News this Week

Science  28 Nov 1997:
Vol. 278, Issue 5343, pp. 1283
  1. SPACE

    Germany's Bleak Future in Space

    1. Robert Koenig
    1. Robert Koenig is a writer in Bern, Switzerland.

    THIS YEAR, GERMANY FOUND IT COULD NOT SUPPORT A SEPARATE SPACE AGENCY AND FOLDED IT INTO ITS AEROSPACE RESEARCH CENTER. IF BUDGET TRENDS CONTINUE, SOME OF ITS BASIC SPACE SCIENCE MAY NOT SURVIVE, EITHER

    Cologne, GermanyIn the prosperous days of 1989, just a few months before the fall of the Berlin Wall, West Germany launched its own high-flying space agency to manage and boost the nation's space effort. Like a rocket with a flawed final stage, the new agency soared for a while, but ultimately ran low on fuel as the high costs of reunifying East and West Germany deflated the space budget and shifted national priorities. Last month, the short-lived agency—the Deutsche Agentur für Raumfahrtangelegenheiten (DARA)—was quietly merged with the German Aerospace Center (DLR), a national research center which will now also take over the job of managing Germany's space program.

    The newly expanded DLR—which has annexed most of DARA's former staff—wants to preserve the quality of German space research while cutting back on duplicative management costs. “If we cannot get more money for space, then we must find ways to get more space research for our money,” says physicist Walter Kröll, chair of DLR. “The new DLR can more efficiently deliver a high-quality German space program that will contribute to European and other international space projects.”

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    But German space science is hardly headed toward new heights. With government funding for the space program still shrinking, and a bigger slice of that pie going to the European Space Agency (ESA) and the international space station, domestic projects are getting squeezed. Researchers are also worried that the government is trying to promote applied space research at the expense of basic science. While Germany has pledged to continue its role in the international space station project, Kröll recently told NASA officials that Germany will be unable to pay for any cost overruns, and definitely will not contribute to a proposed international crewed space mission to Mars over the next 15 years.

    National vs. international

    Ever since Wernher von Braun and other top German rocket scientists surrendered to U.S. troops at the end of World War II and joined the U.S. missile development program, Germany has been trying to find its proper position in the constellation of international space efforts. After a slow rebuilding in the late 1950s, German space research began to blossom in the 1960s when its first cooperative efforts with NASA and other European nations took place. With the establishment of ESA in the 1970s, the ties between German and European space science have become increasingly close. “Major space projects are too expensive for a single European country. That's why ESA is crucial,” says Dietrich Lemke, a researcher at the Max Planck Institute for Astronomy in Heidelberg. “ESA has been a great success, both in terms of science and in terms of applications,” agrees German physicist Reimar Lüst, a former ESA director-general and a seminal figure in postwar German space science.

    Playing a major role in ESA does have drawbacks, however: It locks countries into fixed funding commitments for many years. Because of its tightening finances, Germany, along with other ESA members, such as the United Kingdom, has been pressuring ESA to cut management costs and work harder at making projects stick to their budgets. “It is a difficult exercise, but I am convinced that ESA can become more efficient,” says Kröll.

    However, the inflexible level of funding for European cooperation and the expensive space station project are already cutting into domestic space science projects. “If the current budget trends continue, it could lead to a situation where Germany won't be able to do much other than ESA projects—and even that poorly,” warns Reinhard Genzel, director of the Max Planck Institute for Extraterrestrial Physics in Garching. Genzel's institute, for example—which in the past has built entire research satellites on its own—might find such projects impossible if outside funding dries up.

    While Germany's annual space budget amounts to about $837 million, some 70% of that total ($577 million) is channeled straight to ESA for European space projects. As part of that commitment, Germany will spend nearly $1.5 billion on the international space station project—41% of Europe's total contribution—between now and the year 2004. That leaves about $250 million a year for Germany's national space budget, which pays for DLR's space activities and other programs formerly managed by DARA. But space scientists complain that only about a third of the national budget goes to basic research in fields such as astronomy, space plasma physics, and planetary exploration.

    According to German government statistics, Germany—which spends about 0.05% of its gross domestic product on space—trails far behind the United States (0.53%) and France (0.18%), and also ranks behind Britain and Italy (both 0.06%). Moreover, Germany spends a higher percentage of its budget on international space projects—and correspondingly less on purely national space research. “The total budget has been shrinking, and the sum available for space science has declined even more,” says Lüst.

    Basic vs. applied

    Another development that has disturbed basic researchers is the research ministry's initiative to increase the focus on applied space research and closer ties to German industry. That shift was outlined in a white paper, approved by Germany's Cabinet in July, that recommitted Germany to full participation in the international space station—a commitment that some German scientists question.

    “We are very concerned” by the ministry's increased emphasis on applied space science, says Genzel. “Basic research now accounts for only one-fifth of Germany's space budget, and real funding for that basic research has declined by more than 40% over the past 4 years. Any further shift of resources away from basic research could have serious consequences.” Genzel says a group of prominent German space scientists wrote to the research ministry last summer to express concerns about the shift of emphasis toward applied space research.

    In July, Research Minister Jürgen Rüttgers declared that “Germany will continue as a driving force in European space efforts,” but also will draw in industrial partners to help strengthen Germany's “technological and commercial competitiveness.” Kröll says he generally agrees with the need to focus on space projects with potential commercial value. But he does not believe that the new emphasis will hurt basic research. “In all three main areas of basic space-science research—extraterrestrial, microgravity, and Earth observation and the environment—German researchers play a prominent role, and will continue to do so,” Kröll says.

    However, because DLR is known mainly for its applied research efforts, some space scientists are concerned that DLR may have too much control of setting the direction of space research. Before last month's merger, DARA took the lead role in prioritizing space research projects, while DLR mainly conducted research. While Lüst credits DLR for its “high-class aeronautical research,” he maintains that Germany's best space research projects—such as the ROSAT X-ray astronomy satellite and its contributions to ESA's Infrared Space Observatory (ISO)—have emerged from Max Planck institutes or universities, with funding from national and ESA budgets. Lemke, who helped develop ISO, also told Science that his main concern with the direction of German space policy is “whether DLR will shift the emphasis too much toward applied science.”

    While DLR's scientists have done excellent work in such fields as Earth observation and microgravity research, much of its reputation is based on its applied research in areas such as communications, navigation, and robotics. Even so, Kröll and other scientists at DLR's sprawling research complex near Cologne emphasize that basic research plays a crucial role. According to Rupert Gerzer, a molecular medicine researcher who directs DLR's Institute of Aerospace Medicine, “we balance our activities in basic research and applied research.” While the institute focuses on medical research involving microgravity conditions, his scientists have also used lessons learned from monitoring astronauts in space to develop “telemedicine” techniques to connect remote patients with physicians.

    Station stasis

    To many German space scientists, the solution to the budget squeeze seems clear: Delay or scale back Germany's substantial commitment to the space station and divert that money to the national space effort. If it were still possible, “I would try to delay the space station in order to free more money for basic space science,” says Lüst, who had supported the space station as ESA's director-general from 1984 to 1990, at a time when Germany's space budget was growing.

    But the research ministry and Kröll say Germany will not delay or back away from its commitment to the space station. In fact, the federal Cabinet approved the decision in July to make the space station the central focus of Germany's space activities over the next few years. Even so, Kröll has made it clear to NASA that Germany “will not be able to increase our budget for the space station, under any circumstances. This project must stay on budget: A 20% overrun on our part might endanger the German space program.”

    Many German space scientists question the space station's value for scientific research, and Lüst also asserts that—despite the research ministry's desire for commercial applications—the station offers little commercial potential. But Kröll—while he cautions against overestimating the space station's direct commercial potential—believes the station “will offer tremendous opportunities for research” and that such research eventually will have commercial applications. Herwig Öttl, DLR's associate director for space programs, agrees: “The space station is a technological challenge as well as an investment in the future.”

    Meanwhile, for Germany's space scientists, more investment in the present would be appreciated. While Lüst says he worries about the budget trends, he is hopeful that “this difficult financial period will be overcome without great losses in talented young people. Germany has built a good research program over the last 30 years, and I hope we will be able to keep it.”

  2. SPACE

    France Brings Space Goals Down to Earth

    1. Helen Gavaghan
    1. Helen Gavaghan is a writer in Hebden Bridge, U.K.

    France has long been at the vanguard of Europe's space effort: It was the driving force behind the Ariane launcher program and the now-abandoned plans for a space plane to ferry European astronauts to and from the international space station and its European lab module Columbus. In the late 1980s and early 1990s, the French space agency (CNES) would see annual budget increases of 20%. But those heady days are now nothing but a memory. The French space program, like its German counterpart (see main text), has slid down the list of national priorities, and CNES is lucky to get a static budget from one year to the next. And it could get worse: Claude Allègre, the pragmatic new minister for research and education, whose remit includes space, has made it clear that, while his vision of France's role in space is substantial, it is much less grandiose than before.

    The political message from the new Socialist government is that space policy must fit with its broader objectives, such as reducing unemployment, monitoring and understanding environmental changes, and improving industrial competitiveness. Allègre appointed a new CNES director-general, Gérard Brachet, last June and, says André Balogh, a professor at London's Imperial College, French scientists generally believe he was brought in to temper the traditional French enthusiasm for space. Indeed, Brachet has some tough marching orders. These include less emphasis on crewed space flight, better management at CNES and the European Space Agency (ESA), continued commitment to Europe's new heavy launcher (Ariane 5), high-quality science, a strong Earth-observation program, and possible collaboration with NASA on a sample-return mission to Mars in 2005.

    Allègre has said France will honor commitments to the space station it made at a meeting of ESA's ministerial council in Toulouse in 1995 (Science, 13 October 1995, p. 224). France is due to contribute 27% of the $2.3 billion ESA is spending on the space station. But in an interview with Science, Brachet said there will be no extra money for the station in the future, and negotiations on the amount Europe pays toward the station's operations are likely to be tough. “We have no agreement yet on operation costs, and we are watching with care,” says Brachet. Already, France has signaled its retreat from crewed space flight by pulling out of a European project to develop a crew-transfer vehicle for the station. Says one seasoned observer who does not wish to be named: “Allègre would be very happy if the space station would just go quietly away. They've bought an expensive mortgage, and now they can't afford to go out for dinner. It's frustrating for them.”

    While the station is a frustration, Ariane 5 is still France's jewel. France has funded more than 46% of the $7.5 billion development costs of Ariane 5, and CNES manages the project on behalf of ESA. Allègre sees the launcher as a cornerstone of an autonomous space policy that would free France from dependence on the United States. The loss of Ariane 5's first flight last year (Science, 14 June 1996, p. 1579) shook the French establishment. “It really was their Challenger,” says one observer. Following the first successful launch last month, one more is needed for flight qualification, then Ariane 5 can be transferred from CNES to Arianespace for commercial operation.

    However, CNES is now roughly half a million dollars in debt to ESA because it borrowed from the agency to keep Ariane 5 on schedule when other countries, principally Germany, did not fulfill their commitments to the project in the early 1990s. Allègre has been outspoken about his annoyance over this debt, which, says Brachet, CNES is now beginning to pay off. Allègre has also criticized ESA for poor management and inefficiency. He has plenty of incentive to tighten its operations: France provides nearly one-third of the agency's budget. The feeling among ESA's two big funders—France and Germany—is that ESA is not operating to their best advantage, so CNES is now working with its newly enlarged German counterpart, DLR, to develop a European space strategy and to suggest ways in which ESA could evolve.

    The initiative comes at a time when Antonio Rodotà, ESA's new director-general, is carrying out his own agencywide strategy review in preparation for a ministerial council meeting next June (Science, 5 September, p. 1426). “Mr. Rodotà has his own approach,” Brachet told Science, “but the member states will decide.” By this Brachet undoubtedly means France and Germany.

  3. ANTHROPOLOGY

    Native Claims Muddy Waters in Fight Over Australian Lake

    1. Elizabeth Finkel
    1. Elizabeth Finkel is a free-lance writer in Melbourne.

    MelbourneIn April 1994, engineers drained the waters of Lake Victoria in New South Wales (NSW) to carry out repairs to a sliding gate that regulates its path to the Murray River. They hoped to refill the lake quickly, but the receding water exposed what appeared to be an ancient burial site extending through a line of sandy islands. A team of archaeologists and Aborigines went to examine the site and rebury the skeletons in accordance with Aboriginal beliefs, but nobody was prepared for the magnitude of the job.

    Colin Pardoe, curator of physical anthropology for the South Australian Museum in Adelaide and the man who assembled the assessment team, estimates that the site contains 10,000 burials, some going back 10,000 years. That makes it “the largest hunter-gatherer cemetery in the world,” says Pardoe. “People freaked out, even archaeologists,” recalls Jeannette Hope, an archaeologist later hired by the Murray Darling Basin Commission to coordinate an environmental impact assessment of the site.

    The discovery delayed plans for refilling the lake until local authorities could figure out what to do. Under the state's National Parks and Wildlife Act of 1974, the existence of Aboriginal relics at the site means that the lake can't be restored unless a “consent to destroy” is obtained from the NSW government. As the austral summer approaches—the second with the lake unfilled—local graziers and irrigation farmers are getting anxious about their vulnerability to a drought. They want the lake refilled. Local Aboriginal groups, one of which has filed a native title claim to the site, are split on what its fate should be. And researchers such as Pardoe (see sidebar) have all but given up hope of studying its rich archaeological record. “Lake Victoria is a can of worms,” says Peter Clark of the Department of Land and Water Conservation.

    Next month, Science has learned, the commission's environmental impact statement will recommend that the lake be refilled. The report will argue that it is possible to retain the lake as a water storage and still protect the sites. The recommendation will go to NSW authorities, who will make the final decision.

    Shaping their deliberations is the rich history of the land occupied by the lake, which sits near the border with South Australia and is part of the floodplain of the Murray River. For the past few thousand years, it has been a seasonal wetland, rising and dropping with each flood cycle. Long a sacred site in Aboriginal mythology, it was also the setting for the Rufus River massacre, a 1841 clash between white cattlemen and the native population. In the 1920s, the flow of the river was altered to provide “drought insurance” for the region.

    Traditional mythology, according to independent anthropologist Sarah Martin, views the lake as the ascension to Nurelli, a Dreamtime creator of the Murray River and Lake Victoria. Burial there was said to assure passageway to the spirits in the sky. That belief, says Martin, who was called in to review the lake's anthropological significance, accounts for the cemetery's great size and its use over thousands of years.

    Pardoe also believes Aboriginal cemeteries in this region served as symbols of “corporate” land use and suggest a settled lifestyle over many generations. According to Aboriginal lore and linguistic and archaeological evidence, the Murray and Darling region encompassing Lake Victoria was occupied by the Maraura-Barkindji (also spelled Paakantji) tribes. In ancient times, says Pardoe, the cemetery would have been “like a neon sign proclaiming [tribal] territory.”

    The Maraura-Barkindji descendants, however, are split on whether to permit the site to disappear again under the lake waters. The majority of the elders are willing to allow the gates to be closed. “We want to do what needs to be done first [to protect the burials], and they can have their water,” says Barkindji elder Roddy Smith. But another group is fighting such a plan. “I don't see any other cemeteries covered by water,” says Ray Lawson, another Barkindji elder. “Would you want the graves of your parents under water?” While Lawson has modified his opposition in recent months, other elders remain steadfastly opposed to the reflooding.

    With tensions escalating, the commission hired Hope in July 1995 to put together a team to gauge the damage from flooding and to assess the cultural importance of the site. Despite a previous report describing the site as a “catastrophe scenario,” Hope was surprised at how much remained intact. The area was extremely rich in artifacts still visible in the original context. “The archaeology was amazing,” she says. “You could visualize how people had lived from the shell middens, fireplaces, and grinding stones.”

    Hope says the 10,000-year stratigraphy preserved in the floodplain at the southern end of the lake is unique in the Murray Darling basin, Australia's only major river system, draining 15% of the continent. Adds Melbourne University geologist Jim Bowler, “Lake Victoria is a modern-day version of Lake Mungo [where stratigraphy with human remains goes back 30,000 years]. It's where prehistory and modern issues come together.”

    Hope concluded that the best way to protect the Aboriginal relics and cemetery, if the lake is to be used for water storage, would be to fill it to a depth of 27 meters, keep it full for as long as possible, and then drop the levels quickly below 24 meters when water is needed. Most of the burials lie at a level of 24 to 26 meters and are buried under at least a meter of sand, she noted, so a 27-meter depth would minimize erosion by waves.

    Hope says that maintenance of the Aboriginal graves should be the top priority if the lake is reflooded, with quick repairs as needed after the water level drops. But with the commission seeking only a 3-year plan, the lake's long-term fate is still being hotly debated. Although draining the lake would aggravate water shortages for three states during droughts, eliminating it might ease the problem of increasing salinity in the region by allowing fresh water from the upper Murray to flush straight through the lake.

    The NSW government will mull over these issues once it receives the commission's report. In the meantime, the Barkindji faction opposed to the flooding has filed a native title claim to the area, which is now owned by the State Water Corporation. A court could determine that the tribe is eligible for compensation if there are plans to alter the use of the contested land. But as with everything else involving Lake Victoria, that issue—whether flooding the lake represents change or the status quo—is also the subject of intense debate.

  4. ANTHROPOLOGY

    Science Squeezed Out of Debate

    1. Elizabeth Finkel

    MelbourneColin Pardoe is considered one of Australia's foremost physical anthropologists, and a pioneer in developing a working relationship with Aboriginal communities. But those achievements have proven to be of little value in the fight over Lake Victoria, a debate in which science has played a decidedly minor role.

    On the face of it, Pardoe, curator of physical anthropology for the South Australian Museum in Adelaide, seemed well-placed to be an active participant in the controversy. His previous research on Aboriginal burials along the Murray River has led him to conclude that such “cemeteries” provide evidence of long-term social structure. He also believes that the characteristic accessory bones, spurs, and holes on the skeletons offer a glimpse into the relationships between past Aboriginal populations. In particular, he says, they suggest that along the densely packed Murray, there was intermarriage among neighboring tribes but little interaction between those separated by greater distances.

    What's more, in the last several years Pardoe has deliberately sought to reconcile Western science with the interests of Aborigines. Together with co-worker Catherine Bennett, he has applied his knowledge to a provenancing project at the museum. He has worked with tribal people to assign unknown remains, long held by the museum, to their correct tribal group based on the variation of skeletal features.

    More recently, Pardoe organized the initial investigation of Lake Victoria and discovered the massive burials exposed when the lake was drained. The discovery, he recalls, seemed to offer him a chance to “finally settle down and do archaeology.” It would be a blend of both scientific and human aspirations—bringing to life a 10,000-year-old story and, in the process, helping Aboriginal descendants to better understand their roots.

    But it was not to be. As the significance of the site emerged, so did its capacity to attract conflict. In addition to disagreements about how such a find should be protected and managed, the site itself constituted a compelling argument for a native title claim. The interests of science took, at best, a back seat to that debate. “We knew there would be politics,” says Pardoe wryly about the forces confronting him and his Barkindji collaborator, Roddy Smith. “But out of all the possibilities, he got done [in] by his mob and I got done [in] by mine.” At one point, Pardoe recalls, his own peers even threatened to prosecute him for trespassing.

    Whether or not the lake is refilled, Pardoe has seen a golden scientific opportunity effectively turn to brass because of the political sensitivity of the site. His appointment at the museum ends in April, and he doesn't expect to stay on. “When problems of archaeology get mixed up with politics, you feel caught in a web of molasses,” he says. “After a while, it becomes impossible to deal with.”

    Still, Pardoe sees a silver lining in the dark clouds hanging over his field. “These are amazing times for Australia's Aboriginals; once we get over this ownership thing, the knowledge is still there. And when that day comes, I'd like to be in on it.”

  5. SCIENTIFIC PUBLISHING

    Libraries Join Forces on Journal Prices

    1. Martin Enserink
    1. Martin Enserink is a writer in Amsterdam.

    AmsterdamSeveral Dutch libraries are banding together to try to hold down future price increases for scientific journals, and they may soon be joined by other European libraries. They are focusing their initial efforts on electronic journals.

    The move was sparked by the imminent merger of the British-Dutch company Reed Elsevier—a leading publisher of scientific, professional, and business information—and one of its main rivals, the Dutch company Wolters Kluwer. The result will be the world's largest publisher of trade and academic journals, with total sales in 1996 of more than $6 billion. About one-sixth of these revenues were generated by highly profitable scientific and medical journals, of which Elsevier publishes some 1200 and Wolters Kluwer more than 300.

    Scientific libraries in the Netherlands were swift to express their fear that the alliance, with an estimated market share of about 20% and a virtual monopoly in some scientific fields, could prompt another round of price increases. Over the past 10 years, scientific information has become ever more costly, with many subscription rates rising by more than 10% a year. “And Elsevier has been the trend setter,” contends Alex Klugkist, chair of the UKB, a consultative body of 15 Dutch scientific libraries.

    Fears about the merger crystallized long-standing concerns among librarians about rising journal prices. Fifteen days after the deal was made public, Dutch librarians announced plans to join forces in their negotiations with publishers. On 28 October, they took a first step by adopting a set of principles that will govern their future negotiations about electronic journals—a territory where they stand to gain most, as pricing policies in this sector of publishing are still taking shape. These “licensing principles” stipulate, for instance, that libraries that subscribe to the printed version of a journal should pay no more than an additional 7.5% to have access to it electronically as well. The libraries also say they will refuse to pay more than 80% of the paper rate to subscribe to the online version alone. They also promise to stand firm on so-called “noncancellation clauses” (an obligation to subscribe to a printed journal for several years).

    Research libraries in eight German states were involved in drawing up these principles and are expected to sign them shortly. Klugkist hopes that many other European libraries will follow suit. Reactions supporting the Dutch initiative have poured in from all over the world, he says. Indeed, the Association of European Research Libraries will discuss collective action at its 1998 meeting, to be held next summer, and the International Federation of Library Associations (IFLA), a worldwide organization headquartered in The Hague, supports the Dutch-German initiative.

    IFLA is also “concerned” about the Wolters Kluwer-Elsevier merger, says Secretary-General Jan Voogt, “because it may further erode the libraries' position.” The organization is consulting lawyers to see whether a formal protest to the European Union's competition directorate would make sense. The Dutch Federation of Tax Consultants has already filed a protest in Brussels—Wolters Kluwer dominates Dutch legal and tax publishing—and European competition commissioner Karel van Miert says he will investigate the merger.

    In a similar vein, the Association of Research Libraries (ARL), an organization of 121 libraries in North America, is considering an appeal to the U.S. Federal Trade Commission. Whatever the outcome, the merger “doesn't bode well” for research libraries, says Mary Case, director of the ARL Office of Scholarly Communication. A study of pricing trends that her organization carried out shows that, compared to 1986, libraries are now spending 124% more to acquire 7% fewer titles.

    Reed Elsevier declined to comment on its pricing policies. A Wolters Kluwer spokesperson told Science the merger would not lead to additional price rises for the company's science publications. But even if their immediate fears are unfounded, the libraries are expected to make the most of the momentum their joint declaration has generated. “We've been talking about a ‘journal crisis’ for years,” says Klugkist. “It looks like it's finally arrived. We're fed up.”

  6. WOMEN'S HEALTH RESEARCH

    A 5-Year Initiative Slowly Takes Shape

    1. Eliot Marshall

    Women's health research is moving “away from the insularity” that characterized it during the early 1990s, says cardiovascular specialist Marianne Legato, who spoke last week at a huge planning session on women's health—part of an effort sponsored by the National Institutes of Health (NIH) to draft a 5-year agenda for the field. Research is “moving out of the pelvis,” as she said—focusing less on anatomy and the reproductive system and more on gender-based differences at the cellular and molecular level. This shift in emphasis, Legato and others argue, could broaden support for women's health research. For example, Legato said, researchers are learning how important hormones are in controlling the development of the brain and other organs—insights they have gained partly by examining how women differ from men. But the results are likely to help men as much as women.

    Legato, who heads a women's health project at Columbia University's College of Physicians and Surgeons in New York, is co-chair of a large task force that's trying to establish priorities for women's health research. The panelists, mostly female leaders of 31 research and advocacy groups, are reviewing presentations given at four meetings sponsored by NIH's Office of Research on Women's Health (ORWH). The results will be passed along to NIH chiefs and members of Congress. Although the report won't be finished for a year, NIH's Donna Dean, Legato's co-chair, said the lessons learned from this advisory process may affect NIH decisions before then. For example, she said NIH may be ready to fund an initiative on autoimmune disorders inspired in part by pressure to act on lupus, which is far more likely to strike women than men. And one institute is planning to fund new obstetrics and gynecology research centers.

    Last week's review was the final session in a yearlong series of meetings held around the country by ORWH director Vivian Pinn. At a press conference on 19 November, Pinn said the aim is to examine what's been accomplished in the 7 years since ORWH was created and to consider “priorities and scientific directives … as we move toward the year 2000.” The gathering also served to raise the visibility of Pinn's office: It drew one Cabinet member—Health and Human Services Secretary Donna Shalala—and three members of Congress.

    Writing up the recommendations from this exercise won't be easy. A draft list of top priorities discussed at last week's meeting was so long the items were categorized under 25 major headings. The job of sifting wheat from chaff now falls to Legato and Dean.

  7. JAPAN

    Pending Reform Plan Lacks Detail

    1. Dennis Normile

    TokyoA blue-ribbon advisory panel to Japan's government is expected to release a report next week that could lead to the merger of the country's two major science-related ministries and the granting of greater independence to its extensive network of national labs. Those changes are among a host of recommendations for streamlining the government, aimed at fulfilling a 1996 campaign promise by Prime Minister Ryutaro Hashimoto. But even before the final wording is ironed out, the plan has generated heated political debate.

    The report is the result of a yearlong effort by the Administrative Reform Council to draw up a more efficient administrative system for the 21st century. The once sterling reputation of the Japanese bureaucracy has been severely tarnished in recent years by bribery scandals, cover-ups, and general charges of mismanagement, and the reform council was formed to shrink its size and rein in its power. Akito Arima, a physicist who is president of the Institute of Physical and Chemical Research (RIKEN) based near Tokyo, is the sole scientist on the 15-member panel, which Hashimoto chairs.

    Although the calls for reform were not aimed at science-related agencies, the council's brief included the Science and Technology Agency (STA), which oversees many of the nation's big-science projects, and the Ministry of Education, Science, Sports, and Culture (Monbusho), which funds most academic research. The council is recommending that the two be merged into a Ministry of Science, Technology, and Education, as proposed in an interim report issued this summer (Science, 29 August, p. 1198). It also suggests turning some government service operations, possibly including national research institutes, into independent agencies. The goal is to make them more efficient and better able to meet well-defined goals.

    Most scientists are hesitant to endorse or oppose either change until they see the details. “There has really been very little public discussion of the merits and demerits of merging STA and Monbusho,” says Keiichi Kodaira, director-general of the National Astronomical Observatory in Tokyo, which falls under Monbusho's jurisdiction. Granting national labs more independence, he says, could free them from cumbersome government-wide regulations governing employment and accounting practices. But how much leeway to give them has yet to be worked out. The report is also silent on how the independent research institutes would be funded.

    One reason for the lack of detail may be the amount of time the council devoted to proposed reforms of the powerful ministries of Finance and of Posts and Telecommunications. Last week, the council appeared to soften several interim proposals affecting the two ministries, causing pundits here to lambaste the council for lacking the political will to curb the power of the bureaucracy.

    In the meantime, some scientists feel left out in the cold. “The high public and political interest [in other areas] is understandable,” Kodaira says. But he worries that the reforms have been pursued with little regard for the long-term implications for research. “It's been a discussion without a vision [for science],” he says.

    The reform council's report is expected to be issued on 5 December after its final wording is crafted by the council's secretariat, made up of bureaucrats seconded from various ministries. The reform issue will then be taken up by the three-party coalition government that Hashimoto leads. The next step would be a proposal for reform to the Diet (legislature) that could set the stage for introducing a new, slimmer government in 2001.

  8. FUSION

    Brighter Omens for Giant Reactor?

    1. James Glanz

    PittsburghTurbulence in plasmas, or ionized gases, was once an obscure topic studied far from the public eye. That was before a debate erupted among researchers over whether turbulence would cause heat to leak from a prototype fusion reactor—the projected $10 billion International Thermonuclear Experimental Reactor (ITER)—so fast that it would fall short of its design goals. That debate, first reported inScience (6 December 1996, p. 1600), remains unresolved and highly charged. And it received fresh fuel at a tense session here last week, during a meeting of the American Physical Society's division of plasma physics.

    A new set of calculations presented at the session suggest that fusion reactors like ITER would leak heat more slowly than predicted by the model that set off the debate last year. That model, developed by researchers at the Institute for Fusion Studies (IFS) of the University of Texas, Austin, and the Princeton Plasma Physics Laboratory (PPPL), treats the plasma as a continuous fluid. The new work takes a different approach: It calculates the trajectories of millions of individual particles in the plasma. This “gyrokinetic” approach points to a much slower turbulent heat loss. “The [IFS-PPPL] predictions are overly pessimistic,” says Scott Parker, the gyrokinetic modeler at the University of Colorado, Boulder, who organized the session.

    “Everyone asks about the implications for ITER,” adds Parker. “That's the $10 billion question.” Neither he nor anyone else is ready to say the results put ITER in the clear. Despite months of detailed comparisons between the two sets of computer codes, Parker and others have been unable to pinpoint why the predictions differ under some conditions. “You can't make the case that you've got a rock-solid theory that's going to predict the performance of ITER,” says James Drake, a plasma theorist at the University of Maryland, College Park, who is unaffiliated with either camp. Says PPPL's Gregory Hammett, who spoke at the session: “Our main message last year was that ITER's fusion-power output is highly uncertain.” For now that message remains unchanged, he says.

    ITER would be by far the largest ever tokamak, a doughnut-shaped device threaded with magnetic field lines that cage hot plasma. If that cage could confine plasma ions at high enough energies for long enough, the resulting fusion reactions might cause the plasma to ignite in a self- sustaining thermonuclear burn. The IFS-PPPL model predicts—although with wide error bars—that the cage will not hold: Turbulence within the ITER plasma will kick enough hot particles through the cage to keep the device from approaching ignition.

    To limit the amount of computation required, parts of the model approximate the plasma as a smooth fluid instead of trying to follow each particle as it races through the plasma. The computational savings allow team members William Dorland and Michael Kotschenreuther of IFS and Hammett and Michael Beer of PPPL to check the heat transport over a wide range of plasma temperatures, pressures, and other conditions, and compare the results to those obtained by experiments. But the approach neglects some effects, such as the trapping of individual particles in the troughs of turbulent waves, which could affect the transport.

    In an attempt to improve on the fluid approximation, researchers such as Andris Dimits of Lawrence Livermore National Laboratory in California and his co-workers, Parker, and others have now built simulations that follow millions of particles directly. From a physics standpoint, says ITER physicist Marshall Rosenbluth, that approach promises “a more fundamental description” of a real plasma. But Parker notes that the large amounts of computer time required mean that these codes “haven't been compared with experiments the way the IFS-PPPL model has,” nor have they modeled the heat transport over as wide a range of plasma temperature and pressure profiles.

    The session highlighted a handful of comparisons between the Dimits group's gyrokinetic model and the IFS-PPPL results. There is “perfect agreement” in some comparisons, says Dimits. But other experimentally relevant cases, he says, show that heat “conductivity” is lower in the kinetic simulations by as much as a factor of 3. Combine the best of those numbers with optimistic assumptions about the temperature at the edge of the plasma, says Hammett, and the plasma's center could be hot enough for ITER's output to push into the range that its designers hope for.

    But why the two sets of models differ is a mystery. “There's a clear difference, and nobody knows why,” says Glenn Bateman of Lehigh University in Bethlehem, Pennsylvania. Dorland says the possibilities include bugs or inadequate numerical resolution in the various codes, something in the detailed physics of wave-particle interactions, or even mundane issues such as the different coordinate systems used by the different groups.

    The continuing uncertainty about the outlook for ITER led to jousting at the session between proponents of the project and researchers seen as critical of its prospects. But what's clear, says Drake, is that the past year of jockeying between models has rejuvenated the theory of turbulent heat transport. Converging on a theory everyone accepts is no longer out of the question, he says: “I would not phrase this as a right-wrong issue. We're making tremendous progress; it's very exciting.”

  9. CELL BIOLOGY

    Multiple Clocks Keep Time in Fruit Fly Tissues

    1. Elizabeth Pennisi

    Anyone who has ever flown across two or more time zones doesn't have to be convinced of the importance of the body's internal rhythms. They are all too apparent—say when the East Coaster visiting California pops awake at 4 a.m. and then has to struggle to keep from falling asleep after dinner. For 25 years, neuroscientists have focused on the brain as the master timekeeper for biological rhythms, controlling everything from normal fluctuations in body temperature to midafternoon slumps. But that view is about to change, at least for fruit flies and perhaps for higher species as well.

    Lighting up.

    The luminescence (false-colored green) indicates activity of the clock gene per in the proboscis and antennae of the fruit fly.

    J. D. PLAUTZ AND S. KAY

    On page 1632, a multidisciplinary team led by geneticist Steve Kay of The Scripps Research Institute in La Jolla, California, reports new evidence indicating that fruit flies have independent clocks throughout their bodies. By harnessing recently developed techniques for imaging proteins in living cells, Kay and his colleagues tracked the production of a timekeeping protein, called PER. Previous work had shown that per, the gene that makes the protein, cycles on and off in the fruit fly brain to establish the body's daily rhythms (Science, 22 March 1996, p. 1671). Kay and his colleagues now find that this cycling is widespread in fruit fly tissues.

    Clocks galore.

    The blue in this false-color image points to the existence of independent clocks throughout the fruit fly body.

    J. D. PLAUTZ AND S. KAY

    They saw PER appear, disappear, and reappear over and over—in the legs, wings, thorax, head, and abdomen of the insect. “This paper shows clocks all over the place, all at once, in a very graphic fashion,” marvels Martin Zatz, a physiologist at the National Institute of Mental Health. “Wherever they look, they find clocks.”

    Each of these clocks can be set independently, by light, and they keep ticking on their own schedule even when they are isolated from the brain, indicating that they don't need input from a master clock to keep time. Other recent work suggests that mammals, too, have multiple clocks. “It is conceivable that individual cells undergo daily cycles of activity and rest just like whole organisms do,” suggests Jadwiga Giebultowicz, an insect physiologist at Oregon State University in Corvallis.

    If that proves to be the case, the implications are “quite provocative,” says Joseph Takahashi, a clock biologist at Northwestern University in Evanston, Illinois. No one questions a role for the brain's clock in overseeing overall rhythms, such as body temperature or behaviors like waking up which involve coordinating several muscle groups and hormonal changes. But these apparently independent clocks may help various parts of the body tailor their protein production to suit the needs of the hour, Takahashi says. Eyes, for example, may produce different mixtures of photoreceptor proteins at different times of day to make adjustments for night vision, while muscles might rev up their metabolism in anticipation of daytime activities.

    The idea of the brain's overriding importance in controlling daily rhythms dates back to 1972 experiments on the effects of damaging or destroying a brain structure called the suprachiasmatic nucleus. Doing so changes or eliminates daily cycles in rats, including the rise and fall of the adrenal hormone corticosterone and daily drinking behavior and locomotor activity. While the fruit fly is not advanced enough to have a suprachiasmatic nucleus, its brain also seemed to be required for the insects to keep their daily schedules. Developing fruit flies with damaged brains, for example, emerged from their pupal cases at random times in the day instead of in the morning, as they normally do, and were no longer active primarily in the morning.

    As researchers began discovering the molecular components of this clock, the focus remained on the brain. By tracking down the genes at fault in mutant flies with odd daily rhythms, geneticists discovered clock components including per. This gene's expression in the brain fluctuates in a predictable pattern over 24 hours. And when a per equivalent turned up 2 months ago in humans and mice, researchers found its expression also followed a daily cycle in the suprachiasmatic nucleus (Science, 19 September, p. 1762).

    But neurobiologist Jeffrey Hall of Brandeis University in Waltham, Massachusetts, and others had found PER in various parts of the fruit fly besides the brain, implying that molecular clocks might not be confined to the brain. To follow up on those hints, they needed a technique that could monitor gene expression in a single living animal over time so they could be sure changes in gene expression were not simply due to individual variation. And that's where a technique Kay had developed 5 years ago for monitoring gene expression in living cells came in.

    The technique involves fusing the DNA that regulates the expression of whatever gene a researcher wants to study to the gene for luciferase, the enzyme that generates a firefly's light. Kay introduced one such fused gene into plants, then sprayed them with luciferin, the firefly chemical that luminesces when acted upon by luciferase. By simply watching for the glow, he could tell when the regulatory sequence had turned on the target gene.

    When Hall learned of that result in 1992, he persuaded Kay to collaborate with his team in trying the same approach for studying per expression in fruit fly tissues. In one set of experiments, Kay's graduate student Jeffrey Plautz engineered fruit flies with the luciferase gene fused to the DNA that triggers per expression. In these fruit flies, Plautz could watch the expression of per's stand-in, the luciferase gene, change over time within the fly body, although the signal was too weak to see exactly where the expression was taking place.

    To get around this, Maki Kaneko from Hall's group adapted the technique to use a more vivid optical signal, from the green fluorescent protein (GFP) of jellyfish. She did this by breeding two transgenic strains, one with the GFP gene linked to a yeast promoter and one with the per promoter linked to a yeast gene that would trigger expression of the hybrid GFP gene. By watching for the vivid glow of GFP in the crossbred flies, the researchers could see which tissues, and sometimes even what specific cells, make the PER protein.

    They first looked at whole fruit flies, confirming in the GFP insects that per is indeed active all over. The luciferase transgenic fly indicated that per also cycles on and off just as it does in the brain. To determine whether the individual tissue clocks are controlled by the brain clock, they cut up the transgenic flies and incubated the heads, thoraxes, and abdomens separately in culture dishes. They found that the tissue per genes could cycle even in the absence of a brain.

    When exposed to alternating periods of 12 hours of light and 12 hours of darkness, the gene turned on and off in the isolated tissues every 24 hours. And as with brain clocks, the cycling continued when the tissues were kept in complete darkness, although they did not keep time as faithfully as tissues experiencing both light and darkness. Turning the lights on, however, reset these clocks in the various body parts, even those lacking the head. “You don't have to go through the known eyes to get light to this tissue,” Hall points out.

    What's more, the researchers could see clock activity not just in whole body sections, but in smaller organs such as the antennae and proboscis, or feeding tube. Indeed, the technique enabled them to identify specific chemosensory cells with periodic per expression, which suggests that even individual cells can keep time on their own. This many clocks “was a real surprise,” Kay notes.

    It's not completely unprecedented, however. In 1989, for example, Oregon's Giebultowicz had found a clock located in the testis of the gypsy moth that governs daily, predictable fluctuations in the release of sperm. And just last April, her team came across another tissue clock. The fruit fly's malpighian tubules, which act like a kidney, have a daily rhythm, evidenced by cyclical expression of per and another clock gene called tim. This gene activity pattern occurs independently of the brain and can be reset by light, she reported. Also that month, another research team led by Katherine Siwicki of Swarthmore College in Pennsylvania showed that the fruit fly's ring gland, which secretes hormones, also operates on its own time.

    But by and large, Giebultowicz says, “those [clocks] were considered exceptions to the rule” that the brain clock was primary. Now, the Kay team's experiments really drive home how widespread clocks are in the body. “[The technique] is spectacular,” says Michael Menaker, a neurobiologist at the University of Virginia, Charlottesville.

    Much less is known about clock operation in mammals, because the genes involved are only now being discovered. But already there are hints that higher organisms may also have multiple clocks. The mouse per gene, for example, is active in many tissues, including the heart, lung, liver, and kidney, and is particularly active in the testis and skeletal muscle. And another mammalian timekeeper gene called CLOCK, identified by the Takahashi group, is also expressed in lots of tissues. “This is making us think that there are clocks in other tissues,” says Takahashi. To see if that is in fact the case, Kay is now using his luciferase technique in mouse tissue to test whether the expression of these mammalian genes outside the brain follows a daily schedule.

    To understand the tissue clocks, however, chronobiologists will need to figure out how they sense light. For the brain clock, this job is performed by the retina, although not by the light-sensitive cells responsible for vision. The optic nerve then transmits the information to the brain. But cells outside the retina lack the photosensitive pigments found in the eye. Instead, there are hints that these tissues may use recently discovered proteins that are sensitive to blue light.

    Some of these help repair DNA damaged by ultraviolet light, but both plants and mammals have blue light-sensitive proteins that have nothing to do with DNA repair. Aziz Sancar, a biochemist at the University of North Carolina, Chapel Hill, has found two such proteins in humans, both of which are located in the same tissues as the clock proteins. “We think there's an 80% probability that this will turn out to be a blue-light photoreceptor for activating circadian clocks,” says Sancar.

    He and Japanese researchers are making mice that lack these proteins to test out this prediction. They are convinced light can reach deep into the body where these sensors reside. “We're talking about a different light perception and a different time scale [than in vision],” Giebultowicz agrees. Rather than relying solely on a master clock in the brain to coordinate all body rhythms, for these many other clocks, Kay proposes, “the true master switch is just sunlight.”

  10. POLAR RESEARCH

    Spacecraft Offers Details of Antarctica

    1. Andrew Lawler

    A new Canadian radar satellite is giving polar researchers the first highly detailed map of Antarctica and its ice sheet, revealing unexpected ice flows and a heavily textured surface in areas that were thought to be largely featureless. Researchers say the data offer clues to the topography of the continent hidden under the ice. Comparisons with earlier images could also trace the retreat of ice shelves and glaciers, a possible sign of global warming.

    Antarctica's expanse of ice shelves, mountains, and ice-covered plains is largely unexplored. But because the region contains nearly three-quarters of Earth's fresh water, changes there can have a major influence on world sea levels and climate. This fall, the Radarsat spacecraft, which has been mapping the Earth's surface for 2 years, turned its attention to Antarctica. Over 18 days as it crisscrossed the continent, Radarsat gathered 8000 separate images with its synthetic aperture radar, which peers through clouds and darkness to pick up detailed surface relief. “It's been a resounding success,” says Robert Thomas, chief of NASA's polar research program, which is overseeing the work.

    The initial results were a surprise, adds Ken Jezek, a geologist at Ohio State University in Columbus, who has a $2.8 million, 3-year NASA grant to conduct the study. “We expected to see a flat and featureless Antarctic ice sheet—particularly in the east—but we're seeing great detail and exotic features.” For example, oddly shaped flows of ice that extend for hundreds of kilometers upstream of the massive Recovery Glacier hint at the complex shape of the bedrock below. And by contrasting the data with those obtained by U.S. spy satellites in the 1960s, he says, scientists can also study the retreat of the ice shelves that fringe the coast.

    The Canadian government paid for the construction of Radarsat, and NASA launched it in November 1995 in exchange for a 15% share of the satellite's use. A private company—Radarsat International Inc.—sells the data to users ranging from oil and gas companies to disaster relief organizations. As a result, data gathered during NASA's projects—such as the Antarctica images—are supplied to researchers who win peer-reviewed grants, but further dissemination is restricted because of the data's potential commercial value. Jezek says it will take more than a year to process the Antarctica data fully so all the images mesh. A follow-up mission is planned before the century is out.

  11. EVOLUTION

    Sex Frees Viruses From Genetic 'Ratchet'

    1. Virginia Morell

    Arnhem, The Netherlands—It's probably the only question that the celebrated sexologists Masters and Johnson didn't ask: How did sex originate? Evolutionary biologists, however, have puzzled for much of this century over why so much of life has evolved the ability to shuffle genetic material between individuals—the essence of sexual reproduction. “It must confer some benefit,” Lin Chao, an evolutionary biologist at the University of Maryland, College Park, said at a meeting of the European Society for Evolutionary Biology here in August. He then went on to report some of the first experimental evidence supporting one explanation, proposed 3 decades ago: that sex enables a population to free itself of harmful genetic mutations.

    Even viruses do it.

    Viruses from two strains infecting the same cell can recombine whole chromosomes (right) or swap chromosome segments (left) in their offspring.

    ILLUSTRATION: LIZ CARROLL SOURCE: LIN CHAO

    Chao gathered his evidence in one of the simplest of all sexual organisms, an RNA virus whose rapid mutations and short generation time put evolution on fast forward. “He's developed a clever experimental system to test a classic question in evolution,” says Peg Riley, an evolutionary biologist at Yale University. “And he's got strong results” that support the hypothesis.

    In the early 1960s, evolutionary theorist Hermann J. Muller argued that small, asexual populations would necessarily decline in fitness (or reproductive success) over time if their mutation rate was high, because they would accumulate harmful mutations. Muller proposed that this process would work like a ratchet, with each new mutation irreversibly eroding the population's fitness. Sex could provide an escape from the ratchet, he said, because recombination lets an organism reconstruct a mutation-free genome from two genomes that contain different mutations.

    But devising a method to test the idea requires more than your garden-variety lab animal. Besides short generations and rapid mutations, the organism needs to be able to reproduce sexually as well as asexually. “You can't see the advantage of sex, unless you can withdraw that advantage,” says Chao. Certain RNA viruses, he notes, fit the bill on all counts.

    Chao chose to work with the ϕ6 virus, which infects bacteria. The ϕ6 genome is made up of three RNA segments, and virus “sex” consists simply of reshuffling these segments with those of another virus that has infected the same cell. Although segment swapping differs from the sexual reproduction technique of eukaryotes, it still produces a hybrid progeny and “so is another form of sex,” Chao says.

    But there was no joy of segmented sex for Chao's ϕ6 viruses. Instead, by some careful chaperoning, he forced them to reproduce asexually. He began by infecting a bacterial host with a single virus. As soon as this virus began to reproduce, he randomly selected just one of its progeny and used it to infect a new bacterial cell. The virus never had a chance to reshuffle its segments with those of another particle that had infected the same cell. “We pushed them through 40 of these bottlenecks,” says Chao.

    At this stage, Chao suspected that Muller's ratchet probably had a firm lock on the virus, impairing its reproductive fitness—a hunch he confirmed by placing one particle of the bottleneck virus and one of the original virus in fresh bacterial cultures for a day to see which reproduced more abundantly. In 20 such reproductive-competition bouts, the original strain of the virus always won. Next, Chao allowed different reproductively enfeebled viral populations to co-infect the same cells and reproduce sexually with each other. In about 30 generations, they had regained much of their reproductive fitness.

    But was their renewed fitness actually due to sex, or simply the result of new mutations that made up for the deleterious ones? To answer this question, Chao staged a fresh series of experiments. In one, he crossed reproductively handicapped viruses with themselves to create a large population of “selfed” viruses. He then allowed the viruses to evolve freely over 30 generations. Because this population was not passing through bottlenecks, beneficial mutations would be likely to accumulate. But because the particles had nearly identical genomes, sex wouldn't offer any advantage.

    The selfed virus increased its fitness by 21% compared to its original, reproductively deficient ancestor. “That increase was solely due to the virus's high mutation rate,” says Chao. But when he added the benefits of sex by allowing the selfed virus to interbreed with other populations, the resulting population gained another 9% in fitness.

    “We knew that the virus could recover its fitness from mutations alone,” says Chao, “and people used to think that this effect would be so great, it would swamp out any advantage of sex.” But that was not the case. “[The study] shows that sex is advantageous,” he says. Riley adds that in Chao's experiment “sex does affect Muller's ratchet; it provides an escape”—which is just what most sex researchers have always said.

  12. EVOLUTION

    Viruses Scout Evolution's Path

    1. Virginia Morell

    Arnhem, The NetherlandsSex can lead to many things—even the merging of two seemingly incompatible evolutionary theories. So says Lin Chao of the University of Maryland, College Park, who realized that the fast-evolving viruses he uses to test theories about the evolution of sex (see previous story) could help settle another debate. At a meeting of the European Society for Evolutionary Biology here in August, Chao described how the viruses pointed to a possible resolution of a decades-old dispute about the trajectory of evolution.

    Pathfinders.

    Christina Burch and Lin Chao traced the course of evolution in viruses that infect these bacterial cultures.

    SAM KITTNER

    R. A. Fisher of Cambridge University had argued in the 1930s that evolution is like a staircase, on which organisms evolve through a series of small genetic steps, each one leading to a higher level of fitness. They continue to climb the same staircase, refining existing adaptations, unless a dramatic shift in the environment forces them to begin scaling a different set of stairs. In contrast, Sewall Wright, working at about the same time at the University of Chicago, imagined that genetic changes, as well as environmental ones, could derail the evolutionary process. He pictured evolution as taking place on a landscape of numerous peaks and valleys. In his eyes, harmful mutations can displace an organism from a peak into a valley. In overcoming such mutations, organisms may begin climbing a new peak, setting them on a different evolutionary course.

    Chao's virus cultures suggested that both metaphors may be valid. He and his graduate student Christina Burch had originally set out to test Fisher's model of adaptive evolution, which holds that large mutations that dramatically increase fitness are likely to be rare because such mutations tend to have large, deleterious side effects. “Fisher's model is such a pretty idea,” says Chao, “because it makes a very strong, straightforward prediction.” Yet despite its elegance, Chao notes, “good data to support it don't exist.”

    Chao and Burch thought they might find supportive data by experimenting with RNA viruses because of their breakneck evolution. They multiply 100-fold every hour or so and pick up many mutations along the way. To see if viral evolution matches Fisher's model, the researchers studied a population whose members had all suffered from a deleterious mutation, which cut the number of progeny they produced. “We wanted to see how—either through large or small steps—it would regain its fitness via natural selection,” explains Chao.

    The researchers used populations of the severely mutated virus ranging in size from 10 to 10,000 particles. Each population was allowed to grow freely on a bacterial host. At the end of each day, Chao and Burch staged experiments comparing the test viruses with the original, unmutated strain to see how quickly the different populations were regaining their fitness.

    In populations below 1000 particles, “fitness increased in multiple steps,” Chao says, “which surprised and delighted us.” In populations of more than 1000 particles, the virus came roaring back in one large step, presumably because large compensatory mutations were more common in the larger populations. But Chao argues that the combined results support Fisher, “because his model predicted that compensatory mutations of large effect would be rare, and that's exactly what we found. They don't occur except in very large populations.”

    Burch and Chao's experiment is “the first really serious empirical test of Fisher's model,” says Bruce Levin, a population geneticist at Emory University in Atlanta. He adds that it shows “the power of using microbial systems to test general evolutionary hypotheses.” But even if Fisher was right about the pace of evolutionary change, Chao adds, the results also support Wright's view that evolutionary shifts can occur without major environmental change.

    The populations regaining their fitness via small compensatory mutations necessarily ended up at new adaptive peaks, says Chao, which represent different ways of attaining the same fitness. “The only way to go back to the same peak you started on” is via a “back mutation” that reinstates the gene in its original form—which should occur only in a single, big step, he explains. In contrast, “a compensatory mutation implies that you're headed toward a new peak.” He adds, “At least in this one case, it seems that Fisher's model fits with Wright's view of an evolutionary landscape.”

    “It's absolutely intriguing,” says Hope Hollocher, an evolutionary biologist at Princeton University. “Chao has opened the door toward merging these two viewpoints.” She notes, however, that his experiments need some fine-tuning before biologists will be convinced that Fisher and Wright aren't always at odds.

  13. DEVELOPMENTAL BIOLOGY

    New Developmental Clock Discovered

    1. Elizabeth Pennisi

    Biological clocks are turning up all over, and in the most unexpected places (see p. 1560). But they all typically keep to a 24-hour schedule, which is logical because it helps keep organisms in tune with the normal day length. But now, a team of French and British scientists has come across a new kind of biological clock, one that not only has a much shorter cycle—only 90 minutes—but also appears to be driven by a different kind of mechanism.

    In today's issue of Cell, Olivier Pourquié, a developmental biologist at the Developmental Biology Institute of the University of Marseille in France, and his colleagues report evidence indicating that such a clock paces the development of the somites, blocks of tissue that form in regular arrays along the spinal cord of vertebrate embryos and give rise to vertebrae and muscles. The researchers found that in the developing chick embryo, a gene called chairy undergoes repeated 90-minute cycles of activity, its expression narrowing each time to a thin band that defines the rear edge of a new somite. These cycles seem to specify the orderly delineation of somites in the growing embryo.

    Now the Pourquié team and others are eager to know what makes this clock tick. “It's the first time that very clearly there is a clock associated with a developmental process,” says clock biologist Paolo Sassone-Corsi of the University of Strasbourg in France.

    The finding also has evolutionary consequences, because chairy is the chicken equivalent of a fruit fly gene called hairy (chairy is short for chick hairy), which helps drive formation of the segmented insect body plan. Developmental biologists have long debated whether the segmentlike somites of higher organisms and insect segments arose independently or had a common origin. Until now, they have failed to find common genes involved in forming these structures, but the new chairy results provide just such a link. “It's cool stuff,” says Eddy De Robertis, a developmental biologist at the University of California, Los Angeles, who has proposed a common origin for insect and somite segmentation (Science, 4 July, p. 34).

    David Ish-Horowicz's team at the Imperial Cancer Research Fund Laboratory in London originally cloned hairy more than a decade ago and showed that it is expressed in a series of stripes that help define the segments of the developing fruit fly embryo. He and Domingos Henrique in his lab then used hairy's sequence to track down chairy, a comparable gene in the chicken. But neither they nor Pourquié, a collaborator on another project, could make sense of chairy's seemingly variable expression pattern in the chick embryo.

    To try to sort out the problem, Pourquié and his student Isabel Palmeirim divided chick embryos, fixing one half while maintaining the other in culture. When they then compared the gene's expression in the two halves at different times, the link to somite formation emerged. As chick embryos grow, cells are added behind the head to form a long, broad “tail.” Once this tail reaches a certain size, somites begin to form one at a time, starting with the one closest to the head and working tailward. Each somite—there are 50 of these visible blocks of tissue in all—takes about 90 minutes to appear.

    When the Pourquié team monitored chairy expression as the somites formed, they found that the gene was pacing the process. It first becomes active across the rear 70% of the presomatic tissue, starting from the tip of the tail. Over the next 30 to 40 minutes, that band of expression narrows and shifts forward toward the head, where the next somite will develop. Finally, after 90 minutes, the expression band becomes a thin stripe marking the rear edge of the new somite. At the same time this stripe appears, the gene comes back on again over the same broad region where it was initially expressed and begins the cycle anew until all 50 somites develop. “[Expression] spreads along the tissue in a very coordinated fashion,” Pourquié says. This repeated, coordinated expression, he suggests, dictates to cells when it is their turn to form a somite. But he has yet to determine what coordinates the gene expression.

    It's not controlled by signals from elsewhere in the chick embryo, because chairy cycled on and off even after the tissue where it was expressed was teased out of the embryo and grown separately. And it's not a clock like those found in other organisms, because those clocks require protein synthesis. Gene expression still followed this repeating pattern even when protein synthesis was blocked, his group reports.

    But these results make the find all the more intriguing, say other researchers. They suggest that this developmental clock keeps time using a new clock type of mechanism, one that Pourquié and his colleagues are working hard to pin down. Sassone-Corsi also predicts that this new developmental clock will inspire other researchers to look for other types of clocks and timing mechanisms, and that, he adds, “is exciting.”

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