News this Week

Science  15 Jun 2012:
Vol. 336, Issue 6087, pp. 1364
  1. Around the World

    1 - Washington, D.C.
    NASA Rover Will Contaminate Mars Samples
    2 - Geneva, Switzerland
    WHO Warns of Drug-Resistant Gonorrhea
    3 - Queensland, Australia
    Fears of Damage to Great Barrier Reef Delay Mine
    4 - London
    Bioethics Council: Mitochondrial Disease Therapy Is Ethical
    5 - Sacramento, California
    California Rejects Tobacco Tax
    6 - Paris
    French Research Unions Protest Funding Plan
    7 - Washington, D.C.
    NASA Axes Mission to Study Black Holes, Neutron Stars

    Washington, D.C.

    NASA Rover Will Contaminate Mars Samples

    The Curiosity rover will definitely find evidence of an advanced civilization if it lands safely on Mars. That's because any rock samples the rover drills will be contaminated with bits of Teflon from the rover's machinery, NASA announced during a press teleconference on 11 June.

    CREDIT: NASA

    Curiosity's $2.5 billion mission includes searching for the carbon-containing molecular remains of any life that inhabited ancient Mars. The rover will use its Sample Analysis at Mars (SAM) instrumentation to analyze samples. To extract the rock samples, the rover will bang a drill bit into the rock—which will also rub off bits of Teflon from seals in the drill assembly. The Teflon—which is two-thirds carbon—can become mixed in with the sample, which will be vaporized for analysis.

    The team is guardedly upbeat that it can overcome the problem: Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland, says team members can minimize the amount of Teflon getting into the analytical system by altering operation of the drill. Once in SAM, Mahaffy says, the compounds being analyzed are heated to a temperature at which Teflon decomposes, producing mostly small, easily identified compounds of carbon and fluorine. http://scim.ag/Teflonrover

    Geneva, Switzerland

    WHO Warns of Drug-Resistant Gonorrhea

    CREDIT: CDC/M. S. FERGUSON

    Last week, the World Health Organization (WHO) warned that gonorrhea, which infects 106 million people in the world each year, could soon become untreatable. In its Global action plan to control the spread and impact of antimicrobial resistance in Neisseria gonorrhoea, released on 6 June, the public health arm of the United Nations sounds a dire note. “The loss of effective and readily available treatment options will lead to significant increases in morbidity and mortality,” the authors write.

    Gonorrhea, if left untreated, can lead to infertility in men and women and increases the risk of contracting and transmitting HIV. It can also cause blindness in children born to infected women. The gonorrhea pathogen is now resistant to many common antibiotics such as penicillin and tetracyclines; only one class of antibiotics, called cephalosporins, has remained effective. But in the last few years, Australia, Sweden, Japan, the United Kingdom, and other countries have reported cases of resistance to cephalosporins.

    WHO is pushing for better surveillance of resistant strains, and the plan also calls for stricter prescription policies and more research into alternative treatment regimens for gonococcal infections.

    Queensland, Australia

    Fears of Damage to Great Barrier Reef Delay Mine

    CREDIT: ISTOCKPHOTO.COM; TONY ASHBY/AFP/GETTYIMAGES

    Citing concerns that a $6.4 billion coal mine planned in Queensland would cause significant damage to Australia's Great Barrier Reef, on 5 June Australia's federal minister for sustainability and environment, Tony Burke, halted the environmental clearances granted to the mine.

    The week before, on 29 May, the Queensland government had approved the GVK-Hancock Coal mine, which is co-owned by the Indian infrastructure conglomerate GVK and billionaire miner Gina Rinehart (inset), the world's richest woman.

    However, Burke said he could not sign off on the Queensland government's conditional approval, calling it “shambolic” and dangerously deficient. The mine and a planned rail link to the port, he said, could pose problems for the long-term conservation of the reef.

    London

    Bioethics Council: Mitochondrial Disease Therapy Is Ethical

    In vitro fertilization techniques that could allow women with mitochondrial disease to bear healthy, genetically related children are ethical, provided the techniques prove to be safe, according to a report released on 11 June by the Nuffield Council on Bioethics. Mitochondria, which are inherited only through the mother, are organelles that provide cells with energy. They carry their own genome, and mutations in mitochondrial genes can lead to a range of symptoms, including blindness, deafness, dementia, and muscle disorders.

    Research groups have experimented with ways to transfer the genetic material from an egg with faulty mitochondria into a healthy egg. But the technique raises ethical questions: Any resulting child would carry genetic material from the mitochondrial donor. And any female child would pass the donated mitochondrial genome to her children. The Nuffield Council said that, provided the technique proves to be safe and effective, it would be ethical for families to use it. The techniques are not currently allowed in the United Kingdom, which prohibits any IVF treatment techniques in which sperm or eggs that have had any of their DNA altered are implanted in a woman's body. http://scim.ag/mitoethics

    Sacramento, California

    California Rejects Tobacco Tax

    Voters in California narrowly rejected a ballot measure on 5 June that would have increased the state tobacco tax by $1 a pack to raise an estimated $441 million a year for research on cancer and other tobacco-related illnesses.

    Proposition 29, defeated by a vote of 50.8% to 49.2%, would have made California one of the world's largest funders of cancer research. Supporters, led by the American Cancer Society and the Lance Armstrong Foundation, argued that the measure would also save thousands of lives by discouraging smoking.

    Tobacco companies and other opponents mounted a campaign against the measure and raised nearly $47 million to defeat it, including $27.5 million from tobacco company Philip Morris. Television and radio ads portrayed the measure as creating a burdensome bureaucracy that would do nothing to help the state's budget woes.

    Paris

    French Research Unions Protest Funding Plan

    On 6 June, members of the French scientific community announced the launch of legal action against the country's new government, hoping to prevent the development of national excellence clusters—which apparently offend the researchers' sense of égalité.

    France's former president, Nicolas Sarkozy, launched the €7.7 billion Excellence Initiatives (IdEx) program in 2010 as part of a €21.9 billion boost to research and higher education. Sarkozy's government selected 8 clusters of universities and institutions to receive an IdEx award.

    In a joint statement dated 14 May, the French National Trade Union of Scientific Researchers (SNCS-FSU) and the National Union of Higher Education Professors (SNESUP-FSU) said that because the IdEx program concentrates the resources of the national financial boost on a selected number of clusters, it threatens core principles—equality, democracy, and a collegial administration—dear to research and higher education in the nation.

    The new minister for higher education and research, Geneviève Fioraso, has not yet responded to the legal actions, but told national newspaper Le Monde that the government would “reexamine the IdEx [projects] from every angle.”

    http://scim.ag/IdExprog

    Washington, D.C.

    NASA Axes Mission to Study Black Holes, Neutron Stars

    CREDIT: NASA

    NASA has cancelled a mission to study the warping of space around black holes and map the structure of magnetic fields around neutron stars. The Gravity and Extreme Magnetism Small Explorer (GEMS), scheduled to be launched in 2014, was supposed to cost no more than $119 million. But after independent external reviews of the project found that the final costs were likely to exceed that cap by 20% to 30%, NASA pulled the plug on the project.

    The agency has already spent $37 million on the design of instruments for the mission; it will cost another $13 million to close out the project. “One of the major contributors of the increased cost was that the technology development was more difficult and took longer than they [the mission planners] had originally estimated,” Paul Hertz, head of NASA's astrophysics division, said, announcing the project's cancellation 7 June. GEMS was initiated under a cost-cap competition, Hertz says. “As such, the cost cap is a very important aspect of the project.”

  2. Random Sample

    Noted

    Physicists are past putting nails in the coffin of faster-than-light neutrinos; now they're planting the sod atop the idea's grave. As announced last week, all four of the particle detectors at Italy's Gran Sasso National Laboratory—as well as another team at Fermi National Accelerator Laboratory in Batavia, Illinois—have independently determined that neutrinos do not travel faster than light after all.

    Venus Silhouetted by the Sun

    CREDIT: NAOJ/JAXA

    The start of Venus's 5 to 6 June transit in front of the sun is captured here by Japan's HINODE spacecraft. The image shows the “arc of Venus,” the bright halo around the planet formed by sunlight refracted by the planet's atmosphere. Similar arcs around exoplanets transiting in front of their own, distant suns might also hold clues to those far-off planets' atmospheric compositions (Science, 11 May, p. 660).

    “We're also going to learn a lot about our telescopes,” says solar physicist Dean Pesnell, of NASA's Solar Dynamics Observatory in Greenbelt, Maryland. “[The transit] allows us to understand properties of telescopes that cause rings and ghost images, and can improve images of the sun based on that knowledge.” And the transit was a great outreach opportunity, adds Pesnell, who helped host a public viewing of the event in Fairbanks, Alaska. “It was really exciting to watch the kids see something happen that they will probably never see again.” The next transit will occur in 2117.

    … And in the Center Ring: Animal Acrobats

    CREDIT: JEAN-MICHEL MONGEAU, ARDIAN JUSUFI AND PAULINE JENNINGS, COURTESY OF POLYPEDAL LAB UC BERKELEY

    If you've ever seen a cockroach or a gecko disappear before your eyes, science now knows where they go. High-speed video of American cockroaches (Periplaneta americana) and flat-tailed house geckos (Hemidactylus platyurus) running up a cardboard ramp reveals that both creatures barely slow as they approach the edge.

    But instead of launching into space like miniature ski-jumpers, they anchor their hind limbs and swing down, perching on the underside of the ledge. It's the first time scientists have observed this behavior, says biomechanist Robert Full of the University of California, Berkeley. Cockroaches use claws on their rear legs like grappling hooks, while geckos use claws and sticky hairs on their back feet.

    One of Full's graduate students filmed flat-tailed house geckos in a Singapore forest performing the same maneuvers on ferns. Both species experience 3 to 4 g during these acrobatics, the researchers report online 6 June in PLoS ONE, similar to forces humans experience at the bottom of a bungee jump. They speculate that the 120-millisecond maneuver allows cockroaches and geckos to escape predators—such as a squealing human armed with a newspaper.

    By the Numbers

    20% — Percentage by which the Nobel Foundation will cut each Nobel Prize's cash award in 2012.

    635,000 — Number of martian craters at least 1 kilometer wide, according to a Journal of Geophysical Research-Planets study.

    ScienceLIVE

    Join us on Thursday, 21 June, at 3 p.m. EDT for a live chat on the science of organ transplants. http://scim.ag/science-live

  3. Newsmakers

    Paleoanthropologist Phillip Tobias Dies

    The legendary grand old man of South African paleoanthropology, Phillip Tobias, died on 7 June in Johannesburg, South Africa, at age 86. Tobias spent most of his career as head of the anatomy department at the University of the Witwatersrand, Johannesburg, where he succeeded another one of the field's legends, Raymond Dart, discoverer of the first known australopithecine (Science, 28 October 2005, p. 608).

    Tobias

    CREDIT: RAASGAT/WIKIPEDIA

    Tobias is probably best known as the last surviving member of the three-man team that also included famed fossil hunter Louis Leakey, which reported the discovery of Homo habilis in 1964. Tobias was also noted for his outspoken opposition to the racist system of apartheid.

    More recently, Tobias was enjoying the discovery of South Africa's latest contribution to paleoanthropology, a new species called Australopithecus sediba. “We were all thrilled by the discovery,” Tobias told Science in an interview in his Johannesburg office last year. “We paleoanthropologists are young at heart, and never cease to have a sense of wonderment and excitement.”

    Forestry Center Gets New Head

    Forestry and food security expert Peter Holmgren will be the next director general of the Center for International Forestry Research (CIFOR) in Bogor, Indonesia. A Swedish national, Holmgren has been at the United Nations' Food and Agriculture Organization (FAO) in Rome since 1998, where he has held a variety of positions related to forestry, climate change, and agricultural productivity. He is currently coordinating FAO's preparations for the United Nations Conference on Sustainable Development, Rio+20, being held in Rio de Janeiro, Brazil, starting 20 June.

    Holmgren

    CREDIT: GIULIO NAPOLITANO

    When he officially takes up his new position in September, Holmgren will succeed Frances Seymour, who has led CIFOR for 6 years. CIFOR is one of 15 members of the Consortium of International Agricultural Research Centers, which is working to reduce poverty and hunger and improve human health and nutrition through agricultural research. Holmgren says he wants to broaden the involvement of researchers and stakeholders to help promote evidence-based forestry policies and practices. “We need to bridge gaps between research and policy,” he says.

  4. Global Health

    How Do You Count the Dead?

    1. Gretchen Vogel

    Scientists agree they need better estimates for the death toll from the world's major killers. But they fiercely disagree on how to go about it.

    Not a statistic.

    An 8-month-old girl is buried in the Democratic Republic of the Congo. Most deaths in the world aren't officially recorded.

    CREDIT: © MARCUS BLEASDALE/VII/VII/CORBIS

    One of the best ways to help the living, says Prabhat Jha, is to count the dead. Understanding how many people die of which causes is invaluable for designing effective public health programs, says Jha, a global health expert at the University of Toronto in Canada. That's why he started an ambitious research project in India called the Million Death Study, which aims to record the causes of death for 1 million Indians between 1998 and 2014.

    But counting the dead can be extremely difficult. The problem is that most of the world's deaths occur in places with few or no hospitals or doctors to record deaths and their causes. Last month, for example, an international research group published the latest statistics on global child mortality in The Lancet. They estimated that 7.6 million children under age 5 died in 2010, well over half from infectious diseases. But fewer than 3% of those deaths were medically certified—assigned a cause by a health worker and recorded in an official database. For the other 97%, the scientists are forced to make sophisticated guesses.

    In doing so, they extrapolate from a patchwork of survey data, incomplete records, and research studies. Various groups use different statistical methods, however, sometimes resulting in very different numbers that are hotly debated. One study published in The Lancet in February, for example, found that 1.24 million people died from malaria in 2010; that's more than twice the estimate from the World Health Organization (WHO). Reactions from some in the malaria community were swift and harsh. “In terms of credibility I think public health science has been done a disservice by this paper,” says Robert Snow, a veteran malaria epidemiologist at the University of Oxford in the United Kingdom and the Kenya Medical Research Institute in Nairobi.

    The paper was only a preview of a much larger project counting deaths and disease prevalence by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, Seattle. The Global Burden of Disease, Injuries, and Risk Factors 2010 (GBD 2010) study is the most massive study of deaths and disease ever undertaken. It involves more than 1000 researchers and aims to assemble the cause of 1 billion deaths worldwide going back to 1980. It will be published in a series of papers later this year and is likely to trigger new debates.

    Some say that's necessary and healthy. “It's always worth looking at different approaches,” says Ties Boerma, director of measurement and health information systems at WHO. “We're all trying to make the best of incomplete and inaccurate data.” Others worry that the sharply diverging estimates and the bickering will erode policymakers' trust in science. “Can you imagine if I'm a minister of health in a country and am faced with new numbers every 2 years?” asks Zulfiqar Bhutta, an expert on maternal and child health at Aga Kahn University in Karachi, Pakistan. “At some stage we've got to stop confusing people.”

    Patchy data

    In the case of IHME's malaria study, the large gap between its estimate and WHO's was mainly due to one category: deaths of youth and adults in Africa. WHO estimated that in 2010, malaria killed 55,000 Africans over the age of 5; the IHME team concluded that the number was 435,000. Snow says that although WHO's numbers are too low, IHME's estimates, especially for adult deaths in Africa, are far too high. He notes that in several countries that keep very good records for malaria, such as Swaziland and Djibouti, IHME's formulas count more deaths than documented malaria cases, a sign that they're fundamentally off.

    The number of adult deaths surprised the IHME team as well, says epidemiologist and health economist Stephen Lim, the study's lead author. “There's lots of uncertainty,” he concedes. “The data are patchy, particularly in the hardest-hit areas.” However, after reexamining their data, the researchers remain convinced that their conclusions are on target. “Reasonable scientists will differ on a given point based on the evidence they have,” says epidemiologist and global health expert Alan Lopez of the University of Queensland in Brisbane, Australia, another co-author. “We do not know who's right. We are simply following our evidence.”

    There is more at stake than academic reputations. Global health estimates help determine where billions of dollars in health funding goes. Campaigners use them to justify public health spending on certain causes, such as measles immunization campaigns or AIDS prevention. The numbers also help to measure whether a campaign has made any difference, and they are one of the ways policymakers determine whether they are spending their money wisely.

    DIFFERENT STUDIES, VERY DIFFERENT NUMBERS SOURCE CREDITS (LEFT TO RIGHT): IHME AND WHO WORLD MALARIA REPORT 2011; CENTER FOR GLOBAL HEALTH RESEARCH, UNIVERSITY OF TORONTO; SWAROOP ET AL., BULL WORLD HEALTH ORGAN.; CHIPPAUX, BULL WORLD HEALTH ORGAN.; GUIDELINES FOR THE CLINICAL MANAGEMENT OF SNAKE BITES IN THE SOUTH-EAST ASIA REGION: WHO REG OFFICE FOR S.E. ASIA.; KASTURIRATNE ET AL., PLOS MED.; MOHAPATRA ET AL., PLOS NEGL. TROP. DIS.

    To understand how death-count studies can reach strikingly different results, consider one example. Suppose you're trying to find out how many people were sickened and killed by, say, pneumonia in Tanzania. The government's records of births and deaths are incomplete; only 17% of Tanzanian births are registered with officials, Boerma says. Hospitals have records, but they're not always accurate and up to date. Most important, most pneumonia patients never come to the hospital. They die at home without seeing a doctor who can make a diagnosis.

    So health metrics experts gather the best data they can, first from government and hospital records, and then from surveys, clinical studies, or any other possible source. Birth history surveys, for example, ask women not only how many children they have but also how many times they have given birth, which helps identify children who were born and died without ever being noted in official records. In a technique called verbal autopsy, trained field workers ask relatives of a deceased person a standard series of questions and record a short narrative of events leading up to the death. Physicians—or sometimes computer programs—evaluate the information and assign a likely cause of death.

    Researchers feed all the numbers into computer models that use sophisticated statistical techniques to fill in the gaps. Data on related circumstances such as rainfall, availability of clean water and health care, vaccine coverage, and mosquito densities—as well as data from nearby or comparable regions—all help the programs to churn out their estimates. The algorithms can fill in gaps in time as well as space. Data collected 5 years ago in one country can be combined with recent numbers from comparable sites to calculate current estimates.

    Crunching the numbers

    For their malaria estimates, Lim and his group generated thousands of models, which gave slightly different weights to various data sets. They then probed the models' accuracy by removing a subset of the data and testing each model's ability to predict the missing numbers. They used the same method to test socalled ensemble models, which combine individual models in different ways.

    IHME's mathematical prowess is undisputed. “Their work has transformed the way we think about the metrics of disease,” Snow says. Their approach “can be quite helpful: Gather all the data you can and see what they say,” adds Ramanan Laxminarayan, director of the Center for Disease Dynamics, Economics & Policy in New Delhi and Washington, D.C. But powerful computers can't make up for data that are simply too sparse, Laxminarayan says. The result “has to fit with some sort of on-the-ground validation.” For example, those who dispute IHME's malaria findings note that in the hardest-hit regions of Africa, most adults develop partial immunity to malaria, so a new infection is rarely deadly. If IHME's numbers are right, they would throw doubt on decades of malaria immunology and epidemiology, Snow says.

    The controversy stems primarily from IHME's choice of data sets. The team made a systematic effort to find as many verbal autopsy studies as possible, turning up thousands of studies. They then used computer programs to adjust for misclassified or unclear causes of death. But many researchers question whether verbal autopsies are a reliable way to measure malaria deaths, especially in adults.

    Even when a patient is alive, lab tests are often the only way to tell whether a sudden fever is caused by malaria, dengue, meningitis, or Japanese encephalitis. Some scientists contend that an accurate diagnosis based on a family's description of symptoms weeks or months after a death is impossible. “The tool is blunt,” Snow says. For determining whether an adult fever death was due to malaria, “it is probably as good as flipping a coin.”

    Jha counters that even if diagnosing an individual fever death as malaria is unreliable, researchers can check the population-level results by looking at the proportion of fever deaths that were caused by various diseases, taking into account other factors such as parasite prevalence or viral transmission patterns. Lim's IHME colleagues have conducted several studies to find out how accurate verbal autopsies are. In those analyses, Lim says, verbal autopsy actually seems to underestimate malaria deaths.

    WHO, in contrast, uses verbal autopsy data primarily for malaria deaths in children younger than 5 and in areas of low malaria transmission. (Most researchers agree that among common childhood diseases, malaria is distinct enough that verbal autopsy data are reliable.) WHO's main source of data are national registration and hospital records, which most experts say vastly undercount malaria deaths. For adult deaths in regions with heavy malaria burdens, WHO estimates the number of people living in areas with high, low, or no risk of malaria and uses mathematical models to extrapolate death rates based on the childhood numbers.

    Filling the gaps.

    A field worker in Bangladesh trained to conduct verbal autopsies asks a relative of a deceased person about the circumstances that led to the death.

    CREDIT: INSTITUTE FOR HEALTH METRICS AND EVALUATION

    Epidemiological terrorism

    WHO's methods receive plenty of criticism as well, and IHME's malaria numbers are not the first to diverge from WHO's estimates. Jha's Million Death Study, carried out with Indian colleagues, has also come up with significantly higher death totals, especially among adults. The researchers are monitoring 14 million people in 2.4 million Indian households that constitute a statistically representative sample of the population. Surveyors visit regularly to record births and deaths; if they hear of a recent death, a second field worker conducts a verbal autopsy. Two independent physicians evaluate the information and assign a cause of death. If they disagree, a third physician decides.

    Local support for the project “was phenomenal,” Jha says. “We throw these mortality numbers around. But for the families, [each death] is a tragedy”—and in many cases, the survey is the first time someone with authority is paying attention. “These invisible deaths become visible.”

    Jha likes to refer to his work as “epidemiological terrorism,” because it tends to explode public health experts' assumptions. For malaria, the team put India's annual death toll at 200,000 in a 2010 publication—more than 13 times WHO's estimate—with most deaths occurring among people aged 15 and older. Those numbers were controversial, but many experts said they could be plausible; malaria rates are lower in India than in sub-Saharan Africa, so adults have less natural immunity and are at greater risk of dying.

    Disputes about numbers aside, the study is revealing important patterns that can help policymakers, Jha says. In April 2011, the group reported that an estimated 50,000 people per year in India are dying of snakebites. (Other estimates had suggested it was 50,000 worldwide.) The country's snakebite deaths were concentrated in certain areas, the study found—an estimated 8700 occurred in the state of Uttar Pradesh alone. That suggests directing antivenom supplies to high-risk areas could save lives.

    The study has also found dramatic regional differences in death rates from cervical cancer, the leading cause of cancer deaths among Indian women. Rates in Muslim-majority areas are significantly lower than in Hindu-majority regions, perhaps because male circumcision reduces the risk of sexual transmission of the human papillomavirus (HPV), which causes cervical cancer. It also suggests, Jha says, that focusing HPV vaccination campaigns in high-prevalence regions might have the most effect. “None of these questions were hypothesized when we started the Million Death Study,” he says.

    More feuds expected

    The global health community is bracing for more explosions when the GBD 2010 results are published later this year. IHME plans to release complete and comparable estimates for the global death and disability caused by more than 200 conditions in 1990, 2005, and 2010. Observers from many fields “will see patterns and results that are surprising,” Lopez promises. New feuds are sure to result.

    Everyone agrees that the way to resolve those fights is to collect more complete information on the ground. “There is much more expenditure on places like IHME that are taking the data and churning them through black box models” than on strengthening reporting systems, Laxminarayan says.

    But so far, several attempts to improve the developing world's health record-keeping have come up short. In 2005, the Bill and Melinda Gates Foundation and WHO established the Health Metrics Network (HMN) to strengthen national health information systems. That's the right goal, says Kenneth Hill, a demographer at Harvard School of Public Health in Boston; improving civil registration systems is “where the world needs to go.” It's not there yet, however. “It's safe to say HMN has been a complete failure,” Hill says. “We really don't know how to improve registration systems. There hasn't been enough systematic research.”

    In countries without strong central registration systems, families and community officials have few incentives to register births or deaths, he says. “In most developing countries, bureaucracy is awful. Digging a hole is a hell of a lot simpler” than registering a loved one's death with local authorities.

    There are some positive signals, however. New technologies—cell phones and Internet access—are starting to have an impact, Snow says. “People are beginning to send real-time information to health authorities,” he says, and the supply of commodities to manage malaria, such as drugs and diagnostic tests, are now tied to providing reliable stock and disease information.

    Such information could help researchers come closer to a set of numbers they all can agree on. In the meantime, Jha hopes policymakers will see good news in a few things all studies agree on: for instance, that malaria deaths, especially among children, have fallen thanks to control programs. Similar success is possible if authorities take adult malaria seriously, as well, he says: “That message was a bit lost in the shouting about the numbers.”

  5. Profile: Rick Shine

    The Reluctant Toad Killer

    1. Sarah Zielinski*

    Australia's cane toad problem has distracted Rick Shine from the animals he truly loves, but the biologist may have an effective way to slow their invasion.

    Toad stopper.

    Shine is on friendly terms with this cane toad, but he wants to protect Australia from its relatives.

    CREDIT: TERRI SHINE

    While growing up in Brisbane in the 1950s, Rick Shine chased big bluetongue lizards in the neighbors' yards. By high school in Canberra, he was bringing home deadly brown snakes. “I can only wonder at my parents' forbearance,” he says.

    When Shine began college at Australian National University, he didn't yet know what he wanted to do in life, but then zoologist Richard Barwick showed him an appealing future. “Dick was the first professional reptile biologist that I ever met,” Shine says. “The light went on quite brightly when I recognized that there was such a thing as a career studying reptiles.”

    Shine, also smitten with the ideas of Darwin and the other giants of evolution, decided to pursue research and was soon applying evolutionary theory to the reptiles and amphibians that had fascinated him from a young age. In the 1980s, by then on the faculty at the University of Sydney, Shine set up a research station at Fogg Dam near the aptly named Australian town of Darwin, where he could study the ecology of the local pythons year after year.

    And then, in 2004, the cane toads came to Fogg Dam.

    Cane toads (Bufo marinus) have spread west from the Queensland coast since 1935, when Australian sugar growers, desperate to control beetles that were eating their crops, released several thousand young toads into their fields. The toads, native to Central and South America, had reportedly eaten enough similar beetles in Hawaii to improve sugar yields there, and they were considered less destructive than chemical pesticides. But Australia, with no native toads and plenty of suitable habitat, proved to be cane toad heaven. That soon created a new problem: The foreign amphibians produce a toxin that is deadly to many of the native predators that gobble them up. As the toads spread, a wave of death struck snakes, freshwater crocodiles, and other Australian animals. Today, cane toads are one of the continent's worst invasive species and number in the hundreds of millions.

    Finding himself on the leading edge of the invasion, Shine knew the toads would likely eradicate many of the animals he had studied for decades, so he reluctantly turned his attention to the unwelcome guest. “It was an extraordinary opportunity for a scientist,” he says, but it was also “so very bittersweet. … I thought we'd find out a lot about toads and do some great science, but we'd have very little actual management impact.”

    Less than a decade later, Shine's research has paid off, with dozens of findings covering basic toad biology and how the toads interact with Australia's native fauna, and even the discovery of a potentially new mechanism of evolution. Shine “is carrying on first-class 19th century natural history using 21st century techniques,” says John Endler, a veteran evolutionary biologist at Deakin University in Victoria, Australia.

    But the 62-year-old herpetologist's biggest breakthrough may be a recently devised strategy to turn the toad's own toxins against the invader. Shine has explored other ways to stop the animal's spread, but this time he believes he has struck gold. “I think that this will be the centerpiece of future efforts to control invasive cane toads,” he predicts.

    Team Bufo

    Walk into Shine's Sydney lab and you'll see a place full of the critters he would have loved to collect as a kid—snakes, frogs, lizards, a chameleon, and, of course, a couple of cane toads, including one named Gwendolyn. Shine spends less time in the lab and the field than he once did—“I probably just get in the way,” he says—but he has successfully resisted calls to pull him into university administration. Still, now that he is at the forefront of Australia's cane toad problem, Shine frequently finds himself in front of television cameras and community groups. He also spends a lot more time writing about cane toads for journals and magazines these days. “I enjoy the process of writing,” he says. “I suspect I would've been writing trashy crime novels if I hadn't been a professional scientist.”

    That love of writing certainly helped Shine produce the more than 750 papers he's authored in his career. Shine also modestly credits many of his published findings to the “sheer luck” of being in the right place at the right time, as well as having a small army of students and collaborators—he currently supervises about 20 scientists, including some postdocs and research assistants who have each stuck around for more than a decade.

    Shine chooses hard-working, motivated people and then guides them softly, says Ben Phillips, an evolutionary biologist at James Cook University in Townsville, Australia, and a former Shine student. Phillips describes his mentor as “quite unbosslike” and “very easygoing.” Shine is constantly listening to the people in his lab, Phillips says, and then “he puts a lot of effort into trying to improve what you're doing.”

    “Team Bufo,” as Shine's group is sometimes known, has garnered respect from the invasion biology community. “Shine's involvement in [cane toad research], with his laboratory and his linkages and his way of working, where he gets on with many people, has vastly improved our knowledge of the biology of the toad,” says veteran invasion biologist Tony Peacock, CEO of Australia's Cooperative Research Centres Association.

    Shine says he approaches topics with a willingness to be wrong. “I'm still appalled at my own inability to guess the right answer before we actually gather the data.”

    Take away the cane toad research, and Shine's resume is still full of first-class natural history discoveries. By studying the ecology and life histories of snakes in Australia and around the world, for example, he has provided fresh insight into the evolution of live birth (most reptiles lay eggs, but more than 2000 species give birth) and why male snakes are bigger than females in certain species, while the opposite is true in others (males tend to grow larger in species whose males have to fight other males during the mating season). Shine “really observes and thinks about what the animals are doing and … lets the hypothesis be generated by their natural world, which is the characteristic of a real scientist,” Endler says.

    In 2008, Shine and former student Daniel Warner, now at Iowa State University in Ames, finally provided experimental evidence for a 1970s-era theory for why some species have temperature-dependent sex determination. In certain reptiles—including all crocodilians, for example—nest temperature skews offspring gender ratio. Evolutionary biologists Eric Charnov and James Bull posited that there must be an evolutionary benefit for letting environmental conditions determine gender instead of genetics, but no one had been able to confirm that, in part because the phenomenon occurs in mostly long-lived animals.

    But Shine, who had been a postdoc in Charnov's lab, and Warner turned to the Jacky dragon, an Australian lizard with a life cycle of only a few years in which both sexes are born if nest temperatures are between 27°C and 30°C, but only females are born if it's colder or hotter. Hormonally manipulating the eggs in one experiment so that males were born outside the intermediate temperature range, the pair maintained those Jacky dragons in enclosures and showed that they didn't reproduce as well as typical males, an evolutionary disadvantage expected under the Charnov-Bull theory. “The sons that had been produced at the temperatures that normally produce sons were far more successful than sons that had been produced at any other temperature,” Shine says. “And the reverse went for the girls.”

    Snake study.

    Much of Shine's career has focused on Australia's native animals, such as pythons.

    CREDIT: PETER HARLOW

    Killer robot toads

    For almost a decade, cane toads have distracted Shine from the Jacky dragon, snakes, and other native animals he loves to study. Fifty years ago, no one would have thought that the cane toads would make it to his research station in Fogg Dam so quickly. The toads had initially traveled west steadily at about 10 kilometers per year. But then the amphibians at the front of the invasion began to change with every generation. The new offspring developed longer legs that enabled them to hop farther. And they didn't rest as much, hopping more frequently than previous generations of the toad, and thus moving longer distances on average. They also followed straighter paths and had greater endurance than the toads in the east—they could travel a kilometer or more each night. “You get these bizarre, robot cane toads that are designed to do nothing but hurtle as fast as possible, as straight as possible, across the landscape,” Shine says.

    The adaptations carried a price—about 10% of these toads now develop spinal arthritis—but the result was an invasion front that is now moving at a rate of 50 kilometers each year. “I've come to have a sneaking admiration for the toads,” Shine says. “They're an extraordinary invasion machine.”

    The longer Shine and his colleagues studied the toads, the more they became convinced that the amphibians' evolution was more complex than natural selection alone. They concluded there was another mechanism at work, one that Shine last year dubbed “spatial sorting” in an article in the Proceedings of the National Academy of Sciences. If you look at the population of cane toads spreading from east to west, toads at the front of the invasion in the west are the ones that have dispersed most quickly. When these toads on the leading edge breed, some of their offspring are naturally even faster dispersers, and they soon become the front of the invasion. When they breed and produce even faster offspring, the cycle continues, and the front moves more quickly every year. That's spatial sorting, “evolution through space, not time,” Shine says. In other words, it's survival of the fastest, not the fittest, when it comes to cane toads.

    Spatial sorting potentially has implications beyond invasion biology—species move all the time, driven by changes in climate or the opening of landscapes. And evidence of spatial sorting can be seen in other species; wood butterflies at the edge of their range expansion in England, for example, have stronger flight muscles.

    Not all evolutionary biologists are convinced that spatial sorting is a novel concept in their field; “I'd just call it gene flow,” says Mark McPeek of Dartmouth College. But some say it does appear to have been largely forgotten until Shine's work on cane toads. “Spatial sorting is a new component of evolution that people had ignored,” Endler contends. “It's a fundamental additional process of evolution.”

    Toxic backlash

    Understanding why cane toads have become such a problem is all well and good, but spatial sorting doesn't offer an obvious way to stop their spread across northern Australia. Farmers, volunteer groups, and government scientists have tried to get rid of the toads by manually removing eggs from ponds or physically killing adults, but both tactics have proved woefully inadequate. Attempts to identify or create a virus or other biocontrol agent that would wipe out the whole cane toad population have not borne fruit yet, either. Shine's group, for example, is still looking into using parasitic lungworms for cane toad control.

    Speedy toads.

    As cane toads have spread from Queensland, their invasion front has quickened (top) and local groups aiming to slow the toads (bottom) have had limited success.

    CREDITS (TOP TO BOTTOM): ADAPTED FROM URBAN ET AL., THE AMERICAN NATURALIST, MARCH 2008; KIM HAND

    Given the cane toad's toxic payload, Australians have long assumed that the amphibian's native predators were doomed, but it turns out that's not necessarily the case. The cane toad's toxins are “devastating for a small number of species,” Shine says, “and really no big deal for most of the others.”

    Raptors, for instance, have figured out how to avoid the majority of the toad's toxins by eating only their tongues. And Australia's native frogs have quickly learned that cane toads aren't tasty and now avoid them. Shine even taught young captive quolls, native catlike marsupials, that the toads taste bad by feeding them a nonlethal dead toad laced with a nausea-inducing chemical; when released into the wild, those quolls taught their offspring to avoid the amphibians.

    This may help native predators to survive, but it can't do too much to slow the toads. “If they can have 30,000 kids a year, then really, you're not going to have too much impact just removing the adults,” Shine notes. “It's more like dealing with an insect pest than it is like dealing with the average vertebrate.”

    That's why an unexpected discovery by Shine's team—that cane toads are sometimes cannibals, with tadpoles of the species consuming cane toad eggs—finally has Shine and others hopeful. What some might have dismissed as a quirk of nature, Shine has turned into a plan to get rid of the toads.

    It all started with the observation that native frog tadpoles would munch on cane toad eggs and soon die. When Shine, postdoc Michael Crossland, and their colleagues used those eggs as bait in traps, they found cane toad, not frog, tadpoles by the dozen. Unexpectedly, they found that the toad tadpoles were lured to the eggs by the same toxins the adult toads use to deter and poison predators. Crossland and Shine then used those attractants as bait in funnel traps in ponds and caught tens of thousands of toad tadpoles in just a few days, removing nearly all that were living in a pond, with very few native frog tadpoles, fish, or insects as by-catch.

    This “is a testament to the value of pure research,” Phillips says. Shine “discovered something that is a chink in the toad's armor and discovered that it can be exploited.”

    Crossland and Shine have tried the toad toxin-laden traps in a half-dozen ponds so far, including one in Sydney, at the edge of the cane toad's Australian range, and the traps have been a success each time. Shine's team presents the trap results this week in the Proceedings of the Royal Society B.

    Shine envisions a day when the community groups that currently carry out toad kills are instead enlisted to collect the animals, harvest their toxins, and build tadpole traps. It's still only a local solution, but it could prove invaluable in places such as nature reserves. The trap strategy “seems like it could be very promising at that level,” says ecologist David Skelly of Yale University.

    But, Skelly adds, “I'm not sure this is something that could knock the invasion wave back.” Others say that shouldn't be the key goal. “People always think in terms of ‘Wouldn't it be nice if we had some sort of biological control [for cane toads] and knock them all out,’” says invasion biologist Peacock. “Rick is working beyond that. … We should be concentrating on those areas and those ecosystems where the toads do the most damage,” such as where they interact with the northern quoll, the species most likely to be driven extinct by the toad invasion.

    Shine himself acknowledges that the toxin traps aren't the ultimate toad killers. “We won't have a magic bullet to get rid of cane toads from Australia,” he says, “but we now have an approach that can massively reduce their numbers.”

    That may disappoint some cane toad–busting groups, but it's a hallmark of Shine's “pragmatic” and “clear-eyed” approach to this research, according to Skelly. And even if Shine hasn't found the Holy Grail of cane toad control, he's certainly brought Australia hope. “We really have a much better idea of how one of the classic, textbook invasive species influences environments,” Skelly says, “because [Shine has] been willing … and been productive enough to tell the whole story about this species.”

    • * Sarah Zielinski is a freelance writer based in Washington, D.C.

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