It's pure joy. The water in Florida caves is as clear as gin. The entrance of a deep sinkhole glows like a cathedral with shafts of teal and turquoise light. No photograph could capture the beauty of that.”

    Dust and hot rocks

    Dermott encouraged Durda to study the evolution of the solar system's minor bodies by taking into account all data about their sizes and bands of dust. Durda made his first mark by building the most detailed models yet of asteroid impacts, collisional histories, and dust formation. He infuses his models with data from experiments in which he blasts projectiles into real meteorites—a facet of Durda's work that, according to Asphaug, sets it apart from the purely theoretical constructs of many colleagues. “It was like holding a dirt clod in your hands,” Durda says about one experiment with a Russian meteorite. “It blew into dust, and we didn't even hit it that hard.”

    In the mid-1990s, Durda worked as a postdoctoral researcher under planetary scientist Richard Greenberg at the University of Arizona, Tucson. Using images from the Galileo space probe, the group dove into detailed studies of Ida, a potato-shaped asteroid. They explained how impacts dredged material from Ida's interior and splashed it across the surface. Incorporating Durda's work on collisions, the model also accounted for Ida's tiny satellite, Dactyl. “It all came together with that team,” Durda says. “It was the most satisfying thing I've done.”

    Geologist David Kring, also at Tucson, urged Durda to scale up his Ida model to the size of Earth and apply it to the sexiest crash of all: the dinosaur-killing asteroid impact 65 million years ago. The blast sprayed trillions of meteors that heated parts of Earth's atmosphere so fiercely that it would have been “like putting your head in an oven on broil,” Durda says. In a paper in press at the Journal of Geophysical Research—Planets, he and Kring compute where the heat would have been intense enough to ignite wet vegetation. The duo has conducted fieldwork in southern Colorado and elsewhere to expose charcoal deposits left by the resulting fires.

    His Arizona years also opened Durda's eyes to the world of space art. “He would come into the gallery, but he never bought anything,” says Kim Poor, owner of Novaspace Galleries in Tucson. “He would just look closely at the paintings and leave. It got annoying after a while.” But when Poor finally got a peek at Durda's early work, he saw immediately that “it was professional quality.”

    Durda began painting “rocks and balls,” canvases filled with objects floating ethereally in star-speckled skies. As his skills grew, he tackled more intricate spacescapes and dynamic renditions of objects smashing into each other. His painting of Pluto and its moon Charon (Science, 26 July, p. 495) has become the iconic image for a proposed mission to Pluto, led by Stern. Most recently, Durda has turned to landscapes that look like earthly vistas. “I make them space art by putting a planet in the sky,” he says with a chuckle.

    Tucson afforded Durda everything he wanted, save for the chance to soar. “Dan is an addict for airplanes,” says Stern. When Stern told Durda in 1998 that SwRI wanted a researcher for the world's only opportunity to do astronomy from high-performance jets, Durda leapt at the offer without even visiting Boulder.


    Durda's art sometimes mirrors his science, as in this painting of a head-on collision between bodies in the outer solar system.


    Since then, the pair has carried out increasingly thorough searches for the solar system's hottest asteroids. Many researchers doubt that vulcanoids have survived the sun's heat and other disruptions for nearly 5 billion years. However, some models—including Stern and Durda's—predict that scores of hardy bodies, from 1 to 10 kilometers across, might persist about halfway between Mercury and the sun. The researchers' main tool is a sensitive ultraviolet video camera attached to an 85-millimeter lens that fits in the cockpit.

    Soon, Durda and Stern hope to ascend to greater heights—nearly 23 kilometers—in the back of a U-2 airplane. There, the twilight sky will be darker still. “The two of us are on a vulcanoid jihad,” Stern says. “We're going to find them if they're there.”

    Caves near and far

    Only one siren could lure Durda from Boulder: the space shuttle itself. “I'd drop everything to go to Houston,” he says. “If NASA picked me, I'd be there for life.”

    During NASA's last selection round 2 years ago, Durda made the top 12% of astronaut hopefuls (playfully called “as-ho's” by the astronauts). In the next round, set for summer 2003, he hopes to make the final cut. His Tucson colleagues are pulling for him. “He'd be a terrific astronaut,” says Greenberg. “He's got intellect and a real level-headed competence, and he's enthusiastic about everything he does.” Adds Kring: “I can't think of anyone better prepared in the community.”

    Meanwhile, Durda keeps launching new ventures on Earth. For instance, he is awaiting word on his request for funding from a new NASA program called Astrobiology Science and Technology for Exploring Planets. He's part of a team led by robotics expert Bill Stone of Stone Aerospace in Gaithersburg, Maryland, that hopes to send an autonomous robot far into Zacotón Cenoté, a deep hydrothermal system near Mexico's gulf coast. The labyrinth claimed the world's top cave diver in 1994.

    “Nobody knows what the hell is down there,” Stone says. “It screams for robotic exploration.” Durda worked with biologists and engineers at SwRI and elsewhere on a robot that could recognize life forms—especially novel ones. He and Stone view the vessel as a prototype for exploring the subsurface of Mars or Europa's dark ocean.

    Durda also views the robot as a surrogate for his dreams of reaching space. “Moving around on the surface of an asteroid will require the same skills and techniques you need for cave diving,” he says. “Gravity is so low that we will float over the surface, not walk. It will require a lot of care and finesse to avoid stirring up dust.”

    Durda becomes animated when he thinks of the trailblazing science of such a mission—as well as the role he would play in telling a captivated public all about it. “I'm trying as hard as I can to position myself to be on that first crew,” he says. “It's obviously a long shot, but I would do it in a heartbeat.”