# News this Week

Science  24 May 2013:
Vol. 340, Issue 6135, pp. 906
1. # Around the World

1 - Kiruna, Sweden
Asian Nations Join Arctic Council
2 - Washington, D.C.
Kepler's Closing Act?
3 - Shanghai, China
H7N9 Hazard Particularly High

## Kiruna, Sweden

### Asian Nations Join Arctic Council

Five Asian countries, including China and India, gained observer status to the Arctic Council at last week's semiannual ministerial meeting. The eight nations with Arctic territory, including the United States, are the only members of the council with decision-making powers, and a number of indigenous groups are permanent participants that can address the council. But many other organizations and countries are nonvoting observers in the primary diplomatic organization determining policy in the region. With predictions of a summertime ice-free route through Arctic waters within a decade, China and others had lobbied hard for a seat at the table as observers.

Following dissent from Canada, however, the council deferred a decision on an observer application from the European Union, possibly due to ongoing disputes over an E.U. ban on seal fur and proposed restrictions on imports of oil produced in the Alberta tar sands.

## Washington, D.C.

### Kepler's Closing Act?

One of the most successful missions in NASA history may be drawing to a close. NASA officials announced on 15 May that the Kepler spacecraft, which monitors 150,000 sunlike stars in search of transiting planets—and has found more than 2700 planetary candidates outside the solar system—can no longer point in a specified direction due to the malfunctioning of one of its reaction wheels. The spacecraft was put into safe mode while engineers work on the problem.

Launched in 2009, the Kepler mission completed its 3.5-year planned run last year, beginning an extended 3.5-year mission in November. Officials were hopeful that it would continue beaming back data until 2016. But that now looks uncertain; the spacecraft needs three reaction wheels to point precisely, and another wheel had already failed last year.

Still, "we are not down and out," says Charles Sobeck, deputy project manager for Kepler at NASA's Ames Research Center in Moffett Field, California. "The spacecraft is safe and stable. We'll proceed with our investigation." Sobeck says that "the mission itself has been spectacularly successful. We have lots of data on the ground still to pore through." http://scim.ag/Keplerend

## Shanghai, China

### H7N9 Hazard Particularly High

The risk that the H7N9 avian influenza virus poses to humans is "unusually serious," noted a joint World Health Organization (WHO) and Chinese National Health and Family Planning Commission report. The report said the possibility that the virus could become transmissible among people is "higher than for any other known avian influenza virus."

The document, which was posted 18 May on the WHO website, grew out of a weeklong investigative mission in late April by four international scientists. The team surveyed Chinese poultry markets and labs to evaluate the severity of the H7N9 outbreak, which infected 131 people by 17 May, killing 36, according to WHO. The report recommends surveillance through the summer, although new cases have dropped off.

2. # Random Sample

## Flight of the Penguin

More than 70 million years ago, the ancestors of penguins could soar through the air. So why did the penguin give up flight? Scientists have now confirmed a long-suspected answer: It would rather swim.

Being both a diver and a flyer is costly and inefficient, suggests a new study of murres, penguinlike seabirds that both swim and retain command of the air. Murres "are awful flyers," says graduate student Kyle Elliott of the University of Manitoba in Winnipeg, Canada, an author of the new paper published online this week in the Proceedings of the National Academy of Sciences. "They beat their wings really, really fast, and they're horrible at landing."

Thick-billed murres (Uria lomvia, inset), which nest on cliffs in Alaska, Canada, and other northerly sites, expend more energy per minute of flight than any other bird, the team found. On the wing, murres burn energy at 31 times their rate at rest, the highest known ratio in a bird. In water, they're more efficient than many birds, but expend more energy while diving when compared with penguins. That suggests that by giving up flight, penguins improved their diving prowess.

## By the Numbers

30th Anniversary of the discovery of the AIDS virus. Unveiled in Science on 20 May 1983, the discovery earned Institut Pasteur researchers Luc Montagnier and Françoise Barré-Sinoussi Nobel prizes.

25 Cubic kilometers of ground water pumped by the United States each year from 2000 to 2008, according to the U.S. Geological Survey. The average rate over the past century was 9.2.

194,000 Number of signatures on a change.org petition to drop charges against Florida teen Kiera Wilmot, who was arrested on 1 May for causing a small explosion at her school during a science experiment. Charges were dropped on 15 May.

## Was the Downfall of Louis XVI in His DNA?

In 1793, as the French Revolution reached its height, King Louis XVI and his wife Marie Antoinette met their fates at the guillotine. According to legend, a witness soaked up the king's blood in a handkerchief and stored the cloth in an engraved gourd.

Turns out, the legend was true. DNA from that gourd shows not only that the blood was the king's but also that Louis carried genetic risk factors for diabetes, obesity, and bipolar disorder, reported Carles Lalueza-Fox of the Institute of Evolutionary Biology in Barcelona, Spain, at the Biology of Genomes meeting earlier this month in Cold Spring Harbor, New York. Some historians have blamed Louis's downfall on his indecisiveness, but the genome suggests that the king's inept rule might have had a biological basis, Lalueza-Fox said.

There was scant human DNA in the gourd; most of the DNA came from the squash or from bacteria associated with rotting vegetables. At first, all Lalueza-Fox could say was that the human DNA was from a blue-eyed European male. But the Y chromosome proved to match one obtained from the mummified head of the king's direct ancestor, Henry IV of France. That head has its own odd history: Lost after looters ransacked royal graves during the French Revolution, it was recovered and identified in 2010.

The findings are a bellwether, says Jeffrey Kidd, a population geneticist at the University of Michigan, Ann Arbor. "The combination of these approaches to recover information from small amounts of degraded DNA is going to open up all sorts of fascinating history stories," he says.

The OSIRIS-REx mission to return a bit of asteroid to Earth got NASA's final approval last week. Set to launch in 2016, the mission will return 60 grams of 490-meter-diameter Bennu in 2023. That puts the $1 billion robotic mission ahead of NASA's unfunded plan for a robotic spacecraft that would snag a 500-tonne asteroid and haul it to Earth orbit no earlier than 2022 for astronauts to study. ## ScienceLIVE Join us on Thursday, 30 May, at 3 p.m. EDT for a chat on the ethics of studying chimps in captivity. http://scim.ag/science-live 3. # Hubs Aim to Reinvent DOE Research Culture 1. Adrian Cho The U.S. Department of Energy has funded a series of energy innovation hubs to tackle big energy challenges from start to finish. But their future is uncertain. Eight nuclear engineers sit in high-backed leather chairs, their laptop computers perched on sleek wood consoles. The lights are so low that the corners of the room fade to black. Up front, a roomwide video screen shows a half-dozen other researchers from locations around the country. A cryptic conversation rattles on: "Rod, we have to be careful. Right now the Cobra to de Novo isn't even using DTK." Welcome to the Consortium for Advanced Simulation of Light Water Reactors (CASL) at Oak Ridge National Laboratory in Tennessee, one of five "energy innovation hubs" launched by the Department of Energy (DOE) to tackle tough problems. The researchers participating in the virtual meeting at CASL are scrolling through a vast list of tasks as they integrate different computer programs for simulating the inner workings of nuclear reactors so that utilities can run them more efficiently. The brainchildren of Steven Chu, the Nobel Prize–winning physicist who stepped down last month as secretary of energy, the hubs are a bold experiment in how DOE does research. Modeled after the Manhattan Project that built the atomic bomb and the famed Bell Labs, the hubs aim to make the sprawling and notoriously bureaucratic agency more nimble and responsive. Each would focus on a single problem, assemble "under one roof" all the scientists and engineers needed to tackle everything from basic research through technological development, and take a free-wheeling approach to hammer out a solution as fast as possible. In 2009, as soon as he became energy secretary, Chu announced plans to create eight hubs. To date, DOE has launched five, funding each for$122 million over 5 years with the possibility of a 5-year renewal. In 2010, in addition to CASL, it established hubs that focus on generating fuel from sunlight through artificial photosynthesis and reducing energy consumption in buildings. In recent months, DOE has launched hubs to create far better batteries and to head off shortages of materials. And DOE's proposed budget for 2014 requests money for a sixth hub on electrical systems such as the power grid.

The problem-oriented approach draws plaudits from researchers and some policymakers in Washington, D.C. "The hub is exactly what DOE should be doing," says Charles Dismukes, a physical chemist at Rutgers University, Busch Campus, in Piscataway, New Jersey. A Republican Senate staffer agrees: "I think you're going to see an expansion of these, and the traditional [DOE research] program may stagnate as a result."

Before that can happen, however, the hubs will have to prove their worth at a time when budgets are likely to be tight. Evaluating them will not be easy, in part because they widely vary in the ways that they are organized and the types of problems that they are tackling. For example, only one of the five strives to be a physical center of activity; the rest are widely distributed collaborations. In fact, the hubs vary so much that it's difficult to say exactly what a hub is. And some see a risk that, now that Chu is gone, the hubs could be subsumed into the department's existing bureaucracy and their independence compromised.

To understand what a hub is supposed to be, it helps to understand how DOE is structured. Sometimes called the Department of Everything, DOE has a $24.4 billion annual budget and comprises a dozen different offices and agencies, such as the National Nuclear Security Administration, which safeguards the United States' nuclear weapons, and the Office of Energy Efficiency and Renewable Energy (EERE), which develops clean energy technologies. An office may be divided into programs, such as the$1.6 billion Basic Energy Sciences (BES) program within the $4.7 billion Office of Science. DOE has a reputation for being badly "stovepiped," meaning that the various offices and programs poorly communicate with one another. For example, in theory the BES program should yield breakthroughs in basic research that the EERE program then develops through its applied research. In practice, "BES does its thing and then they throw it over the transom and hopefully it hits somebody at EERE in the head," says William Madia, vice president at Stanford University for DOE's SLAC National Accelerator Laboratory in Menlo Park, California, a national lab mainly supported by BES. The hubs aim to break down the barriers between basic and applied research. Chu shaped the concept by calling on his experience at Bell Labs, the research wing of the AT&T phone company that from the 1920s through the 1990s produced technologies ranging from the transistor to the laser. Chu did his Nobel Prize–winning work there, and he says the lab succeeded because it let scientists and engineers quickly hash things out for themselves. "The managing scientists and engineers were the bosses," Chu says. "Unlike a 3-year grant where you write a proposal and it takes a year to get funded, at Bell Labs if I had an idea I'd go to my boss or my boss's boss and get a yes or no in days or weeks." As at Bell Labs, a hub is supposed to bring together all the people and resources needed to perform everything from the basic research and development to demonstration and deployment of a prototype solution. "The distinctive signature of the hub is that it goes from basic research all the way through to deployment all under one roof," Madia says. "You can't find that kind of activity when you look at the DOE stovepipes." The target areas for the hubs have been chosen by top DOE officials, including Chu himself. Teams then submitted proposals and competed for each hub, with the proposal detailing a team's approach to the problem. ## The archetypal hub No hub embodies the center-of-action concept used at Bell Labs more closely than the Joint Center for Artificial Photosynthesis (JCAP). Headquartered at the California Institute of Technology (Caltech) in Pasadena and funded by the BES program, JCAP (pronounced J-cap) aims to create a technology that could ease both the world's looming energy crunch and climate change caused by burning fossil fuels. "We want to have something that you can hold in your hand that will produce fuel from sunlight in a way that humans haven't done before—with no wires and no microbes," says Nathan Lewis, a chemist at Caltech and JCAP's founding director and chief scientist. The basic idea of "solar fuels" isn't new. Plants store solar energy in sugars through photosynthesis, so a refinery that generates ethanol from corn creates fuel from sunlight. JCAP researchers aim for something more direct—using solar energy to split water and generate combustible hydrogen gas. That can be done in the lab by, for example, using a wafer of silicon plated with platinum on one side and iridium on the other. Using solar energy captured by the silicon, the iridium catalyzes the breakup water into oxygen molecules, hydrogen ions, and electrons, while the platinum combines the electrons and ions into hydrogen molecules. Other approaches use different catalysts. But none of those approaches is ready for the real world. For a solar-fuels industry to flourish, its core technology must be efficient, durable, and cheap. No existing technique nails all three requirements, says Carl Koval, an electrochemist at Caltech and JCAP's director. The platinum and iridium scheme is efficient and robust, for example, but iridium is rare and expensive. JCAP's goal is a cheap, durable cell that is 10 times as efficient as photosynthesis. As the hub concept stipulates, JCAP researchers grapple with every aspect of the problem, breaking it into eight distinct projects. Interconnected groups strive to identify new catalysts and light-capturing materials, make sure they'll work together, integrate them into structures sculpted on the nanometer-scale, and design the macroscopic cell. Some of JCAP's goals are wildly ambitious. Researchers plan to characterize a million catalysts per day using a modified inkjet printer to print tiny dollops of the materials on glass slides. That would be more catalysts in 1 day than have been characterized in history, Lewis says. Perhaps most striking is the enthusiasm with which JCAP officials embrace the "one roof" concept. JCAP leaders say that their biggest organizational challenge is to prevent JCAP from becoming just another university research center. William Royea, a chemist and JCAP's assistant director for strategy and communications, characterizes such a center as "a confederation of research projects in which everybody goes off and does whatever they want." JCAP leaders see physical proximity as the best means to avoid that loss of focus. In particular, JCAP leaders want to prevent scientists from viewing the hub as just a source of funding for work that they're already doing in their own labs. To keep researchers focused on building the device, JCAP officials insist that they work in JCAP's cozy building. "If you're on JCAP, you're here every day. You're in the building," Lewis says. (JCAP actually has two buildings, with a northern branch at Lawrence Berkeley National Laboratory in California. However, its leaders note that Bell Labs also had multiple campuses.) The flow of money also follows the Bell Labs' model. Funding goes not to individual principal investigators but to the eight project leaders who distribute it as they see fit. ## Virtual centers Although JCAP strives to be a center of activity, the other hubs are extended collaborations. For example, CASL comprises 10 institutions including DOE's Idaho National Laboratory in Idaho Falls; the Electric Power Research Institute (EPRI) in Palo Alto, California; and Westinghouse Electric Company. Most researchers visit Oak Ridge only every other month. "I love living here," says Douglas Kothe, a nuclear engineer at Oak Ridge who leads CASL. "But a lot of people don't and a lot of people won't. So our one-roof model is to aggressively deploy virtual-collaboration technology." That's fine, observers say, because the cost of moving people and equipment could easily consume all the money that the hub receives from DOE. The real issue, they say, is whether a hub tackles the right kind of problem—one big enough to require a hub's resources, but not so big that it can't be solved in 5 years. By all accounts, CASL has found just such a problem: simulating the inner workings of the nuclear reactors in service today. Funded through DOE's$720 million Office of Nuclear Energy, CASL is an attempt to play catch-up. The nuclear industry pioneered the use of simulations, Kothe says. But the United States has not broken ground for a new nuclear power plant since 1977, and as the nuclear industry stagnated, so did the simulations. "This field is a couple of decades behind" the automotive and aerospace industries in using simulations, Kothe says.

Still, such simulations are crucial for demonstrating to the Nuclear Regulatory Commission (NRC) that any changes to a reactor's design or operations will be safe. The 104 U.S. reactors now run at 92% of capacity, up from less than 80% 20 years ago, says John Gaertner, a nuclear engineer and CASL member from EPRI. To improve efficiency and reduce costs, utilities would like to further increase power levels, the length of fuel cycles, and the extent to which fuel is depleted, or "burn-up." Current simulations largely rely on data from reactor tests to make semiempirical predictions, says Daniel Ingersoll, a nuclear engineer with NuScale Power in Portland, Oregon, who does not work on CASL. That limits how much plant owners can change designs and operations, he says.

CASL aims to produce 3D simulations that more fully capture the underlying physics and chemistry, says Paul Turinsky, a nuclear engineer from North Carolina State University in Raleigh and CASL's chief scientist. Current 2D simulations track the flow of cooling water around the fuel rods in the reactor's core at hundreds of points; CASL's simulations will track it at a billion points. Turinsky says that CASL's simulations will also encompass the tricky interactions between the radiation emanating from the fuel rods, the flow and heating of the water around the rods, and the effects of the radiation on materials such as the rods' metal cladding.

CASL is leading the other hubs in generating results, observers say. To ensure that their work is practical, CASL researchers are also analyzing operational challenges facing reactors. One is the buildup of deposits known as CRUD—for their historical name, Chalk River Unidentified Deposits—on the fuel rods, which can distort the rods' power output. CASL researchers have already predicted a CRUD pattern that was later detected on rods. "We consider that a major advance," says William Martin, a nuclear engineer and CASL member from the University of Michigan, Ann Arbor.

CASL researchers hope that industry will use their simulations to improve the design of fuel assemblies and fuel cycles. Developing the simulations is too costly for industry alone, says Zeses Karoutas, a nuclear engineer and CASL member with Westinghouse in Columbia. "Industry can't put together the kind of funding that's needed," he says. "The only way to do it is to leverage the national labs and the universities."

## Soft focus

Some hubs are not focusing on a specific problem, an approach that has created some controversy. The Energy Efficient Buildings (EEB) hub in Philadelphia, Pennsylvania, which is mainly funded by EERE, aims to improve energy efficiency in area buildings by 20% by 2020. Buildings soak up 40% of the energy used in the United States, says James Freihaut, a fuel scientist at Pennsylvania State University (Penn State), University Park, and chief scientist for EEB. So if implemented nationwide, such an improvement would save massive amounts of energy.

Buildings have become only marginally more efficient in recent decades, even though the efficiency of subsystems such as heating, air conditioning, lighting, ventilation, and electrical power have improved by larger amounts, Freihaut says. That disparity arises because builders do not consider how the various subsystems will interact, he says. "We're trying to transform the building industry as a whole into a system provider," he says.

To do so, EEB researchers are developing computer modeling tools to predict how different combinations of specific subsystems will interact. The need for such tools became apparent when EEB researchers went to retrofit their current headquarters, an old building in Philadelphia's Navy Yard, Freihaut says. Three different consulting firms gave entirely different assessments of what needed to be done, he says.

Using their own building, EEB researchers are also studying how many measurements of temperature, humidity, air flow, electricity use, and other factors are needed for a building to be "self-aware" enough optimize its energy consumption. With foreseeable advances in materials, such as one-way membranes to draw moisture out of a building or building materials whose capacity to hold heat changes with temperature, energy use could drop by between 30% and 50%, Freihaut predicts.

However, improving building efficiency is not a single well-defined technological problem, but rather a raft of various technological, economic, and regulatory issues. For example, the Philadelphia City Council drew upon one of EEB's studies for an ordinance that requires the owners of commercial buildings bigger than 4700 square meters to publicly report a building's water and energy consumption. The law, passed in June 2012, is supposed to give tenants a clearer idea of their energy costs and owners an incentive to make buildings more efficient.

EEB's work is focused less on developing new technologies and more on persuading builders to adopt ones that already exist. "We actually don't want to be too much on the leading edge because building owners are naturally conservative," says Laurie Actman, an engineer at Penn State and deputy director of EEB.

All that work may be worthy, but some Washington insiders question whether it requires a \$122 million hub. In fact, multiple sources on Capitol Hill say that EEB's future is uncertain. "We have serious concerns about the building hub," says a staffer for the Democratic majority in the Senate. "If this doesn't turn around in the next few months in terms of clarifying what we're getting for our investment, you may see some action."

The same issue of focus has come up with regard to one of the two latest hubs. One of them seems to neatly fit the hub model in having a crisply defined technological goal. In November, researchers at Argonne National Laboratory in Illinois won the competition for a hub to develop far better batteries. The Joint Center for Energy Storage Research (JCESR) aims to produce within 5 years a battery that can hold five times as much energy as a standard lithium ion battery and can be made for one-fifth the cost.

In contrast, the Critical Materials Institute (CMI) at Ames Laboratory in Iowa, which launched in January, will tackle the complex question of how to ease shortages of vital elements such as the one that arose in 2009 when China threatened to stop exporting neodymium, europium, and other rare earth metals. CMI researchers will take a four-pronged approach, doing the basic materials science to find ways of replacing or reducing the use of key materials, exploring better ways to extract materials from ore, pursuing advanced recycling, and trying to predict shortages.

In doing so, however, CMI researchers seek to solve not a single technological challenge, but rather to meet a variety of challenges as they arise. "What we are seeking to develop is a resource—the SWAT team for materials shortages," says Alexander King, a materials scientist and director of Ames lab and CMI. That description raises some eyebrows in Washington. "The original notion of a laser focus on a specific problem that you'd know whether you'd solved it or not is totally unclear on that one," says one Republican House of Representatives staffer.

## Life after Chu

It's too early to tell whether each hub will reach its technological goal. And the standard will vary. For example, for JCAP to claim success, researchers must simply come up with a practical prototype. And some say that's a long shot. "It will only work if the science is there, and it's not there yet," says Richard Eisenberg, a chemist at the University of Rochester in New York.

In contrast, CASL's success will depend on whether NRC approves its simulations for use in licensing applications. CASL's work so far is impressive, says Jennifer Uhle, deputy director for reactor safety programs in NRC's Office of Nuclear Reactor Regulation. However, approval requires "validating" the simulations' accuracy with reactor data, she says. Given the level of detail in the simulations, data for such validation may be hard to get right away, Uhle cautions. "You can't measure the flow [of water in a reactor] at a billion points without disrupting the flow you're trying to measure," she says.

In spite of the uncertainties, the hubs appear to enjoy support in both houses of Congress. Compared with DOE's traditional research program, the hubs' problem-oriented approach makes it easier for legislators to see what they're getting for their money, says the Democratic Senate staffer. Still, the staffer cautions, to prove their worth the hubs have to produce results that couldn't be achieved otherwise.

The view from the Republican-controlled House is more circumspect. Anxious to protect DOE's basic research programs, some Republican legislators worry that the hubs may duplicate research within DOE and elsewhere. For example, the Republican House staffer says, the federal government already funds 39 initiatives on battery research, including 11 within DOE.

At the same time, House Republicans seem willing to give the hubs a chance. "If you're going to start these things, you should at least finish the first 5 years and look at the metrics and see how these things have succeeded," the staffer says.

Ironically, the biggest threat to the hubs could come from within DOE. The hubs are supposed to break with DOE's traditional way of structuring research. To allow researchers to react quickly to promising leads, the hubs are supposed to be managed with a "light federal touch," says Alexander Larzelere, DOE's program manager for CASL in Washington, D.C. To maintain that autonomy, Larzelere is DOE's only point of contact for CASL, and he says he must make a concerted effort to fend off other bureaucrats. "I spend most of my day trying to keep people from mucking with the hub," he says.

However, that streamlined arrangement means CASL answers to only DOE's Office of Nuclear Energy. So it runs counter to the idea that the hubs should span the stovepipes, says Stanford's Madia. In fact, people have begun to talk about the hubs as belonging to one or another office, he says, so that the batteries hub is an Office of Science hub and the materials hub is an EERE hub.

Such a mindset, Madia says, threatens to obscure a hub's mission to span the spectrum of research, development, demonstration, and deployment of a technology. "If it's going to work, you need a healthy amount of each of these four pieces," he says. "If you get it out of balance, you're just replicating what DOE is already doing."

In fact, some researchers argue that the independence of the hubs is undermined by DOE's failure to follow through on all aspects of the concept. The hubs were supposed to answer to a hubs board, and a hub "champion" within DOE would stick up for them personally, says Paul Hallacher, a political scientist and director of EEB. But those things never materialized, Hallacher says. "There is no DOE hubs program," he says. "There are merely five hubs lodged within different offices." But others argue that such a board would only add another level of bureaucracy to the system.

With no concrete mechanism to guarantee that the hubs maintain just the right amount of autonomy, the fate of the hubs may well depend on how strongly they are embraced by Chu's successor. On 4 March, the Obama administration nominated Ernest Moniz, a nuclear physicist from the Massachusetts Institute of Technology in Cambridge who served as undersecretary in DOE from 1997 to 2001, to be the next energy secretary.

Hubs' proponents are optimistic that Moniz, who was unanimously confirmed last week by the U.S. Senate, will see the value of their work. He's certainly familiar with the concept, having chaired CASL's board of directors from the hub's inception until last year. Still, observers say, Moniz will have lots of other issues to attend to and may have initiatives of his own for which he'd rather push now that he is in office.

Even if Moniz does embrace the hubs' concept, his first task may be to define exactly what a hub is.

4. Ecology

# Are Isle Royale's Wolves Chasing Extinction?

1. Christine Mlot*

Wolves in an iconic predator-prey study are not producing pups, leaving scientists to confront a genetic rescue—or the project's demise.

Since his graduate student days in 1971, Rolf Peterson has spent a few nights of every summer camped within earshot of wolf packs on Isle Royale, Michigan, in the northwestern corner of Lake Superior. It may be as early as the end of June that he hears the sound he's waiting for: high-pitched yips that stand out from the long, sonorous howls of adult wolves. The calls herald a new generation of pups joining the island's storied wolf population. For 40 years without fail, Peterson and his colleagues have heard those yips.

Until last summer. For the first time, the wildlife ecologist at Michigan Technological University in Houghton heard no yips in 2012, and failed to spot pups during the official aerial population count in January 2013. The lack of reproduction means that 2012 will likely go down as the beginning of the end of Isle Royale's wolves. The January count put them at their lowest number ever—only eight closely related individuals, down one from last year. The Michigan Tech team is on the island now and will listen intently for pups this summer, but Peterson believes that inbreeding's pernicious effects have doomed the wolves. "It's over," he says. "It's just a matter of watching it wind down."

The surprise may be that the inbred population on the 544-square-kilometer isle has hung on this long, more than 6 decades after it was established by two or three curious wolves from nearby Canada. One school of thought has maintained that this chance natural experiment should run its course even if that means extinction, followed by a transfusion of fresh wolves to control the moose population on the rugged island, which is a U.S. National Park. But some researchers argue that the study's value is so great and the current wolves so integral to the island that they warrant a "genetic rescue," by importing other wild wolves soon.

After discussions with geneticists, Peterson now leans toward this option as the "most beneficial, giving the best scientific return." But the fate of the wolves rests with the park service.

## One for the books

The story is a staple of biology textbooks. Moose arrived on Isle Royale in the early 1900s, probably by swimming the 24 kilometers from the Ontario shore. Their numbers exploded on the predator-free island, and their browsing took a toll on the boreal forest. Then in 1949, a breeding pair of wolves crossed the frozen stretch of lake and began preying on the moose. The two populations began their scientific careers in 1959, when wildlife biologist Durward Allen of Purdue University and graduate student L. David Mech recorded the first numbers—20 wolves and about 500 moose—in what has become the world's longest running predator-prey study and one of science's most famous data sets.

The study has borne out some of ecology's fundamental tenets. It provided the first indisputable evidence that wolves hunt old and infirm moose or calves while leaving healthy adults alone. It was one of the first studies to show top-down control of a terrestrial food chain, by connecting wolf predation to the health of trees as seen in tree rings (Science, 2 December 1994, p. 1555). "Trees grew better when wolves were high and moose were low," Peterson says.

Since the pioneer wolves padded across an ice bridge to the island, the tale of Isle Royale has testified to the power of random events. "The significance of rare, unpredictable events is enormous," Peterson says, and often only understood in the long term. For example, in the 1980s the wolf population crashed from its peak of 50 to a mere dozen (see timeline, p. 920). Years later, researchers found out why, detecting signs of deadly canine parvovirus in the wolves (Science, 27 August 1993, p. 1115). Even later, Peterson learned how parvo was likely brought to the island: A Minnesota veterinarian reported treating a parvo-infected dog that illegally visited the island on 4 July 1981. By 1990, the virus apparently burned itself out and disappeared from the island.

It's not just the wolves that have yielded scientific bounty: The moose, too, have been a research bonanza. Researchers and volunteers have packed out bones from close to 5000 moose carcasses, resulting in the world's largest collection. Together with bones from about 50 wolves, these remains have yielded insights on topics including forest health and moose arthritis.

For example, while teaching a dissection class, Peterson noticed that the club-sized lower leg bone of moose from the mainland seemed larger than what he was used to in Isle Royale specimens. His team has since shown that the size difference is significant and in a paper in press in the journal Alces will report that male Isle Royale moose have smaller antlers, too. In just a century on the island, moose have downsized to become among the smallest in the world. Thus, they are a classic case of another key biological insight: Large mammals shrink on islands, as did the miniature hippos and elephants that lived on Mediterranean islands during the Pleistocene. "On islands, big things get smaller," says evolutionary biologist Shripad Tuljapurkar of Stanford University in Palo Alto, California. The Isle Royale findings, he says, "provide good evidence that the island rule applies."

## Inbreeding's insidious effects

Now that the wolf population has sunk to an all-time low, with just two remnant packs instead of the historical three or four, this natural experiment in population biology and island biogeography is turning into a grim portrait of inbreeding depression: the reduced biological fitness that plagues tiny populations.

At least half of the eight wolves counted in January are female, according to DNA tests of scat, but the researchers detected less courting and mating than usual during their winter survey. The lack of reproduction may be because wild wolves typically avoid mating with close kin—and there are no other options on Isle Royale. Or, the wolves are mating but infertile because of genetic anomalies from inbreeding, or their offspring may not be viable.

In any case, it's clear that the wolves are racking up more and more physical abnormalities, probably from inbreeding. A 2009 paper in Biological Conservation reported that 58% of examined wolves had congenital spinal deformities, compared with only 1% of wolves in other populations. The abnormalities appear widespread—they turned up in all 12 wolves necropsied recently—but apparently are not crippling, Peterson says.

Other observations bolster the argument that inbreeding is eroding the population's fitness. Researchers have noted wolves with one opaque, perhaps blind, eye. Also, an apparently healthy female died in her den in 2009 after delivering one pup, with her remaining seven pups dying in utero. That had never been documented before in a wild wolf and may have ultimately stemmed from inbreeding, Peterson says.

As dark as the outlook looks for the wolves, Isle Royale also offers compelling evidence of how to revive an inbred population. In 1997, in another chance event unbeknownst at the time to researchers, a large male wolf from Ontario crossed the ice bridge to the island. In 1998, the scientists spotted a striking animal—which project co-leader and Michigan Tech population biologist John Vucetich later nicknamed "old gray guy"—that became whiter as he aged, something not seen before in Isle Royale wolves. But his provenance didn't become clear until after 2007, when Jennifer Adams, then a postdoctoral researcher at Michigan Tech and now at the University of Idaho in Moscow, extracted DNA from stores of frozen wolf blood, bone, and scat and analyzed it for key microsatellite markers to identify individual wolves.

The wolf DNA markers were rigged to fluoresce when exposed to a laser and recorded by software as distinctive peaks. As Adams ran the results for a marker on the Y chromosome to identify males, she found a common peak representing one characteristic Y chromosome. As she ran the data for later years, a second peak suddenly appeared, representing a different Y chromosome marker. By the time she got to the 2003 samples, the first marker type had disappeared. When she constructed a family tree based on the genetic markers, the second type markers all traced back to one wolf.

Peterson and Vucetich went back to their field notes on the scat sample that had yielded the new Y chromosome: They had observed the old gray guy defecate at the site of a winter moose kill and had taken a sample. The new Y chromosome marker was independent corroboration of what researchers had noted in the field—the gray guy had taken over one pack as the new breeder.

Breed he did. After mating with a female and later with his own daughter, the old gray guy sired 34 offspring and genetically took over Isle Royale before his death in 2006. After a single generation, 56% of the genes in the population were his. His Y chromosome is now the only one present in the population. "Such a dramatic selective event influencing the whole genome has never been documented in a wild population before, as far as I know," says Arizona State University, Tempe, population geneticist Philip Hedrick, one of Adam's co-authors on a 2011 report on the phenomenon in the Proceedings of the Royal Society B.

Old gray guy's appearance in 1997 "saved the population for another 10 to 15 years," Peterson says. As wolf numbers grew, moose numbers fell, reinvigorating vegetation. "He had an impact on the entire forest of Isle Royale," Peterson says. The immigrant also opened up a new research vein. University of California, Los Angeles, evolutionary biologist Robert Wayne and colleagues are now sequencing the genome of Isle Royale wolves before and after the old gray guy's arrival, to see how inbreeding affects genome architecture and to compare mutations with those of outbred wolves.

Old gray guy's new genes weren't a cure-all, however. With the wolves dwindling once again, the population clearly could use another infusion of new blood.

But the odds are slim that more Canadian wolves will find their way onto Isle Royale. Temperatures in the region are rising with the changing climate, and the formation of winter ice bridges has become a once-a-decade event, instead of once every two to three winters as in the 1960s. Recent hot summers also seemed to be affecting the cold-adapted moose, which were down to about 385 in 2007. With wolves on the wane, however, moose are now waxing, from about 750 in 2012 to 975 at the start of 2013.

## What to do?

Last winter, the researchers and the park service solicited input from geneticists about the wolves' decline. But opinion on the path forward is divided. Citing successful genetic rescues of other populations, such as the Florida panther (Science, 24 September 2010, p. 1641), Hedrick and others advocate a similar operation on Isle Royale. Their argument rests on the wolves' importance to the ecosystem and their influential scientific legacy. "It's so incredibly rare to have such a long-term data set," says conservation geneticist Lisette Waits of the University of Idaho. Advocates also note that the current wolves have cultural knowledge of the island. Although other populations hunt moose, Isle Royale is distinctive in that a single predator basically depends on a single prey. The population may not be genetically different from Ontario's Canis lupus, but "I don't think you should say they are just like every other population," Hedrick says.

Vucetich is open to a genetic rescue and the lessons it could offer to other populations on the brink. Yet, he says there's still a chance—a very small one—that the wolf population can come back on its own. "Isle Royale wolves are in the business of surprising us," he says. Mech, now with the U.S. Geological Survey, notes that the recent moose decline could have delayed wolf breeding. With last winter's moose calf boom, pups could still arrive in the next few years.

The park service generally takes a hands-off approach in wilderness areas, but it's giving Isle Royale special scrutiny. The agency has assembled a team of national policy experts, local wildlife managers, and others to review the plight of the wolves in the context of how to treat the species in national parks as a whole. Options under consideration are to do nothing, bring in new wolves as soon as possible, or reintroduce wolves once the existing population dies off, which could happen in the next 5 years. The researchers are adamant that wolves are integral to Isle Royale's ecosystem. "As long as there are moose on Isle Royale, there should be wolves," Vucetich says.

Climate change is also a big part of the discussion, says Isle Royale park Superintendent Phyllis Green, who expects the team to recommend a course of action by fall. At that point, a public consultation will kick in, although anyone can weigh in now by sending comments to ISRO_Wildlife{at}nps.gov.

The park service decision will determine the fate of only a few animals on a remote island. But given the increasing number of isolated wildlife populations, Green says, this is "a national decision that will affect national policy."

In the meantime, researchers and park visitors alike remain on watch. Earlier this month, volunteers on the project were lucky enough to spot three wolves hanging out on a frozen bay. The threesome probably was one of the packs, Peterson says—which means that the female isn't curled up in a den with weeks-old pups. So the lucky sighting may bode ill for the wolves. Whether these wolves blink out, revive, or face another unpredictable game-changing event, observers on and off the island will be watching.

• * Christine Mlot is a Wisconsin-based writer.