News this Week

Science  22 Jul 2011:
Vol. 333, Issue 6041, pp. 390

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  1. Around the World

    1 - Botswana, Kenya, and Uganda
    In Major Advance, Anti-HIV Pills Protect Uninfected Heterosexuals
    2 - London
    House of Lords: Rethink the Nudge
    3 - Melbourne, Australia
    Vandals Attack Transgenic Wheat Test Plot
    4 - Paris
    E-mails Not So Green

    Botswana, Kenya, and Uganda

    In Major Advance, Anti-HIV Pills Protect Uninfected Heterosexuals

    Two studies in sub-Saharan Africa have shown for the first time that daily doses of anti-HIV pills taken by uninfected men and women can prevent heterosexual spread of the virus (see p. 393). An earlier trial proved that such pre-exposure prophylaxis (PrEP) could protect men who have sex with men, but the new results, simultaneously announced on 13 July, were widely hailed as a “breakthrough” in HIV prevention as heterosexual transmission accounts for most of the 34 million infections in the world.

    Partners PrEP Study site in Thika, Kenya


    The more compelling of the two studies, Partners PrEP, began in July 2008 with 4758 discordant couples in Kenya and Uganda that had only one HIV-infected partner. The University of Washington, Seattle–run trial recruited relatively healthy infected people not on treatment and gave the uninfected partner either a placebo or a pill that contained a licensed anti-HIV drug. The more powerful of two drugs tested, Truvada, reduced transmission by 73%. A second, smaller PrEP study of Truvada run in Botswana by the U.S. Centers for Disease Control and Prevention found a 63% reduction in heterosexuals who were not in a long-term relationship with an infected partner.


    House of Lords: Rethink the Nudge

    It's going to take more than a “nudge” for people to change bad habits. So says the United Kingdom's House of Lords Science and Technology Sub-Committee. A committee report issued 19 July on behavioral change policy found that “nudges”—attempts to change people's behavior by altering the environment or context of their decisions, such as placing candy bars near the register—are, by themselves, ineffective in changing behavior.

    The U.K. government is keen to address issues such as obesity and carbon emissions by finding nonregulatory ways, such as nudging, to change behavior. But the report finds that a mixture of interventions is required, including regulation and taxation. “The concern we raised … is that government and policymakers were in danger of ignoring some of the very potent means or levers for changing behavior if they focused only on nudging,” says Theresa Marteau, director of the Behavior and Health Research Unit at the University of Cambridge Institute of Public Health in the United Kingdom.

    Melbourne, Australia

    Vandals Attack Transgenic Wheat Test Plot

    Just after midnight on 14 July, three activists wielding motorized grass trimmers broke into an agricultural test plot operated by CSIRO, Australia's preeminent research organization. They damaged hundreds of genetically modified (GM) wheat plants.

    Greenpeace claimed responsibility. In a news release, the organization states that the vandalism “follows the revelation” that CSIRO “is conducting the world's first human feeding trials of GM wheat, without adequate safety testing.”

    A Greenpeace activist destroys GM wheat.


    The vandalism caught CSIRO off-guard. “This may have cost us a year of research and several hundred thousand dollars,” says CSIRO Plant Industry Chief Jeremy Burdon. The activists damaged GM wheat plants that CSIRO has been developing over the past 13 years with the Australian Grains Research and Development Corp. and the French company Limagrain. One variety boosts yields; another more efficiently metabolizes nitrogen; a third triples levels of amylose, a starch that doesn't spike blood sugar levels.

    Two years ago, the Office of the Gene Technology Regulator granted CSIRO permission to test the high amylose wheat in a short-term trial in a small number of volunteers. An ethics committee approved the trial in 2010. If the experiment goes ahead, it would indeed be the world's first human trial of GM wheat, says Bruce Lee, director of CSIRO Food Futures Flagship.


    E-mails Not So Green

    Switching communication from paper to electronics may not help the planet as much as has been claimed.

    A report by the consultants BIO Intelligence Service (BIOIS) for the French government's Environment and Energy Management Agency (Ademe) reckons that if every staff member in a company with 100 employees sent 10% less e-mails for a year, they would save CO2 emissions equivalent to one round-trip flight between Paris and New York.

    Although not the first to show that information and communication technology (ICT) pollutes the planet, the BIOIS report offers surprising tips for reducing the impact. For example, if a four-page document takes more than 15 minutes to read, it is better to print it out in black and white on both sides of the paper.

    Other advice is to limit the number of recipients for each e-mail, to clean out the e-mail inbox regularly, and to enter the URL address directly rather than use a search engine.

    BIOIS built on its report for the European Commission in 2008, which predicted that ICT could double its share of Europe's greenhouse gas emissions from 2% in 2005 to 4% in 2020. The number of e-mails sent each day worldwide is expected to about double from 247 billion in 2009 to 507 billion in 2013.

  2. Newsmakers

    Three Q's

    On 1 July, an ExxonMobil oil pipeline under the Yellowstone River in Montana burst, spilling oil into the river and onto its banks. Montana Governor Brian Schweitzer, a soil scientist, has criticized how ExxonMobil and the Environmental Protection Agency (EPA) responded to the disaster.



    Q:What made this spill particularly bad?

    If we take [ExxonMobil's reported 40,000 gallons] at face value, it's not that much [oil]. The problem is that the river was flooding at the time and a higher percentage of the oil went over the banks relative to what was in the river because it floats on the top.

    Q:As a soil scientist yourself, what are you concerned about?

    Our concern is what that is doing to microbial activity, to insect hatch, and how that would relate to amphibians and reptiles. These lowland wetland areas, that's the health and wealth, biologically, of a river.

    Q:You're crowdsourcing soil sampling to the people of Montana. Why?

    I was a little frustrated that 2 weeks after the spill, EPA hadn't drawn a single soil sample. We said to landowners, “Perhaps you should draw some samples yourself.” Private landowners have been bringing us samples. … We'll run those tests, sampling the depth that soil has been penetrated, the components left in the oil [after] some evaporates and some microbial activity breaks it down.

    Eqypt's Antiquities Boss Is Sacked

    After nearly a decade as chief of Egypt's antiquities, Zahi Hawass is out of a job.

    The 64-year-old archaeologist was fired 17 July by Prime Minister Essam Sharaf as part of a wider shakeup of his cabinet. Protestors at Cairo's Tahrir Square had been calling for his ouster as minister of antiquities for months. “All the devils united against me,” Hawass told ScienceInsider.



    The country's most prominent figure in archaeology, Hawass was instrumental in sending large blockbuster exhibits abroad, creating new museums, and pressuring foreign excavators to publish their finds more quickly. But he was also criticized for his portrayal on American television of archaeology as treasure hunting, excoriated for his dictatorial management style, and accused of shoddy research.

    Egyptian critics say they are delighted by the departure of Hawass. “Finally, we got rid of him,” says Amany Taha, a Cairo tour guide active in the protests.

    But some foreign archaeologists say they will be sorry to lose Hawass. “Now that he is gone, I beg you to remember all the good that Zahi did for Egypt and Egyptian antiquities in his term,” says W. Raymond Johnson, an archaeologist at the University of Chicago in Illinois who works at Luxor.

  3. Random Sample

    'Lost' Frog Found on Borneo


    A few sightings and a black-and-white illustration dating to the early 20th century—that was all scientists knew of the Bornean rainbow toad for 87 years. Then at the end of last year, researchers found three of the brightly colored amphibians high in trees along the rugged ridges that separate Malaysian and Indonesian Borneo. Also called the Sambas stream toad or Ansonia latidisca, the species is listed as endangered on the International Union for Conservation of Nature Red List of Threatened Species, and it may warrant protection under local conservation laws. The area in which the individuals were found is not currently protected. The discovery was announced by Conservation International, which had included the toad on its list of the world's top 10 most wanted lost frogs.

    Antarctica and Electronica: Launching The Book of Ice


    Because who wants to sit through another panel discussion, welcome to the next generation of book launch parties:

    They're in an industrial art space in New York City. There's a D.J. (and he's also the author). Columbia University physicist Brian Greene, who wrote the book's preface, may make an appearance. More than 100 local scientists and artists drink, gab, and carefully avoid a 2-meter-tall sculpture of a human ear.

    Paul D. Miller, aka “DJ Spooky, That Subliminal Kid,” launched The Book of Ice at the Eyebeam Art + Technology Center in New York on 13 July. Like the book itself, the evening combined music, graphic design, brief tutorials on climate science, and soupçons of environmental advocacy. Live strings and electronic beats were sandwiched between short-but-stirring talks by Edward Morris of the Green Patriot Project, Bill McKibben of (who skyped in from Europe for the occasion), Anna Lappé of the Small Planet Institute, and Miller, whose charm saved the evening from what could have been a dangerously self-congratulatory mix of activism and hipsterism.

    Even the U.S. Environmental Protection Agency showed up: Phillip Ritz of the EPA's Region 2 was there. Ritz says he e-mailed Miller the next day to ask whether the author/D.J. would give a talk at EPA's New York offices about the artistic expression of climate change. “These parties are fun,” Ritz says—but, he adds, they also present unusual networking potential. “Professionals from music, publishing, policy, science, and engineering—we don't normally run into each other.”

    By the Numbers

    1 — Number of circuits Neptune has completed around the sun since its discovery 165 years ago. NASA is marking the occasion with anniversary pictures from Hubble.

    45% — Percentage of gene expression studies that submit data to public databases, according to a PLoS ONE study that examined 11,603 studies from 2000 through 2009. Data on cancer and human subjects was shared least often.

  4. Behavioral Ecology

    Why Do Parrots Talk? Venezuelan Site Offers Clues

    1. Virginia Morell

    The world's longest-running study of wild parrots shifts focus to a new question: What do parrots say to each other in the wild?

    Family ties.

    Wild parrotlet chicks and mother cozy up in an artificial nesting box.


    HATO MASAGUARAL, CALABOZO, VENEZUELA—Back in July 1985, while studying raptors on this working cattle ranch, Steve Beissinger noticed a pair of green-rumped parrotlets nesting in a hollowed-out fence post. “Parrots usually nest high in the treetops, which makes them extremely difficult to study, but these were nesting just a few feet off the ground,” recalls Beissinger, an ecologist at the University of California, Berkeley. “I immediately wondered, ‘Would they nest in artificial boxes?’”

    Two years later, after experimenting with designs, Beissinger constructed a faux box from a 1-meter-long piece of PVC pipe lined with wire mesh and removable lids on top and bottom. He filled the bottom of the tube with wood shavings, hung the contraption from a post at the ranch, and waited. About a month later, a pair of the parakeet-sized birds known scientifically as Forpus passerinus took up residence. The next year, Beissinger added 40 more PVC boxes, and many were soon occupied.

    Today, the ranch's fence lines look like a parrotlet condo development. Pairs are busy nesting, with females sequestered inside the boxes with eggs and chicks. They emerge when their mates return from foraging with crops full of seeds to share with the family, while all parties exchange short peeping calls. Meanwhile, fledglings congregate in loud, raucous groups in the nearby mango trees, also calling for their next meals.

    Although Beissinger didn't realize it in 1987, he had launched the world's longest-running study of wild parrots, a project that is entering its 24th year—making it the parrot equivalent of Jane Goodall's long-term study of chimpanzees in Tanzania and Cynthia Moss's elephant project in Kenya. And just as those studies tracking individual animals changed our understanding of chimpanzees and elephants, this one is opening new windows into the minds and behaviors of parrots.

    The ranch site “is a phenomenal system,” says Noel Snyder, a retired ornithologist with the U.S. Fish and Wildlife Service in Portal, Arizona, and it has yielded “a gold mine of data” because the birds “can be observed throughout their lives and manipulated experimentally.”

    Thanks to Beissinger's nesting boxes, which now number 106, researchers have discovered details of the parrotlets' ecology and life histories, and the project has now entered a new phase focusing on their communicative skills. Last week, researchers led by graduate student and ornithologist Karl Berg of Cornell University reported that the contact calls of wild parrotlet nestlings—vocalizations that function much like a name—are not genetically programmed. Instead, they learn these calls from their parents, almost like human children learning their names, Berg and colleagues reported in a paper in the Proceedings of the Royal Society B.

    Berg's is the first study to provide experimental evidence for learned vocalizations in wild parrots. Because both male and female parrots learn new calls throughout life (in contrast to most songbirds, in which only young males learn), Berg and others say that parrots may be the best animal model yet for investigating how humans acquire speech.

    Finding out what parrots are saying to each other in the wild, and why, requires long-term data and a deep understanding of parrotlet ecology—which is what the ranch site provides, Berg says. “You can't just walk into the forest and start swapping eggs between nests” to find out if calls are innate or learned, he says. “You have to know the parents' pedigrees.” Adds Berg's thesis adviser, Jack Bradbury, a behavioral ecologist and professor emeritus at Cornell, “There is nothing like [the ranch site] for parrots anywhere else on the planet.”

    Talking back

    Since the days of Aristotle, people have known that parrots are smart, with sharp memories and an uncanny ability to mimic human words and speech. Like humans, parrots are a social species that has evolved rapid-fire vocalizations to communicate with their conspecifics. In captivity, parrots do not simply react when humans speak to them (something dogs, cats, chimpanzees and other animals do as well); they also articulate responses, almost as if talking back. Sometimes, as Alex, the famous African Gray parrot who was studied for 30 years, demonstrated, captive parrots will even use words in the correct context (Science, 11 February 2000, p. 980).

    Did Alex really “talk”? Despite his impressive accomplishments, researchers continue to debate the meaning behind his words. Many say that a true understanding of parrots' communicative talents also requires understanding what purpose those abilities serve in the wild and why they evolved in the first place. Why would a bird spend so much time, energy, and brainpower on vocalization, wonders Timothy Wright, a behavioral ecologist at New Mexico State University in Las Cruces, who discovered dialects in the calls of yellow-naped Amazon parrots. “What is the advantage to the individual of learning all these vocalizations?”

    Bradbury agrees that captive parrots are “great mimics and clever. But the question was always, ‘Why?’ What are they doing in the wild” that would necessitate these behaviors? He has proposed that parrots, which live in dynamic flocks, may be using their vocal mimicry to help negotiate flock separations and mergers. For instance, orange-fronted conures exchange contact calls in late afternoon when recruiting others to their sleeping roosts.

    Answering such questions with wild parrots isn't easy. The logistics are “formidable,” Snyder says. Most parrot species are long-lived, nest high in the canopy, and travel long distances. They are difficult to outfit with radio transmitters—or even standard bird bands—because some species can tear these off with their powerful beaks. Even telling males apart from females is a chore for most species because the two often look identical.

    To have and to hold.

    Steve Beissinger and a colleague set up a mist net near a nesting box; when they catch parrotlets, they band and measure them (inset).


    Enter the ranch site, where Beissinger's original interest was in parrot ecology. “Parrots are one of the most threatened groups of birds in the world [one-third of New World species are at risk of extinction], because of poaching and habitat loss, and yet we know so little about them in the wild,” he says. “Here was a chance to find out something about what they do.”

    Over the years, Beissinger and his team have banded more than 8500 parrotlets, documented 3000 nesting attempts, and followed the fates of 16,000 eggs. The parrotlets are surprisingly tolerant of the scientists, who monitor the boxes daily, marking each egg with a coded number, and later handling the chicks, weighing and measuring them, and fixing aluminum and plastic colored bands on their tiny legs. Records are kept of every banded bird and its pedigree, so researchers know who is related to whom.

    In a string of papers published in journals such as Animal Behaviour, Auk, and Ecology Letters, Beissinger and his colleagues reported the parrotlets' complex social system, in which males outnumber females and strongly monogamous pairs will fight fiercely over highly prized nest boxes. (This may help explain why the tiny birds tolerate researchers' handling rather than give up those boxes.) A single bird can rarely defend a nest on its own, so if a parent dies or is poached, the entire family is often lost as other birds move in, kill the nestlings, and take over the box. That finding influenced the drafting of wild bird import regulations in the United States.

    Beissinger's research laid the groundwork for Berg's communication studies. “We worked out all the ecology, demography, the social systems, the hatching asynchrony,” which means that chicks in a nest can range in age from a few days to 2 weeks old, Beissinger says. “And because we knew all of that, Berg could start investigating the vocalizations,” which he began doing 5 years ago for his doctoral thesis.

    Home sweet home.

    A pair of wild parrotlets claims a nesting box.


    Into the wild

    In captivity, parrots imitate human voices and other sounds. But in the wild, as Bradbury and other researchers have shown, parrots imitate each other. They match calls as pairs and as groups and will even match vocal dialects.

    To begin to understand how parrotlets learn such vocalizations, Berg started with their contact calls, the fundamental parrot call. Even Berg admits that to human ears, it doesn't sound like much—just a series of simple peeps. Our ears aren't able to hear the variation and information in the calls because “they are just too fast,” Berg says. “The parents can make 20 contact calls in the time it takes you to sneeze.” When slowed down for our ears, a parrotlet's single peep sounds more like eh-ehhh-gehhhlll-grrr-whoeeeeee. (Listen to contact calls at normal speed, and slowed down, at “You can't make sense of their vocalizations just by listening. You can't imitate their calls like you can whistle a songbird's tune,” Berg says. “The only way we can study them is by converting their calls to spectrograms, then running these through computer programs” that search for subtle similarities and that Bradbury and colleague Kathryn Cortopassi spent years developing.

    “What is surprising is that we pulled this off in the wild.”



    Parrotlets, like other parrots, use contact calls in a variety of ways to communicate with other members of their flocks. For instance, when a male returns to his nesting box, he emits his peep. In response, his mate may make her call, or both their calls, as if saying, “I hear you, Joe. It's Betty here.” Berg suspects that other information is also being communicated. “There is a lot more in that call than ‘Hi, honey, I'm home,’” he says.

    He hasn't proved that yet, however. Indeed, pinning down the fundamental biology and cognition behind parrot calls has been difficult. Researchers hadn't even demonstrated that the calls are learned, rather than innate, although captive studies had suggested this. Bradbury, who studied orange-fronted conures, a larger parrot, in Costa Rica, suspected that the conures learned their “chee” contact call while still in their nests, “but it was just impossible to get a large enough sample size to show this,” he says. He was lucky if he had one nest a season to study.

    Berg, working at the ranch with 106 nesting boxes and 20 years of bird pedigrees, had the perfect setup to explore the question. He swapped complete clutches among nine nests so that chicks were raised by unrelated foster parents, who had different calls from those of the biological parents; he used eight other nests as controls. After the chicks hatched, Berg made weekly video and audio recordings inside the nests as well as outside during the parents' arrivals and departures.

    In the Cornell Lab of Ornithology, Berg compared spectrograms and statistically analyzed 5000 such calls. He found that the parents provided a basic call template, which each chick learned and slightly modified to make its own unique contact call. Nestlings in the same family acquired slightly similar calls no matter who their biological parents were, enabling family members to recognize each other after they left the nest. Like humans, parrotlets have extended parental care, with parents feeding fledglings for another 3 weeks. The young birds roost in large, communal groups with as many as 300 other recently fledged chicks—“which makes it just that much harder for the parents to find their own kids,” Berg says. “They'd never manage without the contact calls.”

    Others find the study convincing and want more. “Berg's study gets at the heart of why they are learning that initial contact call of the parents,” Wright says. “Through the parrotlets we have the opportunity to find out if this kind of learning extends into adulthood. It seems that it does, because the parrotlet pairs match their calls—but, again, why?”

    One obvious next question is whether parrotlet parents deliberately give chicks contact calls, as human parents give children their names. No other species has yet been shown to do this, but such a behavior would help the young birds establish identities in their highly social communities, Berg says.

    Others are intrigued by how young the birds are when they begin to learn the calls. “Berg's study shows that the parrotlets are capable of vocal learning at a very early stage,” notes Ofer Tchernichovski, a biopsychologist at Hunter College in New York City. “Is it similar to speech learning in human infants?”

    Berg points out that scientists still debate how and when language emerges in human infants (Science, 21 May 2010, p. 969). “Parrots could be the best animal model for investigating this question,” he says, noting that like human infants, parrots are born dumb and utterly helpless, and have extended dependent childhoods and relatively large brains. Also like humans, parrots hit a key developmental milestone when they begin to learn their “names.” “There's a moderate convergence between parrots and humans,” he says.

    “In some ways, our results are not surprising,” Berg says of his study. “But what is surprising is that we pulled this off in the wild.”

  5. Glaciology

    Antarctic Ice's Future Still Mired in Its Murky Past

    1. Richard A. Kerr

    As shrinking ice sheets raise sea level, estimates of how quickly the frozen continent is losing and gaining ice remain slippery.

    Glaciologists are worried, deeply worried. They clearly see that tongues of ice draining Greenland's glacial stores into the sea have lately sped up and the ice is melting faster than ever. The great island has clearly been losing ice faster than snow can replenish it, and the deficit is raising seas worldwide. In the south, the ice sheet of West Antarctica is in the same boat. Warming air and sea seem to be behind both net losses of ice. But what of the ice of East Antarctica, more than eight times the mass of either Greenland's or West Antarctica's?

    A new reanalysis by two NASA scientists of the three standard ice-monitoring techniques slashes the estimated loss from East Antarctica, challenging the large, headline-grabbing losses reported lately for the continent as a whole. Although not the final word, the new study shows that researchers still have a lot to learn about the vast East Antarctic Ice Sheet.

    High or low?

    Comprehensive estimates of ice sheet losses that raise sea level (red boxes, red line, and red spot) that include all three methods tend to be smaller than single-method estimates (turquoise, blue, and purple).


    Understanding the role of East Antarctica is one key to figuring out what the ice sheets, and thus sea level, will be doing by century's end. The new study “is a step in that direction,” says glaciologist Robert Bindschadler of NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland, who was not involved in the work. “It really is up to the community to sort out the various [ice-monitoring] techniques. This information is wanted by yesterday.”

    Glaciologists have not yet sorted out Antarctica's ice loss because “they're doing something very difficult,” glaciologist Richard Alley of Pennsylvania State University, University Park, says. By one means or another, they are trying to pin down a tiny change from year to year in the small difference between large amounts of frozen water: the amount of snow that falls on Antarctica and the amount of ice that flows into the sea. With the new study, scientists now disagree whether Antarctica is losing roughly 50 billion or 150 billion tons of ice each year. Meanwhile, something like 2400 billion tons of snow falls there each year.

    Gauging a change of a few percent in the flow of ice through the continent's glacial stores has proved a challenge for ice-monitoring techniques. In their paper published online on 13 May in Surveys in Geophysics, glaciologists H. Jay Zwally and Mario Giovinetto of GSFC assess the published results from all three of the standard methods and present their own “preferred estimate” for Antarctic ice mass change.

    Each of the three methods has its foibles. In the first, altimetry, researchers bounce laser or radar signals off the ice to measure its height and thus its volume. The method has been used to survey most of the continent, but converting changes in volume to changes in mass raises major uncertainties. The second technique, gravity, employs the two satellites of the Gravity Recovery and Climate Experiment flying over the ice in tight formation to measure mass directly. But that record goes back to only 2002, and data analysis is tricky. Finally, the input-minus-output method works by subtracting ice flow into the sea from total snowfall. Both numbers are huge, however, and the mass of snow falling on East Antarctica is especially hard to gauge.

    Zwally and Giovinetto reassessed published altimeter and gravity estimates. They also recalculated an earlier input-minus-output estimate published by radar scientist Eric Rignot of NASA's Jet Propulsion Laboratory in Pasadena, California, and his colleagues. The pair challenged some of Rignot's assumptions, including some underlying his estimate of ice loss along the 15% of the ice sheet's periphery where no one had made measurements. And whereas Rignot had estimated all East Antarctic snowfall from a weather model, Zwally and Giovinetto substituted field measurements for 6% of the area. Those changes reduced the loss estimated using input-minus-output by 90%.

    Finally, Zwally and Giovinetto made preferred estimates for all of Antarctica, taking into account the strengths and weaknesses of the three methods. The figures came in on the low side. Published estimates for the period 1992 to 2009 had ranged from a net gain of 50 billion tons per year to a loss of 250 billion tons per year. Their new preferred estimate for 1992 to 2005 spans a far narrower range, from a gain of 27 billion tons to a loss of just 40 billion tons per year. For 1992 to 2001, the researchers estimate a loss of only 31 billion tons per year. If they are right, an increase in East Antarctic snowfall—possibly brought on by global warming—may have been balancing much of the accelerated loss from West Antarctica.

    The new analysis is a “perfectly reasonable reinterpretation,” glaciologist Andrew Shepherd of the University of Leeds, U.K., says. “The paper's main contribution is a very convincing argument that one needs to account for uncertainties in a consistent way.” Not that this is the final word. “I wouldn't say this shows Eric is wrong,” Alley says, “nor that Jay is wrong.” In fact, Shepherd says, “we've always felt the number is somewhere in between” the extreme estimates.

    Getting more than a feeling for what Antarctic ice is doing to sea level will take more than one group's reassessment of the published literature, researchers agree. The Intergovernmental Panel on Climate Change (IPCC) is already working on an ice balance assessment for its report due in mid-September 2013, but researchers say more must be done to focus scientists' attention on the problem. “People's heads need to be knocked together,” Shepherd says. Bindschadler agrees. The European Space Agency and NASA have launched an effort to work through the uncertainties, but with IPCC looming, Bindschadler says, “time's running out.”

  6. 7th World Congress On Mummy Studies

    In the Hands of Mummy Experts, Ancient Faces Gain New Life

    1. Heather Pringle*

    At the meeting, researchers presented facial reconstructions of a British boy from the 18th century and a warrior from the Amazonian rainforest who died more than 80 years ago.

    When standing before the desiccated face of an ancient mummy, archaeologists and museum visitors alike often have the same question: What did this person look like in life? Experts in the art and science of facial reconstruction use a host of sophisticated techniques to find out, from stable isotope studies to hair analysis to computed tomography (CT) scans. At the meeting, researchers presented several outstanding examples, including a British boy from the 18th century and a warrior from the Amazonian rainforest who died more than 80 years ago.

    Monkey head or human?

    Researchers forensically reconstructed the face of a Shuar shrunken head.


    The warrior is from the Shuar tribe of Ecuador and Peru, who decapitated their enemies and then shrunk their heads, believing that this would imprison vengeful spirits. Researchers don't know when this tradition began, but some Shuar practiced it until the 1970s. Back in 1923, one such head or tsantsa made its way to a museum in Dundee, U.K.

    This tsantsa, with its snoutlike nose and protruding lips, looks more like a monkey than a human—and the Shuar were known to shrink monkey heads. Was the head even human? To find out, Tobias Houlton of the University of Dundee's Centre for Anatomy and Human Identification took up the challenge of forensically reconstructing its face, something never done before with a shrunken head.

    Houlton first analyzed cross sections of the hair microscopically and found that it met six key criteria for being human, such as even distribution of pigment granules through the cortex. The hair's color, straight shaft, and other traits suggested that it came from a Native American.

    Lost boy.

    Computed tomography helped recreate the face (left) of an 18th century boy whose body was used as an anatomical specimen.


    Next, Houlton did some experimental archaeology using a Shuar technique for head shrinking, documented by an anthropologist who interviewed Shuar elders in the 1990s. Houlton got a pig's head from a butcher, removed its skull and brain, and pinned the lips shut with small sticks. Then he shrank the soft tissue by boiling it in river water, putting hot stones in the neck cavity, and drying it in an oven. He took detailed before-and-after cranial measurements. Houlton found that skin attached to cartilaginous tissue, such as the lower nose, shrank less than other facial skin, forcing the nose into an upturned position. In addition, the Shuar often tugged at the lips to pull them out and mock the dead.

    The Shuar rarely shrank the heads of women, reserving this treatment almost exclusively for male warriors killed in battle, so Houlton assumed the tsantsa was of a male in his 20s.

    To reconstruct the face, Houlton created a computer template of a skull based on measurements of Peruvian skulls, the closest available data set geographically to the Shuar villages. Then he graphically created the soft tissue, modifying a 3D scan of the tsantsa to reverse the effects of shrinkage based on his pig experiment and of lip tugging. Finally, he used artistic license to add body ornamentation and skin color to match those of the Shuar.

    Although Houlton cautions that his work is science's best guess rather than certain knowledge, his image is a credible view of a long-lost warrior, other researchers say. The project itself is “a tour de force, from the background literature search to the sophisticated computer work,” concludes anthropologist Alana Cordy-Collins of the University of San Diego in California.

    A mysterious body donation sparked another striking reconstruction. In the late 2000s, the University of Dundee received the partially preserved body of a child once used as an anatomical specimen. No one knew when the child had died or where the body came from originally. Caroline Wilkinson, an artist and craniofacial identification expert at the university, set out to recreate the child's face with a team of experts. Forensic anthropologist Susan Black, also of Dundee, examined CT scans of the body, whose skull was partially removed and whose chest was opened for teaching purposes. She found it was that of an 8-year-old boy. Stable isotope analysis of a bone sample by University of Dundee chemist Wolfram Meier-Augenstein revealed that the child had dined frequently on animal protein, suggesting he had been rich or middle class.

    Inspecting the body, team members noticed that someone had poured a red resin that smelled like beeswax on and inside the main arteries and veins so that these would be more visible to students. By the 18th century, British anatomists were using their own recipes for such resins—and many of these formulas are preserved in a Glasgow museum. “We took a sample of the resin and compared it to the different recipes,” Wilkinson said. It closely matched one made with beeswax, vermilion, and other ingredients used by Scottish surgeon John Hunter of St. George's Hospital in London, who died in 1793. “It was a very close match, so it was likely either Hunter or one of his students who produced the resin,” Wilkinson said.

    During the late 1700s in England, many human cadavers used for teaching purposes came from grave robbers, who plundered cemeteries for fresh corpses or even murdered people for their bodies. Grave robbers seldom succeeded in getting the bodies of children, because grieving parents set up watch over their graves. “So it seems likely that our boy could have been murdered rather than robbed from the grave,” Wilkinson said.

    To reconstruct the boy's face, Wilkinson used the CT scan to create a computer image of the skull and then added muscles and other soft tissue using standard anatomical guidelines. Her finished image shows a blue-eyed boy (a bit of artistic license, as the eye color is unknown), with a strong, jutting chin.

    The sleuthing revealed a “story as intriguing as any Dickens novel,” says Mimi Leveque, a conservator at the Peabody Essex Museum in Salem, Massachusetts. Such reconstructions are important aspects of mummy research, she says: “They help [people] to identify with the body—before that it [just] seems like an object.”

    • * Heather Pringle is a contributing editor at Archaeology magazine.

  7. 7th World Congress On Mummy Studies

    One Sick Mummy Gets a Double Diagnosis

    1. Heather Pringle*

    Researchers found an amazingly high infection intensity of whipworm in a 200-year-old adult mummy from Piraino, Italy, according to a poster presented at the meeting.

    The tiny intestinal parasite, Trichuris trichiura, or whipworm, is a bane of children living in poor sanitary conditions in developing countries today and can cause anemia, bloody diarrhea, and occasionally death. Researchers found an amazingly high infection intensity of this parasite in a 200-year-old adult mummy from Piraino, Italy, according to a poster by a team led by graduate student Kelsey Kumm of the University of Nebraska, Lincoln.

    T. trichiura buries its tail into human intestinal walls, feeds on secretions, then sheds its eggs into the intestinal tract, where they become incorporated into feces. Kumm and colleagues identified whipworm eggs while analyzing an ancient fecal sample from a male mummy—a clergyman or member of an important family—who was buried in the crypt of Piraino Cathedral in Sicily. Conditions in the crypt were so dry that his body, and many others, were naturally mummified.

    Out of the crypt.

    Scientists take a fecal sample from a mummy in a Sicilian crypt to analyze it for clues to what ailed him.


    The man's high status apparently didn't help his health. The team calculated that 1 gram of his fecal material contained 34,529 whipworm eggs, produced by an estimated 860 to 7430 worms inhabiting his intestine, the highest infection intensity of whipworm in the archaeological record. Today an infection of 200 worms or higher is considered heavy.

    In this case, the infection was probably secondary to cancer. Radiographs of the man's skeleton revealed lesions caused by plasmacytoma, a cancer of blood plasma cells. These cells produce antibodies and are integral to the immune system; the cancer may have allowed the whipworms to flourish relatively unchecked. “His immune system was really weakened,” Kumm says. That conclusion seems “absolutely valid,” says paleopathologist Guido Lombardi of Cayetano Heredia University in Lima, although he notes that “there is no way to test the immunity of mummies directly.”

    A second study, led by graduate student Sara LeRoy-Toren of the University of Nebraska, Lincoln, examined plant remains from the same coprolite. Before the man's death, he apparently consumed a mash of ground-up grapes and grape stems, which may have been part of a medicinal treatment. Recent studies have shown that chemical compounds in grapes possess anticancer properties, inhibiting the spread of the disease, LeRoy-Toren says—so the grape mash may have been part of a last-ditch medical treatment.

    • * Heather Pringle is a contributing editor at Archaeology magazine.

  8. 7th World Congress On Mummy Studies

    For Best Ticket to the Afterlife, Pay Up

    1. Heather Pringle*

    Bioarchaeologists reported at the meeting that only elite members of ancient Egyptian society consistently benefited from all the tricks of the embalmers' trade, thereby boosting their chances of a pleasurable afterlife.

    Egyptologists have often suggested that ancient embalmers mummified each client the same way for some 3000 years. But the real picture was far more complicated, reported bioarchaeologist and Ph.D. student Andrew Wade of the University of Western Ontario in London, Canada. Only elite members of ancient Egyptian society consistently benefited from all the tricks of the embalmers' trade, thereby boosting their chances of a pleasurable afterlife.

    Ready for the afterlife.

    A three-dimensional image of an Egyptian mummy helped show how embalmers prepared it.


    Mummification was done to prepare the dead for the next world, preserving their bodies and ridding them of disease. It was “a transformative process making the deceased a pure being free of disease, injury, and deformity,” Wade said in his talk. Part of the job included removing the lungs, liver, stomach, and intestines, probably so these vital organs could be specially preserved by magical spells and placed in nearby jars.

    Wade and University of Western Ontario bioarchaeologist Andrew Nelson analyzed computed tomography scans and scientific literature on 150 mummies dating from the Old Kingdom (some 4600 to 4100 years ago) to the Roman period. They found that during the time of the Old Kingdom, embalmers reserved evisceration for elite males and extended it to commoners only some 1000 years later.

    Embalmers also often removed the brain, which Egyptians considered to be simply a source of mucus, apparently to boost respiratory health in the afterlife. Wade and his colleagues analyzed 125 mummies and found that among 31 elite individuals, 75% had their brains removed. But only 60% of commoners got that treatment. In death, as in life, Egypt's elite got preferential treatment.

    • * Heather Pringle is a contributing editor at Archaeology magazine.