# News this Week

Science  23 Oct 2009:
Vol. 326, Issue 5952, pp. 506
1. Conservation Biology

# Research Wolves of Yellowstone Killed in Hunt

1. Virginia Morell

On 3 October, a few weeks after Montana opened its first legal wolf-hunting season in decades, a hunter killed a female wolf in the Absaroka-Beartooth Wilderness, less than a mile from the border of Yellowstone National Park. She wasn't the first Northern Rocky Mountain gray wolf to be legally hunted since wolves were removed from the federal endangered species list last May. But she was the alpha female of Yellowstone Park's Cottonwood Pack and wore a large radio collar identifying her as wolf 527F. Her behavior, travels, life history, and genealogy had been studied in detail by scientists for 5 of her 7 years. Her death, and that of five other pack members also shot outside Yellowstone, including another radio-collared female, have irrevocably changed what had been a unique long-term study, the researchers say.

“We were studying one of the very few unexploited wolf populations in North America,” where packs had lived and died naturally, says wildlife biologist Douglas Smith, leader of Yellowstone's wolf project, which has tracked the wolves since their reintroduction in 1995. “We can no longer make that claim.”

The park's wolf project, partially funded by a $480,000, 5-year National Science Foundation grant, isn't the only scientific study adversely affected. The death of the wolves and loss of the pack are also a blow to a host of studies, from wolf behavior to elk management and ecology, say other scientists, several of whom have repeatedly asked Montana's Fish, Wildlife and Parks (FWP) department to establish a no-wolf-hunting zone around the park (Science, 15 February 2008, p. 890). “Yellowstone is one of the best examples in the world of what happens naturally to an ecosystem when an apex predator is returned,” says ecologist William Ripple of Oregon State University, Corvallis, who has shown that wolves are helping to rebalance the park's ecosystem (Science, 27 July 2007, p. 438). “If the park wolves are being shot at, they're bound to change their behavior.” A possible buffer zone and other suggestions will be considered as they review this season's hunt, say FWP officials, who add that the hunt that killed 527F had not worked out as expected. In only 4 weeks, hunters had killed nine wolves in the Absaroka-Beartooth Wilderness, including 527F, nearly filling the quota of 12 wolves for this area's early season hunt. As a result, the agency last week closed the wilderness to wolf hunting for the remainder of the season, which ends when snow keeps hunters out. “We didn't think that wolves would be that vulnerable in the backcountry, so the level of harvest there has been a bit of a surprise,” says Carolyn Sime, FWP's wolf program coordinator in Helena, who added that the hunt was designed to target wolves that kill livestock, not wilderness or park wolves that have never caused problems in that area. However, many hunting camps are set up in the Absaroka-Beartooth Wilderness to take advantage of elk migrating out of Yellowstone, conservationists point out. Also, park wolves are naïve. “Every person the park wolves encountered was benign until now,” says Smith. Inside the park, wolves are regarded as study animals and tourist magnets, pulling in a minimum of$35 million a year in tourist dollars, according to a 2006 University of Montana study. But as soon as a wolf crosses into Montana, it falls under state law, which regards the canids as “a species in need of management”—another big game animal that can be hunted like the deer, elk, bear, and mountain lion that also travel in and out of the park. Five of Yellowstone's remaining 12 packs have territories that stray outside park borders.

Some wildlife officials point out that the Cottonwood Pack may not be completely gone. The killing of most of its members has not greatly harmed Yellowstone's wolves or scientists' research, they argue, because there are more than 100 wolves left in the park and one wolf pack is very like another. “Biologically, [the loss] has no impact, since wolf packs turn over all the time,” says Edward Bangs, wolf recovery coordinator for the U.S. Fish and Wildlife Service in Helena. “It doesn't make any difference to wolf conservation or wolf research, although it will cost Doug [Smith] more money to collar another wolf.”

But from Smith's perspective the Cottonwood Pack is gone, and he will need to collar two more wolves—a dangerous, time-consuming task, costing $1500 per wolf—to successfully track whatever pack moves into the Cottonwood's former territory, which was 95% inside park boundaries. In addition, much of the data gathered on 527F and her pack are now worthless because the wolves met an unnatural end and no longer fit the project's study criteria, he says. The project is now adding a new category to many of its 85 databases: harvested wolf. A secretive wolf, whose territory this year was so remote that researchers seldom saw her, 527F was raising her third litter. (The fate of her five 5-month-old pups is not known.) At the advanced age of 7, she was a key animal in many studies, including some on how long wolves live, their maximum body size, and female wolves' lifetime reproductive success. These are some of the many unknowns of wolf biology that “can't be studied outside Yellowstone because people curtail wolves' maximum life spans,” explains Smith. Smith collars the wolves, but many scientists independent of the wolf project have been gathering data on the radio-collared wolves. “Any time radio-collared animals are lost, it's a huge setback for our research, since it's the best tool for tracking their movements,” says Daniel McNulty, an ecologist at Michigan Technical University in Houghton, who has been studying wolf-prey dynamics in Yellowstone. He worries that annual hunting of Yellowstone's wolves will eventually affect their social dynamics and age structure, “skewing it toward the younger classes, something that has been demonstrated in every game population” worldwide. That, in turn, could potentially be bad news for the park's elk, because McNulty's research has shown that younger wolves kill more elk. Evolutionary geneticist Robert Wayne of the University of California, Los Angeles, adds that an annual hunt, as is now planned for the Absaroka-Beartooth Wilderness, runs the risk of turning the area into “a predator sink, drawing wolves out of Yellowstone,” as young, dispersing animals search for unoccupied territories. “This shouldn't have happened,” he says. “Yellowstone's wolves should have absolute protection.” But they don't, and Montana's FWP has a quota of three additional wolves in other areas adjacent to Yellowstone. Montana's statewide wolf-hunting season opens on 25 October. 2. Amphibian Decline # Life and Death Play Out on the Skins of Frogs 1. Elizabeth Pennisi For herpetologists, the global decline of amphibians has been agonizing. For Jamie Voyles, the most disturbing episode was witnessing the death of diseased frogs at the Omar Torrijos Herrara National Park in the Republic of Panama in 2004. “The subsequent silence left a long-lasting impression on me,” recalls Voyles, a graduate student in disease ecology at James Cook University, Townsville, in Australia. At the time, few clues existed about how the culprit—a fungal infection—could be so lethal. “Understanding how [the fungus] kills frogs was one of the biggest mysteries about the disease,” she recalls. Now on page 582, Voyles and her colleagues go a long way toward solving that mystery. They find that the fungus, Batrachochytrium dendrobatidis, causes such severe electrolyte imbalances that the frog's heart stops. “It fills a big knowledge gap about one of the most devastating [amphibian] diseases we've ever encountered,” says Brian Gratwicke of the Smithsonian National Zoological Park in Washington, D.C. “This paper clearly points to an osmoregulatory mechanism.” This insight follows other, potentially promising findings reported in March and in late August that certain skin bacteria can protect against fungal infection. Matthew Becker, now a student at Virginia Polytechnic Institute and State University in Blacksburg, Virginia, and Reid Harris of James Madison University in Harrisonburg, Virginia, and their colleagues have found that the bacterium, Janthinobacterium lividum, makes an antifungal compound that stops the fungal infection in its tracks. “This is one of the few bits of hope that many of us have,” says Karen Lips, an ecologist at the University of Maryland, College Park. Herpetologists began realizing there was a worrisome trend in amphibians in 1989. By 2004, a global assessment concluded that “amphibians are more threatened and are declining more rapidly than either birds or mammals” (Science, 3 December 2004, p. 1783). At first, researchers blamed habitat destruction or climate change and changes in ultraviolet radiation. Then in 1998, Australian scientists reported finding a strange fungal infection on dead frogs in the rainforest. About the same time, Smithsonian researchers made similar observations in captive frogs, and in 1999, with the help of Joyce Longcore of the University of Maine, Orono, they described B. dendrobatidis and showed that it caused the deadly infections. Of the 120 amphibian extinctions since 1980, about 90 are attributed at least in part to the fungus, says Gratwicke. Six years ago, Voyles began trying to find out what made the fungus so deadly. She and her colleagues had very little to go on. These fungi weren't known to attack vertebrates, and the “attack” was just skin deep. Moreover, “light microscopy and traditional methods used to determine pathogenesis were ineffective,” Voyles recalls. Two theories held sway. One was that the fungus released a deadly toxin. The other attributed the problems to a disruption in skin function. The skin of amphibians does double duty: maintaining the proper osmotic balance inside the animal and regulating respiration. In 2007, Voyles and her colleagues showed that blood taken from diseased frogs contained very low levels of electrolytes, causing them to suspect a disruption in osmotic balance. Out-of-whack electrolytes affect many physiological processes, including muscle and nerve function and water balance. In the lab, the researchers infected green tree frogs and studied skin samples from these and uninfected frogs. They monitored how well the skin transported electrolytes, tracked biochemical changes in the blood and urine, and kept tabs on heart function using implanted transmitters. The skin of infected frogs was less adept at transporting sodium and chloride ions. Sodium and potassium concentrations in the blood dropped, more so as the infection intensified. The animals' hearts began to beat irregularly and ultimately stopped. When the researchers gave dying green tree frogs electrolyte supplements, frogs that could no longer right themselves recovered enough to turn over and move again. They outlasted the other infected frogs by about 20 hours. “An important next step for this research is to determine what causes the disruption in osmoregulation,” says Becker. Adds Allan Pessier of the San Diego Zoo in California, “It would be good to see these studies repeated and verified in other susceptible amphibians.” In their work with potentially protective bacteria, Becker, Harris, and colleagues have expanded their studies to multiple species. They had come across this bacterium while studying communal nests of four-toed salamanders. The salamander produces a compound called violacein that's toxic to B. dendrobatidis. In March, they reported in the ISME Journal that putting this bacterium on the skin of infected mountain yellow-legged frogs averted death from the fungal infection. They have now tested red-backed salamanders. As they described online 28 August in Applied and Environmental Microbiology, some salamanders have violacein on their skin already, likely produced by endemic bacteria. But adding more bacteria increased the concentration of violacein. “The study clearly demonstrated that violacein concentration on amphibian skin can be manipulated by adding symbiotic bacteria,” says Doug Woodhams, a disease ecologist at the University of Zurich in Switzerland. “By manipulating the microbial community on amphibian skin, conservationists may be able to enhance disease resistance and prevent catastrophic amphibian declines.” 3. China # Scientists Line Up Against Dam That Would Alter Protected Wetlands 1. Li Jiao* XINGZI COUNTY, CHINA—In an annual rite of autumn and winter, millions of migratory birds, including endangered white cranes, descend on Poyang Lake, China's largest body of fresh water. But the vital wintering grounds may be at risk. A proposed dam across Poyang's northern end, 27 kilometers from the Yangtze River, would destroy delicate habitat and impede rare Yangtze finless porpoises from reaching spawning areas, scientists argue. The ecosystem “would change fundamentally,” says wetland ecologist Chen Kelin, director of Wetlands International-China. In an 11th-hour bid to derail the dam, Chen and other scientists outlined their concerns in two letters this past summer to China's premier, Wen Jiabao, chair of the State Council. Their appeal seemed to fall short: On a visit here late last month, Chinese Vice-Premier Li Keqiang endorsed the project's basic direction while stipulating that “the dam needs further scientific input” and that it must protect Poyang's ecology. But in a surprising development, the State Council ordered critics and the dam's backers—the Jiangxi Province government—to thrash out their differences in Beijing. At the meeting last week, scientists argued that the present proposal's costs outweigh its benefits and pressed Jiangxi officials, led by Hu Zhenpeng, the province's vice governor from 1999 to 2008, to shelve plans for the dam, pending further research. “Until now, the project of Jiangxi government is far from being demonstrated as necessary,” says Li Wenhua, an ecologist at the Institute of Geographical Sciences and Natural Resources Research (IGSNRR) of the Chinese Academy of Sciences in Beijing. “The government should organize scientists of different research fields to study the project and judge whether to build the dam,” adds IGSNRR geographer Sun Honglie. “Balancing ecology and development is necessary.” Poyang is more and more precious, Li says, because many wetlands of the Yangtze River basin are gone. In recent decades, wetlands in the middle and lower Yangtze, upstream of Poyang, “have been seriously degraded” as developers fill them in, says ecologist Lei Guangchun, dean of the nature conservation school at Beijing Forest University. That makes the relatively undeveloped Poyang more critical to preserving ecosystem function, he says. A section of Poyang is one of seven wetlands that China first protected under the international Ramsar Convention in 1992. One iconic winter resident is the white crane: The 4000 or so individuals that flock here account for 95% of the remaining population, says Zhang Zhengwang, a professor at Beijing Normal University and secretary general of the China Ornithological Society. The big draw for cranes and other migratory birds are Poyang's shallow waters and marshes, ideal for wading and spearing fish with bills. Proponents argue that a dam would even out Poyang's water fluctuations, which have grown wilder in recent years. During the summer monsoon season, the Poyang watershed, covering 162,200 square kilometers, serves as a spillway for the Yangtze. Lake waters retreat in autumn and winter, and in recent years—perhaps because of the massive Three Gorges Dam upstream—sections have dried up altogether, causing huge losses for fisheries. Convinced of the economic benefit of stabilizing lake levels, Jiangxi's government in March 2008 aired plans for a dam about 2.8 kilometers long that would keep Poyang flush in winter, when lake water typically drains into the Yangtze. Sluices would remain open from April to October, when the water level is higher, allowing free passage to the Yangtze for fish and porpoises, Hu says. A dam, he and others argue, would both improve water quality and safeguard bird habitat. Many scientists disagree. “Based on our own research and other available data, [we] concluded that the proposed water-control structure at the outlet to Poyang Lake would have a significant, negative impact on cranes and other wintering water birds,” says James T. Harris, vice president of the International Crane Foundation in Baraboo, Wisconsin. Stabilizing lake levels would mean that in winter, “almost all” migratory bird habitat would be lost, Harris says. “The water would be too deep for the birds to access food,” he says. “The change in winter water depths would dramatically impact large populations of rare water birds and might lead to the extinction of the Siberian Crane,” adds Jeb Barzen, field ecology director at the International Crane Foundation. In a letter to Wen last June, Chen Kelin and 26 other scientists warned that a dam would “deeply damage” Poyang's ecology and wetland biodiversity. Then in September, 15 senior scientists sent a second letter arguing that stabilizing Poyang's water levels “will trigger a fundamental change of wetland vegetation” and disrupt the food chain. In a March 2009 letter to China's foreign affairs minister, Yang Jiechi, the Ramsar Convention's secretariat reminded that treaty parties are required to “maintain the ecological character of all designated Ramsar sites.” The secretariat, based in Gland, Switzerland, wondered whether the dam would reduce Poyang's water quality and lead to algal blooms, and whether an increased sedimentation rate would erode Poyang's flood storage capacity. “We are concerned as much with the health and livelihood of the human communities that depend on the wetlands, as with ensuring that the function and values of the wetland is maintained for future generations,” the secretariat said in a statement to Science. Dam backers argue that such concerns are overblown. The Ramsar-protected wetlands cover only 224 square kilometers, or 5% of Poyang's area, says Sun Xiaoshan, director of Jiangxi's Water Resources Department. “We will protect these wetlands,” he says. Hu adds that it doesn't make sense to allow vast areas of Poyang to dry out in winter and says further research is needed to determine the lake's appropriate level and how best to operate the dam. He acknowledges that a dam will reduce flow rates into Poyang and increase eutrophication risk—but this is a problem that managers “can guard against.” Based on the discussions at the meeting, some scientists say the case against a dam is watertight. Others are not sure. “The dam must meet strict environmental criteria,” says Xia Qing, an ecologist of the Chinese Research Academy of Environmental Sciences in Beijing. He and others hope that Jiangxi officials at least apply the brakes and involve outside experts in assessing Poyang's future. Adds Chen Zhikai of the China Institute of Water Resources and Hydropower Research in Beijing, “Nobody can evaluate the dam without further research.” • * Li Jiao is a writer in Beijing. 4. ScienceNOW.org # From Science's Online Daily News Site Black Hole Conditions, Right Here on Earth A team of researchers has created conditions analogous to those found outside of a black hole by blasting a plastic pellet with high-energy laser beams. The advance should sharpen insights into the behavior of matter and energy in extreme conditions. Trust Is Only Skin Deep Good looks can take you far. Strangers rate attractive people as more trustworthy and honest; lookers earn more money, too. Now, scientists report that this deferential treatment may lead the beautiful to be more trusting when they know others can see them. Radio Waves “See” Through Walls Researchers have discovered that an array of radio transceivers—devices that send and receive signals—can track people's movements behind walls. Possible uses include detecting people trapped in burning buildings, controlling lighting or heating and cooling systems as people enter or exit rooms, and spotting burglars or enemy soldiers. Mother's Cancer Can Infect Her Fetus A startling case in Japan has confirmed that pregnant women with cancer can pass the disease to their fetuses. These transmissions, normally blocked by the placenta, are rare, so the work likely won't change how doctors screen or care for pregnant women. But scientists say the case could help illuminate how cancer foils the body's immune system. Read the full postings, comments, and more on sciencenow.sciencemag.org. 5. Archaeology # Archaeologists Alarmed by Turkey's Proposed Dig Rules 1. Michael Balter Proposed new rules governing foreign-led excavations in Turkey are causing alarm and confusion among archaeologists, who fear that the regulations could make it very difficult for foreigners to dig in the country. The draft regulations, drawn up by Turkey's Culture and Tourism Ministry, would apply to the 43 foreign excavations currently under way and possibly to an additional 34 foreign-led archaeological surveys. They could require that each excavation season last at least 4 months and that a Turkish co-director be appointed for each dig. A number of foreign governments and archaeological institutes have expressed their concerns to Turkish officials, who met on the issue last week. As a result, a ministry spokesperson now says, the proposed rules may be revised. Archaeologists are worried because most teach and follow academic schedules. The 4-month rule “would effectively eliminate the possibility for most U.S. researchers to conduct fieldwork in Turkey,” says John Yellen, archaeology program director for the National Science Foundation in Washington, D.C. Nicoletta Momigliano, an archaeologist at Bristol University in the United Kingdom and co-director of a dig at prehistoric Çaltilar in Turkey, says that if her team had to carry out “4 months of actually digging or surveying, it would be impossible to carry on. No academic in the U.K. can afford to have such a long field season.” Turkish officials say the rules were spurred by several issues. Some foreign archaeologists take too long to finish excavations and publish results, says Mesut Özbek, counselor for culture and tourism at the Turkish Embassy in Washington, D.C. “Some of these excavations have been going on for more than 100 years,” Özbek says, citing the Austrian-led dig at the classical city of Ephesus on Turkey's Aegean coast. In other cases, he adds, dig “directors who run out of time do not properly protect their dig sites, and they get attacked by treasure hunters, get looted, or get damaged by nature, rain, and snow.” Özbek says that archaeologists should not worry about the 4-month rule, because if they have to leave early, the Turkish co-director can finish the season. “Turkish archaeology is at an advanced stage.” But Sabine Ladstätter, director of the Austrian Archaeological Institute in Vienna, which sponsors the Ephesus excavations, says there are good reasons why the dig there has gone on for 115 years: “The aim of an excavation is not to finish it. This is a huge site, one of the biggest cities of the classical world.” Ladstätter adds that the Austrian-led team has carried out numerous restoration projects at Ephesus, most notably the Celsus library, built in 117 C.E. and admired by nearly 2 million tourists each year. She says Turkish archaeologists are fully involved: Of the 174 researchers working at the site, 46 are from Turkey. Some Turkish archaeologists have publicly expressed opposition: In July, the Istanbul branch of the Turkish Archaeology Association published a letter on its Web site saying that the obligation to appoint Turkish co-directors could jeopardize “the future of Turkey's archaeology.” One reason, some researchers say privately, is that Turkey may not have enough archaeologists to go around, as Turkish researchers are busy working their own sites. Foreign digs, which have long been welcome in Turkey, make up nearly one-third of the country's roughly 140 excavations. Co-directors are not required in many other countries that welcome foreign archaeologists, including Egypt and Jordan. After officials from several countries, including Austria, Germany, and the United States, conveyed concerns to the Turkish government, the culture ministry scheduled a meeting with foreign and Turkish archaeologists for 15 October. The week before, the ministry reportedly told foreign archaeologists that it was canceled. However, Özbek told Science that Culture and Tourism Minister Ertuğrul Günay did meet with culture ministry officials and Turkish archaeologists; only foreigners were excluded. But there are signs that the foreign archaeologists' concerns are being heard. According to Özbek and others familiar with the meeting, the ministry plans to hold more discussions before making a decision and is considering including dig preparation and publication as part of the 4-month work period. 6. Science in Society # Hong Kong's Darwin Defenders Declare Victory in Teaching Fracas 1. Richard Stone BEIJING—As a year of honoring Charles Darwin and his theory of evolution draws to a close, scientists in Hong Kong are celebrating a partial victory in what is likely to be an ongoing war against proponents of teaching creationism and intelligent design in secondary schools. “We have kept the creationist barbarians from the gate,” says aquatic ecologist David Dudgeon, faculty board chair at the University of Hong Kong (HKU), about a decision last month by Hong Kong's Education Bureau to discount language in new science curriculum guidelines that had opened the door to teaching creationism and intelligent design in secondary schools. But their triumph is bittersweet. The Education Bureau has not revised the guidelines, choosing instead to issue its pro-evolution statement as an annex. And no one expects the few dozen schools in Hong Kong that openly espouse creationism to suddenly abandon it. “It appears that the bureau is unwilling to confront the Christian schools openly, and the schools will probably continue to teach creationism as part of the science classes,” says astronomer Sun Kwok, HKU's science dean. At first blush, cosmopolitan Hong Kong seems an unlikely bastion of creationism and intelligent design, which posits that the complexity of life requires action by an intelligent agent. But looks can be deceiving. Although all Hong Kong schools are publicly funded, most are run independently, and many have church affiliations, says Kwok. “Fundamentalist Christianity percolates through schools, government, and other authorities in Hong Kong, and it informs attitudes towards gays and other social issues,” Dudgeon says. “It is the elephant in the room” that no one talks about. That changed in February when Dudgeon, Kwok, and like-minded colleagues began raising a ruckus over the “New Senior Secondary Biology and Combined Science Curriculum and Assessment Guide,” a revision aimed at bringing Hong Kong's education system in line with international norms. Many changes were positive, but one rang alarm bells. The previous guidance suggested, vaguely but reasonably, that teachers “guide students to review the differences between scientific theories and other nonscientific modes of explanation, e.g. religious, metaphysical or philosophical.” The new wording seems to put religious beliefs on an equal footing with evolution: “In addition to Darwin's theory, students are encouraged to explore other explanations for evolution and the origins of life, to help illustrate the dynamic nature of scientific knowledge.” Some people, Kwok says, perceived that the Education Bureau had “yielded to pressure from religious schools.” So Kwok and HKU faculty members mounted a public campaign against what Kwok calls “pseudoscience subjects such as intelligent design, astrology, and UFO studies [that] have no place in our science curriculum.” Hong Kong newspapers ate it up. But many religious leaders rallied behind the Education Bureau—as did some members of the scientific community. In May, a group of academics and high school teachers called the new guidance “stimulating, balanced, and nonbiased.” Their statement said that “there is a real legitimate scientific controversy over Darwinian Theory. … Alternative explanations to Darwinian macro-evolution should thus be explored so long as they are based on rational and empirical grounds.” One of the signatories, HKU physicist Chris Beling, argues that intelligent design concepts should be taught in addition to Darwinian theory. Intelligent design “may or may not be the answer to present problems in biological origins,” he says, “but if the [HKU] science faculty keeps on shouting that Darwinian theory is the answer and drowning out other voices, it is clearly unhealthy for the progress of science and for the promotion of critical thinking amongst students.” After weeks of rancor, the Education Bureau sided with the Darwinian camp. In a 9 September letter to the Concern Group for Hong Kong Science Education, curriculum officer Cheung Kwok-wah, writing on behalf of the education secretary, revealed an annex to the curriculum guide that notes, “Creationism and Intelligent Design are not included in the Biology Curriculum framework nor are they considered as an alternative to Darwin's theory.” Kwok, for one, is not satisfied. “The bureau has not changed the curriculum guide or issued a clarification statement to the schools,” he notes. In the meantime, Kwok has been overseeing an effort to strengthen HKU's science curriculum as the university moves to a 4-year program. The science faculty is designing “foundation courses” that, starting in 2012, he says, would “provide all science students with a broader education and ensure that all students are exposed to the scientific way of thinking.” Secondary schools are likely to be more resistant to change, however. Members of the Concern Group—now with more than 630 members—recently discovered that one biology textbook published by Oxford University Press (China) Ltd. and endorsed by the Education Bureau refers to intelligent design ideas and two creationist Web sites. Some schools are using it, says information technologist Virginia Yue, a founder of the Concern Group. “We were shocked and appalled by such shameless religious proselytizing under the guise of science,” says Yue, whose group is now mulling its next move. Their options may be limited, however. “Unless we police classrooms,” Dudgeon says, “I think the matter must rest.” 7. ScienceInsider # From the Science Policy Blog Although the number of swine flu cases is rising in the United States, deliveries of pandemic vaccine have been delayed. The Department of Health and Human Services, which had hoped to deliver at least 40 million doses by the end of October, is now estimating 30 million or fewer. The FBI arrested U.S. space scientist Stewart David Nozette 19 October on charges of attempted espionage. Nozette had a security clearance at Lawrence Livermore National Laboratory. Story Landis, director of the National Institute of Neurological Disorders and Stroke, resigned from the Interagency Autism Coordinating Committee. She accidentally left notes that angered autism advocates. The U.S. Congress will hold its first hearing early next month on proposals to deliberately tinker with the climate. Legislators who support curbing carbon emissions have shied away from geoengineering out of concern that talk of a technical fix could distract from those efforts. An Iranian lawmaker who helped investigate alleged plagiarism by Iran's science minister says that the case isn't plagiarism because the results are a “genuine scientific work.” Sections of a 2009 engineering paper written by Minister Kamran Daneshjou were verbatim copies of work by other scientists. The Large Hadron Collider at CERN near Geneva, Switzerland, is ready to begin smashing particles, officials say. The$5.5 billion accelerator broke down 13 months ago after operating for only 9 days.

The Jackson Laboratory, the mouse-research powerhouse in Bar Harbor, Maine, is thinking about building a branch in south Florida as part of a move into personalized medicine.

For more science policy news, visit blogs.sciencemag.org/scienceinsider.

8. Astronomy

# Race for the Heavens

1. Yudhijit Bhattacharjee

Two very different telescope projects are jostling to give the United States its biggest-ever eye on the sky. Can the country afford both?

In 1977, Jerry Nelson, an applied physicist at the Lawrence Berkeley National Laboratory in California, made a bold proposal to the University of California (UC). The university was looking to build a 10-meter telescope—twice the size of the Hale Telescope at Mount Palomar, which for 3 decades had been the largest telescope in the country. Nelson was convinced that standard telescope mirrors—“monoliths” made from a single piece of glass—had reached their limits. Instead, he proposed to make the primary mirror for the new telescope from a few dozen thin, hexagonal segments joined together into a smooth parabolic surface.

“I knew I could build a 10-meter monolith. But I didn't want to, because it would be the last of the dinosaurs,” says Nelson, whose concept was greeted with skepticism by UC astronomers. “I didn't just want to build a telescope. I wanted to build a system that could be extrapolated into a bigger telescope in the future.”

Meanwhile, a physicist named Roger Angel was melting Pyrex dishes in a makeshift backyard kiln in Tucson, Arizona, to figure out how to make monolithic mirrors bigger and better. Although less radical than Nelson's approach, Angel's posed equally daunting engineering challenges. The two men would exchange competitive jibes at conferences. Making no secret of his view of monoliths as obsolete, Nelson—a native Californian with an irreverent style—would jokingly ask Angel why he kept wasting time on a dead-end technology. Angel, a transplanted Brit of gentlemanly bearing, would smile back and note the risks of an untested one.

By the early 2000s, each side had points on the scoreboard. Nelson's team had built segmented mirrors for the twin 10-meter Keck telescopes on the summit of Mauna Kea in Hawaii; Angel's had fabricated 6.5-meter monoliths for the two Magellan telescopes at Las Campanas in Chile. Those successes set the stage for a new contest, now in full throttle: building the world's largest telescope. For the past 5 years, Nelson and his colleagues at UC have been working on plans for the Thirty Meter Telescope (TMT)—whose primary mirror will be a glinting mosaic of 492 hexagonal segments controlled with such precision that even light won't discern the edges between them. Meanwhile, Angel and his collaborators have set their sights on building the Giant Magellan Telescope (GMT)—whose seven monolithic 8.4-meter mirrors, arranged like flower petals, will function as a primary mirror 24.5 meters in diameter.

If the telescopes are built—TMT on Mauna Kea in Hawaii, GMT at Las Campanas—each will capture images up to 10 times sharper than today's best ground-based telescopes. Both will shoot for the same scientific goals, which include bringing into focus the first stars and galaxies, studying the formation of planets and stars, understanding the growth of black holes, and probing the nature of dark matter and dark energy. And both will cost a fortune: The segmented TMT's price tag is $1 billion; GMT's is$700 million.

So far, neither side—UC and the California Institute of Technology for TMT, and a consortium led by Carnegie Observatories and the University of Arizona for GMT—has come close to securing the total funding it needs. “These facilities are so big that they could die of their own weight,” warns Richard McCray, a professor emeritus at the University of Colorado, Boulder. Even if both GMT and TMT get built with little federal support, he says, the U.S. National Science Foundation (NSF) would be hard pressed to help out with the substantial operating costs of each. Given the funding challenges, some astronomers say the two sides should have joined hands to build one telescope to rival the European Southern Observatory's proposed 42-meter segmented-mirror telescope, the European Extremely Large Telescope (E-ELT), which is also in the works (see sidebar, p. 514).

Such a merger has certainly crossed the minds of key figures on each side, but everyone agrees that it's too late now. Differences in technology, personal egos, and institutional rivalries have driven an insuperable wedge between the two efforts. “This is a human endeavor,” says Nelson, adding that to him, the two projects “look like oil and water.” But even though that divide implies an arduous task ahead for both GMT and TMT, along with the risk of delays or failure should funds run short, leaders of both TMT and GMT project absolute confidence that their artists' conceptions, videos, and miniature models are destined to become the real thing. And officially, at least, the two sides conjure up a future in which both telescopes coexist. “Let two flowers bloom, I say,” says Angel.

## Worlds in collision

Nelson and Angel are both stars, now in their 60s, with gray hair and membership in the National Academy of Sciences. Their different backgrounds and contrasting personalities in some ways mirror their approaches to telescope building: radical versus traditional, new-worldly and risky versus more tried and true.

The son of a Lockheed tool planner and raised in a rural California town, Nelson grew up a tinkerer with an affinity for electronics. He learned lathing, welding, and polishing at the machine shops of Caltech while receiving an undergraduate degree in physics. Nelson has a cheerful, round face and a prosperous middle, likes to wear Hawaiian shirts, ends his e-mails with “Aloha,” and grins widely when he's mocking the competition. Student-like, he often carries a backpack slung across his shoulder.

Working on the Keck design 30 years ago, Nelson had to solve two main challenges in constructing the segmented mirror. One was polishing each mirror segment into an aspherical surface, so that the segments would together make a dish. The other was controlling the segments precisely to make them act as one seamless reflector.

Standard polishing renders surfaces spherical. To get around the problem, Nelson—along with Coby Lubliner, a civil engineer at UC Berkeley—prestressed each piece with weights before polishing it into a spherical surface. When the weights were removed, the segment elastically relaxed into the desired shape.

Nelson and his colleagues solved the control problem with electronics and computing, using edge sensors and pistonlike actuators to keep the segments perfectly positioned against the destabilizing effects of wind, gravity, and temperature change. It was a scheme that many considered too complex to work. “In 1980, control systems were like, ‘How do you spell that?’ to the astronomical community,” chuckles Nelson. Clearing such practical hurdles, he says, was key to moving the once-outlandish idea of segmented mirrors into the astronomical mainstream. “The world is full of dreamers who say, ‘Gee, I'll get in my car, I'll fly to work, then I'll go under water.’ The question is, do you know how to do it?”

Angel grew up in foggier climes than Nelson did—in a suburb of Manchester, U.K.—but like his competitor, he studied physics in college and spent time at Caltech on a master's degree. After earning a doctorate from the University of Oxford, U.K., he flitted between different fields of high-energy physics and astrophysics before settling on optics and mirror design as a young faculty member at the University of Arizona. Angel is slim, bespectacled, and more reserved than Nelson. He seems to f it the mold of the absent-minded professor, asking students for help in turning on the lab coffeemaker and driving an old truck through Tucson wearing a straw hat and gloves to shield himself against the merciless Arizona sun.

Angel's innovation in the early 1980s was to design monolithic mirrors that weighed one-fifth as much as conventional mirrors, allowing them to be cast in larger diameters, and that cooled more quickly at night, which would reduce the image distortion caused by air turbulence at the mirror surface. The trick was to melt cheap borosilicate glass into a mold with hexagonal columns made of heat-resistant foam. Spinning the cast spread the glass into a saucerlike shape, with some of the glass trickling down to fill up the empty space between the foam columns. Once the glass solidified, the foam was washed away, producing a thin, smooth top supported by a hollow, honeycombed base a few inches tall. To polish the surface, Angel and his colleagues built a computer-controlled precision lathe that ground down the glass to nanometer-level accuracy.

In the 1980s, Angel set up a warehouse-sized laboratory under a wing of the university's football stadium to make and test these mirrors. The lab in recent years has delivered two 8.4-meter mirrors for the Large Binocular Telescope on Mount Graham in Arizona, which began doing science in 2007. The seven-part GMT mirrors will have a more complex topology than the binocular mirrors, Angel says, but each will be the same size they were and can be made with the same proven technology. His team recently cast the first 8.4-meter mirror for GMT and is now polishing it.

“With the making of the first segment, we have pretty much retired the risk of how you put the telescope together,” he says. He has come home in the middle of the day to tend to his ailing cat. Sunlight bouncing off a pool in the back dances on his face as he peels a pomegranate at the lunch table. Making the 492 segments of the competitor TMT work together, Angel says, is inherently riskier than GMT's seven-piece design: “It's a matter of the devil you know versus the devil you don't.”

Caution and thrift come up a lot when members of the two teams pitch their projects. “If you look at the two telescopes, you say that [TMT] is really sexy; this [GMT] is old-fashioned stuff,” says Jonathan Kern, an engineer with GMT. “But this is old-fashioned for a reason. We are not trying to do anything that hasn't been done, that we can't put a cost on.”

Nelson, who otherwise enjoys the label of risk-taker, stresses that segmented mirrors are now a rock-solid technology, too. Controlling 492 segments (inconceivable when the 36-segment Keck mirror saw first light 16 years ago) is “completely trivial” for modern computers, he says. “The bottom line is that today segmented mirrors are cheaper per square meter than monoliths,” and the savings on mirror construction far outweigh the cost of more-powerful computing and denser actuators. The American telescope projects' transatlantic rival, the E-ELT, will use 1000 segments, Nelson notes. “Nothing can stop a good idea,” he says with a grin.

## Winner take all?

The race for telescopic supremacy began in 1999, when astronomers'decadal survey—an official rank-ordered “wish list” of proposed projects that researchers submit to the government—cited a giant telescope as a top priority. Nelson's group was first off the block, with a proposal for what was then called the California Extremely Large Telescope (CELT).

At first, the leadership at Carnegie Observatories mulled the idea of joining CELT. It was a controversial proposal. Carnegie Observatories and Caltech, both nurtured by George Hale and located 8 kilometers apart, had been managed jointly until 1971, when differences culminated in a divorce. Rivalry ran deep.

When Carnegie researchers approached astronomers at Caltech with an offer to collaborate on CELT, they were turned away, according to scientists on both sides who did not wish to spell out the details. Stung by the rebuff, researchers at Carnegie joined with other institutions to create what is now Angel's GMT consortium. “No question that we got going because the other group was making headway,” says Stephen Shectman, project scientist for GMT and a researcher at Carnegie. Nelson and others on TMT acknowledge that they were less than thrilled to see GMT entering the arena. “They wanted to be the only U.S. project in this area,” Shectman says.

Behind-the-scenes maneuvering followed. In 2003, TMT sent UC Berkeley astronomer Richard Ellis to the Harvard-Smithsonian Center for Astrophysics, a Magellan partner, to woo Harvard away from GMT and into TMT. Josh Grindlay, a Harvard University researcher who was involved in the talks, calls Ellis's visit “a political move … to squash the competition.” Nelson is unapologetic. “Harvard's rich. We needed rich partners,” he says.

Grindlay says some at Harvard were tempted but that loyalty to the Magellan consortium and confidence in the GMT proposal—“which really is simpler”—carried the day. Friends at Caltech still jokingly ask him if Harvard would like to join TMT, he says: “They say you might as well join us because there may not ever be a GMT.”

Nelson's TMT scored a coup in June 2003 when it signed a technical agreement with a major users' group. The Association of Universities for Research in Astronomy (AURA), a consortium of some three dozen U.S. and international institutions that channels NSF funding to astronomers and facilitates access to observatories, nailed down terms of collaboration. The partnership seemed to bring TMT one step closer to NSF funding. Angel and his colleagues fired off a letter to AURA complaining that it was essentially picking a winner without an open competition.

In late 2006, on the advice of NSF, the TMT-AURA partnership was suspended. AURA has since served as the program manager for all technology development related to giant telescopes and has so far provided GMT and TMT with about $17.5 million each for design work. However, TMT is still lobbying AURA to resume the partnership, arguing that it is the more developed of the two projects and deserves exclusive NSF support. “[TMT's] board is concerned that NSF funding may not support timely substantial public participation in two US-led large telescopes and urges AURA … to examine carefully the merits and feasibility of advocating support for two large US telescopes in the context of the upcoming Decadal Survey,” TMT board chair Henry Yang wrote in a letter to AURA in April 2008. The 2010 survey is expected to be completed by the middle of next year. NSF officials won't comment on which project is ahead or what its plans are for supporting either telescope in the future. But it is keeping tabs on the progress of both. This summer, a panel appointed by AURA submitted community assessments of TMT and GMT to NSF. The reports do not go into a comparative analysis, but they suggest that TMT is further along. “We believe [TMT] will be ready within a few months for an NSF-led Preliminary Design Review, and could seek funding assistance from the NSF MREFC [Major Research Equipment and Facilities Construction account] in the near future,” the panel writes. GMT, by contrast, needs to make “significant progress” in a number of technical and managerial areas to reach the same stage. Wendy Freedman, director of the Carnegie Observatories and chair of the GMT board, acknowledges that the projects are at different stages but says the gap between them is more apparent than real. “We've concentrated on different things,” she says. “They have completed their detailed design study, while we've cast the first mirror.” TMT also took an early lead in fundraising thanks to a$200 million gift from the Gordon and Betty Moore Foundation and a pledge by UC and Caltech to come up with another $100 million. “When you have a big pile of cash on the table, it shows that somebody has confidence that the thing is going to get built,” says Michael Bolte, a UC Santa Cruz astronomer and a TMT board member. Canada has pledged 25% toward construction and operation, and Japan is interested, he says. GMT has been working the international circuit as well. In July, the Australian government promised$72 million for the project. Korea is a partner, too, although the details of how much it would contribute are not available. “We're about a third of the way there,” says Patrick McCarthy, director of the GMT consortium. But he is reluctant to provide a breakdown. Both sides have been aggressively courting China and India, McCarthy says, noting that E-ELT officials have been making similar trips.

Amid the scramble for funding and favor, one question looms: Is the game really winner take all? Does NSF have to choose one telescope at the end of the day?

Freedman believes it does not. One possibility, she says, would be for the agency to provide 25% of operating costs to both and guarantee a quarter share of observing time on both for the U.S. community. Furthermore, Angel says, differences between the two projects could lead to different kinds of science. TMT will scan the northern sky, GMT the southern; TMT's adaptive optics system may be better at resolving point sources, whereas GMT's system might produce better images of wider fields, making it more appealing for cosmology.

Nelson takes a hard line. “TMT is inevitable,” he says. “I am just doing my job, making it happen.” But even he won't entirely rule out a two-scope solution. “If you go back to 1980, you could easily have said, ‘Oh, these telescopes are so expensive, they'll never get built’—and lo and behold, there are several 6- to 10-meter telescopes today that back then were the tiniest glint in a few people's eyes.” He pauses, then adds: “So, maybe we'll build both.”

9. Astronomy

# The Colossus of Europe

1. Yudhijit Bhattacharjee

The European Extremely Large Telescope will outsize the U.S. entries in its class, the Thirty Meter Telescope and the Giant Magellan Telescope, by a fair margin, with a primary mirror 42 meters in diameter.

With a 100-meter primary mirror, it would have been the big daddy of all telescopes, worthy of the label “Overwhelmingly Large” (OWL) bestowed by its architects at the European Southern Observatory (ESO). Now, astronomers joke that the acronym means “Originally Was Larger.” Even so, the scaled-down successor that ESO has committed to building—the European Extremely Large Telescope (E-ELT)—would still outsize the U.S. entries in its class, the Thirty Meter Telescope and the Giant Magellan Telescope (see main text), by a fair margin, with a primary mirror 42 meters in diameter.

E-ELT's estimated cost of \$1.5 billion also makes it the most expensive of the three. Its funding prospects, however, seem rosier than those of GMT and TMT because governments are backing it: The 14 member states of ESO have agreed to provide a third of the money over the next 10 years. To make up the difference, ESO members are discussing whether to increase their contributions to the ESO budget, attract outside partners, or do both, says Jason Spyromilio, director of the E-ELT project office.

The project's planners, who are currently finishing up a detailed design, want to build the primary mirror with 1000 segments about the same size as the hexagonal panels in TMT. Spyromilio says using a handful of larger monoliths between 7 and 8 meters in diameter could also have worked. “There is no a priori clear solution that would say one is better than the other,” he says of the two designs. “The selection reflects the different risks that each project associates with its supply chain.”

The resolution provided by E-ELT's collecting area of 1200 square meters—nearly twice that of TMT and three times that of GMT—will enable a lot of exciting science, says Spyromilio. “Anice example might be the power of imaging exoplanets. Here the E-ELT will achieve a contrast about an order of magnitude better than the next best telescope,” he says, adding that E-ELT in principle will be able to detect exoplanets as small as Earth. Officials hope to pick a site for the telescope from among candidate sites in the Canary Islands, Chile, Morocco, and Argentina by the end of this year.

10. Green Energy

# Another Biofuels Drawback: The Demand for Irrigation

1. Robert F. Service

New U.S. mandates are prompting farmers to plant more corn in areas of the country that require irrigation. The move could trigger water shortages and water-quality problems.

At first blush, it's easy to make the case for biofuels. By converting crops into ethanol or biodiesel, farmers can reduce demand for imported oil, lower national dependence on authoritarian governments in the Middle East, and potentially cut greenhouse gas emissions.

But dig a little deeper, and the story gets more complicated. Biofuels promise energy and climate gains, but in some cases, those improvements wouldn't be dramatic. And they come with some significant downsides, such as the potential for increasing the price of corn and other food staples. Now, a series of recent studies is underscoring another risk: A widespread shift toward biofuels could pinch water supplies and worsen water pollution. In short, an increased reliance on biofuel trades an oil problem for a water problem.

“It really means a greater potential for agricultural pollution of the waterways, eutrophication of the Gulf Coast, and a significant increase in water use, which may produce localized shortages,” says Pedro Alvarez, an environmental engineer at Rice University in Houston, Texas. But just how severe such shortages could become remains unclear. They could be mitigated, some researchers suggest, by steady improvements in crop yields and an increasing reliance on nonfood feedstocks for making ethanol.

In 2007, the perceived benefits of biofuels helped spur the U.S. Congress to pass the Energy Independence and Security Act (EISA), which mandated a nearly fivefold increase in U.S. ethanol production, to 117 billion liters, by 2022. Of this amount, nearly half is slated to come from corn ethanol by 2015. Most of the rest will be added from cellulosic ethanol, which is made from agricultural wastes and other feedstocks. Biodiesel and other “advanced biofuels” will eventually chip in about 10%. Although cellulosic ethanol and other advanced biofuels aren't yet cheap enough to compete with corn ethanol, their prices are expected to decline over the next several years.

Growing all those feedstocks will be a stretch, especially for irrigated lands. Meeting the 2015 mandate alone would require 44% of the corn produced in the United States in 2007. That's in addition to existing food and feed corn needs, assuming no change in demand or prices. According to a report in January by May Wu and colleagues at Argonne National Laboratory in Illinois, 98 liters of irrigation water are required on average to produce a liter of corn ethanol. (Estimates range between 10 and 324 liters of water per liter of ethanol, depending on where the corn is grown.) Together, the need for more corn and the mandates for biofuels could increase water demand by some 5.5 trillion liters a year.

Making matters worse, other U.S. energy sectors are growing and increasing their demand for water. Another recent report from Argonne by Deborah Elcock, an energy and environmental policy analyst, for example, found that water consumption for energy production in the United States will jump two-thirds between 2005 and 2030—from about 6 billion gallons of water per day to roughly 10 bgd—driven primarily by population growth. About half of that increase will go toward growing biofuels. According to Elcock's analysis, which is scheduled to be published in the Journal of the American Water Resources Association, the impact from the increase in biofuels is likely to fall almost entirely on the Corn Belt states ranging from the Dakotas, Nebraska, and Kansas eastward to Ohio.

A separate analysis by Charlotte de Fraiture and colleagues at the International Water Management Institute in Colombo, Sri Lanka, underscores the scale of the change. De Fraiture and her colleagues looked at how the expected increase in biofuels would affect countries around the world. They found that the proportion of irrigation water used to grow biofuels was expected to rise from about 2% to roughly 4% worldwide by 2030. But in the United States, the proportion of irrigation water going to biofuels is expected to skyrocket from about 3% in 2005 to 20% in 2030.

So what's the likely impact from this potential increased water use? That depends on where you are, Wu and others say. “Overall, I think there will be some shortages of water introduced by the EISA mandates,” Alvarez says. The potential for shortages is greatest in the western plains states, where average rainfall isn't sufficient to grow corn and biofuel production is increasing, Wu reports. The demands could be particularly challenging for siting biofuel processing facilities. A typical facility might produce 100 million gallons of ethanol a year and use as much water as a town of 5000 people would. Although that amount of water isn't a lot on a national scale, “this can strain local resources,” Wu says. “Water is like politics,” adds Michael Ottman, a crop scientist at the University of Arizona, Tucson. “It's local that counts.”

Another local impact that could hit hard is eutrophication in the Gulf of Mexico, caused by runoff of nitrogen fertilizers into the Mississippi River. Marine ecologists already see the runoff as a primary culprit in the vast “dead zone” that starves the northern Gulf waters of oxygen, killing everything from crabs to shrimp. A report by Michael Griffin of Carnegie Mellon University in Pittsburgh, Pennsylvania, and colleagues in the 15 October issue of Environmental Science and Technology found that even if all the future increase in biofuels were to come from cellulosic feedstocks, the amount of nitrogen pollution in the Gulf of Mexico would continue to rise. That stark forecast illustrates how difficult this environmental problem will be to reverse.

Experts see a few points of light in the gloom, however. Ottman notes that as biofuel production increases, other agricultural water needs may decline. In fact, even as the amount of U.S. land devoted to irrigating corn has grown in recent years, the total amount of irrigated land dropped from 2000 to 2007, as farmers took some land out of production and shifted away from some irrigation-intensive crops such as cotton.

Other factors may curb future water demands. Monsanto and other seed companies, for example, are engineering novel drought-tolerant corn strains that maintain their yields through extended dry spells (see sidebar). And even with current strains, the amount of water needed to grow and process corn ethanol has been dropping in recent years, thanks to increased yields and improvements in processing technology, according to Wu. The amount of water required to produce a liter of ethanol dropped from 112 to 98 liters between 1998 and 2006, Wu reports. The upshot, Wu, Ottman, and others say, is that better methods will partly offset the increased irrigation demands for biofuels.

The potential impact of cellulosic biofuels remains unclear. Many cellulosics will essentially be neutral from a water perspective, says Martha Schlicher, who heads biofuels development at Monsanto. Corn husks, for example, are a byproduct that can be harvested without additional demand for water. And processing switchgrass grown in rain-fed areas requires only between 2 and 10 liters of water per liter of ethanol, according to Wu's report. But Alvarez and others note that as the market develops for cellulosic feedstocks, farmers will have an incentive to begin irrigating switchgrass and other cellulosic ethanol crops to maximize their yields. That could further obscure what has already become a murky case for the advantage of biofuels.

11. Green Energy

# The Promise of Drought-Tolerant Corn

1. Robert F. Service

The biofuels drive is just one of several factors that are increasing the demand for corn and other crops. Seed companies are responding by creating seed varieties able to tolerate drought, which could be particularly useful in reducing water demand in areas dependent on declining groundwater reserves.

The biofuels drive is just one of several factors, along with worldwide population growth and rising incomes, that's increasing the demand for corn and other crops. According to a report this year by the Food and Policy Research Institute at Iowa State University, Ames, demand for grains—primarily corn—is expected to grow over the next decade by about 15%, or roughly 200 million metric tons per year. That will put additional stress on global supplies of fresh water, 70% of which already goes to agriculture.

Growers have traditionally responded to increasing demand by boosting crop yields, bringing more land under cultivation, or both. But now seed companies are closing in on a third option: creating seed varieties able to tolerate drought. According to Winwei Xu, a plant geneticist with a joint appointment at Texas Tech University and Texas A&M's Texas AgriLife Research in Lubbock, such drought-resistant varieties could be particularly useful in reducing water demand in areas dependent on declining groundwater reserves. “The use of drought-tolerant and high-yield corn hybrids is key for sustainable corn production under limited irrigation,” Xu says.

In traditional corn varieties, even a short drought at the wrong time can spell disaster. Corn seeds are properly pollinated if the pollen emerges from the plants at the same time as the corn silks, which capture the pollen and carry it down to individual corn kernels. But if a dry spell comes just as the plants are flowering, the silks may be delayed—drastically reducing the number of fertilized kernels. Drought that comes a little later, as corn grains are beginning to fatten, can also sharply limit growth.

Researchers at Monsanto say they have found a way to blunt some of these effects. Earlier this year, they announced that in field trials, newly engineered corn varieties were largely able to maintain yields under drought-like conditions. The Monsanto corn was engineered to express a cold shock protein from the bacterium Bacillus subtilis. According to Mark Lawson, who heads corn stress and yields research at Monsanto in St. Louis, Missouri, the protein helps the plant manage stress and continue growing. In early field trials, the extra gene helped boost plant yields by 6% to 10%. Monsanto has applied for regulatory approval of this variety, which should be available beginning in 2012 if all goes well, says Lawson, who adds that the company is also working on a second-generation drought-tolerant corn. DuPont's Pioneer Hi-Bred and other agribusiness companies are also gearing up to release drought-resistant corn.

Whether these new varieties can actually lower water use remains to be seen. Lawson says the goal of first-generation drought-tolerant corn is just to maintain yields during extended dry periods. But Michael Ottman, a crop scientist at the University of Arizona, Tucson, notes that farmers don't like dancing on the edge. For regions such as Nebraska that typically supplement rainwater with irrigation water, Ottman doubts that farmers will cut back on irrigation: “Most irrigation farmers don't want to stress their crops and reduce their yield. So it's hard to imagine they will use less water unless the irrigation district limits it.” As a result, even if drought-tolerant corn helps prevent crop losses, it may not actually reduce water use.

12. Behavioral Ecology

# Sex and Social Structure

1. Elizabeth Pennisi

Behavioral ecologists are discovering that social roles in bees may recapitulate the reproductive life cycle of solitary females.

Highly social insects are an efficiency expert's dream come true. Without the benefit of instruction manuals and worker training classes, honey bee queens focus on laying eggs, leaving the details of brood care to an army of workers. One group of workers tends the nest, another forages for food, and neither pays much mind to reproducing. Ants and termites have similar divisions of labor.

As Charles Darwin developed his ideas about evolution and natural selection, he struggled to understand the forces that determine the distinct roles that hive and colony members play. More than a century later—and despite having a much better grasp of genetics—Darwin's successors are still trying to explain how individuals with basically the same genetic makeup can take on such different jobs and appearances.

Now, a series of studies of honey bees by Robert Page and Gro Amdam of Arizona State University (ASU), Tempe, has shown that reproductive traits help shape a honey bee worker's role in life and that ovaries are active players in the process—even if they play little role in reproduction in worker bees. The specialized tasks have their basis in what Amdam and Page call a reproductive ground plan.

“The hypothesis has fundamentally changed the view on the physiological and molecular underpinnings of division of labor in honey bees,” says Klaus Hartfelder of the University of São Paulo in Brazil. There was a time when researchers suspected that special genes led to worker-specific behavior. But now, instead of thinking in terms of individual genes, “we have come to look at this problem in terms of regulatory circuits” that govern reproductive physiology in both solitary and social insects.

Although there is debate about the relevance of the work to social insects other than bees—and at least one study has produced contrary data—the idea is gaining attention. “I think this [idea] has tremendous power to fuel a synthesis of genomics, evolution, and behavior to understand the details of social structures and social evolution,” says Michael Breed, who studies the behavior and ecology of social insects at the University of Colorado, Boulder.

## Ovarian ground plan

The general idea came first from wasps. In honey bee colonies, the division of labor is fixed, with each bee's destiny as queen or worker determined during larval development. But social wasps can be jacks of all trades. Wasp females play queen, nurse, forager, and guard—depending on the circumstances. To Mary Jane West-Eberhard, an evolutionary biologist at the University of Costa Rica in San José, these different roles were reminiscent of the life-cycle stages solitary female wasps pass through. A solitary female produces and lays an egg; then she spends several days provisioning or guarding the larva before producing another egg and repeating the cycle.

In the late 1980s and again in 1996, West-Eberhard laid out her theory that an “ovarian ground plan” lies behind the behaviors of both social and solitary wasp species. The cycle of egg laying, nurturing, and foraging in solitary wasps is governed by the degree of activation of the ovary, and West-Eberhard suggested that social structure arises when parts of this ovarian cycle are suppressed in some nest members, resulting in the division of labor between egg laying, nurturing, and foraging that characterizes the social organization of the nest. “Workers drop egg laying, and queens drop (or greatly reduce) brood-care activities,” she explains.

While West-Eberhard was developing her ideas, Page was embarking on experiments that would eventually fill in molecular details of how such a ground plan seems to work in honey bees. He didn't set out to do that. In 1990, when he was based at the University of California, Davis, Page began breeding two strains of honey bees, one with workers that had a yen for hoarding pollen and one in which workers tended to collect and store nectar. He knew that the amount of stored pollen available influenced hive dynamics, individual behavior, and other aspects of the colony, and he cataloged the behaviors and traits that emerged over time in the two strains. “I wanted to … see how [the experiment] affected elements at [all] levels of organization,” he recalls.

A dozen years later, he had observed several key differences in these strains but couldn't figure out why certain behaviors seemed to be correlated or what underlies the high-pollen-hoarding syndrome. “I'd gotten stuck,” Page recalls. Then in 2003, he read Amdam's Ph.D. thesis. A Norwegian graduate student, she had requested that Page be involved in her thesis defense.

Amdam focused on a yolk protein called vitellogenin in the blood of worker bees. In solitary bees, vitellogenin is produced during the reproductive phase of the life cycle: Blood levels increase before egg-laying, when the bee starts foraging for pollen to provision the nest. Then they decline and remain low as it forages for nectar (see diagram). Amdam had established that nursing worker bees in a social hive produce vitellogenin and convert it into supplementary food for the hive's brood, and she proposed that the protein also regulates the timing and nature of foraging workers' behavior, through an inhibitory influence on juvenile hormone.

Among Page's bees, the high-pollen-hoarding workers tended to start foraging at an earlier age than the strains that had a preference for nectar. Amdam “had a biochemical explanation” that might possibly explain not just hoarding but other behavioral differences, says Page: “I thought, here it is, here is my entry point.” Page suggested that his bees might provide a test of her thesis.

Amdam, who moved to the University of California, Davis, in 2004, collected bees from Page's colonies and tested their blood for levels of various reproductive factors, including vitellogenin. She found that young adults from the high-pollen-hoarding strains had higher levels of vitellogenin than those from the low-pollen-hoarding strains. These findings linked pollen-foraging behavior in sterile worker bees to a protein produced only during the “maternal” or reproductive phase of solitary bees. Amdam and Page proposed that the reproductive cycle of solitary bees became decoupled during evolution to produce a template for the foragers' division of labor in social bees. They called this idea the reproductive ground plan.

A close look at the workers' ovaries indicated that Amdam and Page had come up with molecular support for West-Eberhard's ovarian ground plan. High-pollen-hoarding bees tended to have twice as many egg-forming filaments—which correspond to a larger, more easily activated ovary—and were more likely to develop eggs if the colony lost its queen, Amdam and colleagues reported in 2006. Another study of 500 wild-type bees showed that those with more egg-forming filaments tended to be like the high-pollen-hoarding bees.

In 2007, the researchers cemented vitellogenin's connection to multiple aspects of honey bee society when they used RNA interference to shut down the vitellogenin gene in wild-type bees. The workers began to forage at an even younger age, they preferred nectar, and they lived shorter lives.

The work “provided a link between reproductive potential and pollen foraging,” says Christina Grozinger, who studies behavioral genomics at Pennsylvania State University, University Park. “The West-Eberhard ground plan provided a novel framework for interpreting data related to division of labor in social insects, while the Amdam-Page ground plan provided specific hypotheses which would be tested with molecular tools in honey bees.”

Page, Amdam, and their colleagues have since converged on two genes that may explain both ovary size and behavior, which they reported 2 April in PLoS ONE. One, PDK1, codes for a protein that may influence the number of egg-forming filaments produced during development, as well as food-related behavior in the adult bee; the other, HR46, is a nuclear hormone receptor that may determine ovary size in workers.

## Building a case

Not all the data fully support the reproductive ground plan hypothesis, however. In 2008, a team from the University of Sydney in Australia, led by Benjamin Oldroyd and Madeleine Beekman, looked for correlations in ovary activation and division of labor in a strain of “anarchistic” bees in which some workers lay eggs even in the presence of a queen. They found that anarchistic workers foraged later in life, and some never make that transition. But they saw no correlation with active ovaries and pollen foraging, as the reproductive ground plan would have predicted, they reported 4 March 2008 in PLoS Biology.

Other researchers are not yet convinced that the hypothesis is well-grounded. Ryszard Maleszka of the Australian National University in Canberra even calls the experimental evidence sketchy. “It is not 100% clear if the published experiments are conclusive or just correlations supported by statistics,” he says. Moreover, “it's important to sort out to what extent environmental factors contribute to worker behavior and ovary size.”

But Amdam, who moved to ASU in 2005, is not fazed by the criticism. ASU graduate student Adam Dolezal has evidence, reported in the May issue of Animal Behaviour, that a reproductive ground plan can influence the division of labor in the California harvester ant, Pogonomyrmex californicus. And Amdam's team has found that the honey bee's vitellogenin protein has a flexible region that could enable it to serve a regulatory role.

Seeking to establish causality between ovary size and worker behavior, the group has developed a way to transplant ovaries from one worker to another—say, one that comes from a high-pollen-hoarding strain to a bee from a low-pollen-hoarding strain, or between bees of different ages or behavioral states. In pilot studies, “we see the behavioral changes we expect, which is very exciting. We can now look at how the ovary is talking to the bees,” says Amdam.

Amdam acknowledges that they have yet to show that the reproductive ground plan hypothesis can be applied broadly to other social insects. But she and others are pleased with their progress. “They keep going,” says Bert Hölldobler, an entomologist at ASU, “and are getting more and more support for this concept.”