Around the World
- 1 - New Orleans, Louisiana
- Research, Restoration Get Share of Record BP Oil Spill Fine
- 2 - Brussels
- Scientists Lobby E.U. Presidents to Prevent Budget Cuts
- 3 - Mumbai, India
- Vultures Soar in India
- 4 - Mountain View, California
- Millions of Dollars for Extraterrestrial Hunt
- 5 - Sacramento
- Cap-and-Trade for California
- 6 - Geneva, Switzerland
- Major Changes Afoot at Global Fund
New Orleans, Louisiana
Research, Restoration Get Share of Record BP Oil Spill Fine
Environmental restoration projects and scientific research will get a major windfall from a 15 November decision by oil giant BP to pay a record $4 billion to settle U.S. criminal charges related to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. More than half of the total, $2.4 billion, will go to a congressionally chartered foundation for ecological restoration projects along the Gulf Coast. Another $350 million will go to the U.S. National Academy of Sciences to establish a 30-year research effort focused on reducing the risk of future spills and improving environmental monitoring. The payments are unlikely to be BP's last; the company still faces other penalties, including up to $25 billion in civil fines for oil pollution.
Scientists Lobby E.U. Presidents to Prevent Budget Cuts
A delegation led by Nobel laureates Tim Hunt and Jules Hoffmann on 15 November met with the European Union's three presidents—European Parliament President Martin Schulz, European Council President Herman Van Rompuy, and European Commission President José Manuel Barroso—to lobby them to spare research funding from looming cuts in the European Union's budget.
A growing chorus of scientists and research organizations across Europe has been arguing that research funding should be protected from cuts because it offers a path out of the crisis and a way to strengthen the European Union's economy in the long term.
“They're on our side, no question about that,” Hunt says, referring to the three presidents. “Van Rompuy said he'd do his best to protect [research funds]” in upcoming negotiations, Hunt adds. Van Rompuy's support may matter most in the short term, as the European Council—the body representing the governments of the member states—has the most power over spending. http://scim.ag/EUSciBdgt
Vultures Soar in India
There's good news for South Asian vulture populations, possibly thanks to a 2006 ban on veterinary use of the painkiller diclofenac, used to treat livestock. Researchers surmised that the drug induced kidney failure in vultures that ingested it while feeding on dead livestock recently treated with the drug. A 2011 population survey of the oriental white-backed vulture, long-billed vulture, and slender-billed vulture found a slowdown in the rapid decline seen in all three species since the early 1990s, researchers report online this month in PLOS ONE. The team notes that this is the first sign of recovery for these endangered birds.
The results are encouraging, said conservation scientist and study co-author Richard Cuthbert of the United Kingdom's Royal Society for the Protection of Birds in a statement. But he added: “A lot of hard work still remains to ensure that the small surviving populations can now begin to recover across South Asia and other toxic veterinary drugs do not cause similar impacts.”
Mountain View, California
Millions of Dollars for Extraterrestrial Hunt
A generous gift has breathed new life into the search for extraterrestrial intelligence. The SETI Institute in Mountain View, California—whose future was looking bleak a year ago because of a lack of funding—has received a $3.5 million donation from Franklin Antonio, co-founder and chief scientist of Qualcomm. The institute will use the new money to improve the sensitivity of its Allen Telescope Array, which searches the cosmos for signals from alien civilizations.
Cap-and-Trade for California
The cap-and-trade system that California launched last week to cut greenhouse gas emissions is the first such comprehensive scheme in the United States. It began with an auction on emissions permits for the electricity sector, the first to be regulated. The sale includes a price floor of $10 per ton of carbon dioxide to prevent a crash of emissions prices. The system will expand in 2015 to cover transportation, commercial, and residential fuels, regulating 85% of California's total greenhouse gas pollution.
The system was set up as part of a landmark 2006 state law and survived a voter referendum to suspend it in 2010. Other emissions control schemes already in place include one established in Europe in 2005—which covers electricity and industry—and in the northeastern United States, which covers only electricity.
Major Changes Afoot at Global Fund
In dizzying but unrelated decisions last week, the board of the Global Fund to Fight AIDS, Tuberculosis and Malaria hired a new executive director, fired its inspector general, and made a controversial decision about financing malarial drugs. The fund, which has spent $23 billion since 2002 to finance treatment and prevention of these three diseases in resource-limited countries, announced on 15 November that Mark Dybul would take the helm. Dybul formerly ran the President's Emergency Plan for AIDS Relief, a multibillion-dollar program financed by the U.S. government. John Parsons, the fund's inspector general for the past 5 years, was dismissed for “unsatisfactory” work, the board said. And finally, the board decided to fold the Affordable Medicines Facility-malaria (AMFm)—a controversial program that aims to improve access to more effective malarial medicines by enlisting the private market—into the fund's regular activities. Backers of AMFm say the move threatens the scheme's survival. http://scim.ag/_GFund
Computer Graphics, Cellular Processes Win Kyoto Prize
American computer scientist Ivan Sutherland (top) and Japanese biologist Yoshinori Ohsumi (bottom) have won the Kyoto Prize, which encourages a balance between scientific progress and spiritual depth. The prize, administered by the Inamori Foundation, was awarded for their lifetime achievements. Sutherland, 74, the “Father of Computer Graphics” now at Portland State University in Oregon, won the advanced technology prize for developing progenitors of the graphical user interfaces now ubiquitous in many devices, such as smart phones and personal computers.
Ohsumi, 67, of Tokyo Institute of Technology, won the basic sciences prize for unraveling the mechanisms and demonstrating the significance of autophagy, the phenomenon by which a cell degrades and recycles its own components. Autophagy plays a central role in cell growth, development, and homeostasis. Understanding autophagy could lead to future treatments for neurodegenerative diseases and cancer.
Each laureate received a medal, a diploma, and about $630,000 at a ceremony in Kyoto on 10 November.
Join us on Thursday, 29 November, at 3 p.m. EST for a live chat on the imminent “end of the world.” http://scim.ag/science-live
Double Whammy for Threatened Salamander
The threatened California tiger salamander is losing ground on its native turf. This black and yellow-spotted amphibian interbreeds with the introduced barred tiger salamander. Hybrid larvae outcompete the native young, making the smaller natives more vulnerable to environmental insults, says evolutionary ecologist Maureen Ryan, of the University of Washington, Seattle. One month into a study on the effects of habitat and hybrid-native interactions on salamander survival, all of the native tiger salamander larvae and about half of the hybrid larvae suddenly died in four of the six ponds containing the experiments. Ryan and colleagues ruled out fungal and viral infections and strongly suspect pesticide runoff killed the salamanders' invertebrate food supply, starving them, they reported online 9 November in Conservation Biology. The more hybrids in the enclosures, the smaller the natives were, they noted. The team speculates that the natives weren't big enough to switch to larger prey, such as tadpoles, when the invertebrates disappeared. Further study would be needed to verify the pesticide connection, Ryan adds.
- Animal Domestication
In Search of the Wild Chicken
- Andrew Lawler
Researchers are melding genetics and archaeology to close in on the origin of the world's most common bird—and potentially help protect a major source of animal protein.
In the 1950s, bird hunters in the southern United States were eager to bag more exotic prey than quail, and so their representatives in Washington agitated for the introduction of foreign varieties. A U.S. Fish and Wildlife Service biologist dutifully went to a remote area in India's Himalayan foothills and collected dozens of red jungle fowl, a colorful, shy, and tasty wild bird that also happens to be the primary progenitor of today's domestic chicken. Bred at research stations across the South, nearly 10,000 of the birds were released in the 1960s. They failed to thrive, and the program introducing an alien species was quietly cancelled. The few remaining penned jungle fowl were slated for slaughter in 1969.
But a young ecologist named I. Lehr Brisbin rescued five birds. The biologist who had originally imported them warned him that someday these birds might be the last ones left. “I didn't understand what he meant at the time,” recalls Brisbin, who works at the University of Georgia's Savannah River Ecology Laboratory in Aiken, South Carolina. “Now I do.” Over the intervening decades, South Asia's wild red jungle fowl has suffered from development and crossbreeding with village chickens, while Brisbin's flock quietly flourished in an aviary in Alabama. Today, there are more than 100 birds, carefully isolated from other varieties, that may be among the closest living wild ancestors of the modern chicken.
Their genes, and those of other isolated populations, are now being sequenced (see sidebar, p. 1022) as part of a larger effort to understand the world's most common bird and biggest source of animal protein. In 2009, Americans ate 36 billion pounds of chicken, and the numbers keep growing, especially in developing countries in Asia and Africa. That importance is highlighted by the fact that the chicken was the first farm animal to have its genome published, back in 2004. Since then, the proliferation of factory farms, mass bird deaths from avian influenza, and dwindling diversity in chickens have raised concerns about this critical source of food.
A key thrust of research in the past decade has been to track the genetic changes that turned a remarkably shy creature into today's meat-and-eggs dynamo, with an eye to protecting and improving breeds. But this research has also given scientists the opportunity to unravel a long-standing mystery that fascinated Charles Darwin: Where, when, and how was the chicken domesticated?
Researchers agree that the red jungle fowl gave rise to the barnyard chicken somewhere in South Asia. But they agree on little else. Some contend that domestication took place 8000 years ago; others suggest that tame chickens are only 4000 years old. Some say the bird was domesticated only once; others look to several independent centers of domestication. And since Darwin's day, scholars have disputed whether the three other jungle fowl subspecies contributed to the modern bird. There isn't even accord over whether the truly wild red jungle fowl remains numerous or has long gone extinct, leaving only mixtures of wild and domesticated birds. “There has been more noise than signal,” says Greger Larson, an archaeologist at Durham University in the United Kingdom.
The sudden surge in chicken studies across several disciplines may soon help answer these fundamental questions, however. One recent paper claims that two subspecies contributed to today's chicken, while another paper published this week suggests that the bird was domesticated separately in several regions. Researchers are tracking red jungle fowl populations across South Asia and searching for older specimens in museums for DNA sequencing. Archaeologists, meanwhile, have begun to extract DNA from ancient chicken bones to determine the genetic profile of prehistoric barnyard birds. “Now we are getting the data,” Larson says. “And we may be getting to the answers.”
Identifying the chicken's wild cousins and preserving their genetic diversity may one day prove critical for improving the stock, some researchers say. Genes from wild birds may help breed birds resistant to avian influenza and other illnesses, for example. “This is the most important bird to humans,” says A. Townsend Peterson, an ornithologist at the University of Kansas, Lawrence. “And we can potentially make chickens better.”
The indispensable bird
Humans have been shaping the chicken for millennia. Darwin's grandfather Erasmus was one of the first to suggest that the red jungle fowl was the ancestor of the chicken, Gallus gallus domesticus. His grandson, who studied chickens as he formulated his theory of evolution, backed this up with detailed observation of the jungle fowl's physical characteristics and postulated that the chicken was domesticated in India and then spread around the world. But he also complained that “sufficient materials do not exist for tracing the history” of the bird.
The red jungle fowl—Gallus gallus—ranges from the western foothills of the Himalaya Mountains to the tip of Sumatra (see map, p. 1022). Unlike modern-day chickens, all roosters sport elaborate plumage, the females lack a comb, and both genders have thin, dark legs and can fly considerable distances. The fowl is also generally half the size of a White Leghorn domesticated chicken, but it can produce fertile offspring with domestic chickens.
Domestication couldn't have been easy given the bird's extremely shy nature. However, its habits ultimately made it a natural domesticate. It lives by day on the forest floor, eating insects, seeds, and fruits, and it nests in trees at night to avoid its myriad predators. Life spent pecking in a barnyard during the day and safe in a coop at night is not so removed from the fowl's natural condition, says anthropologist Naomi Sykes of the University of Nottingham in the United Kingdom. Once domesticated, the chicken proved remarkably versatile. It could eat almost anything and provided not just meat and eggs but medicines, sacrifices for religious ritual, and entertainment in the form of cockfighting. Humans carried the easily portable bird around the world.
How this began remains controversial. Archaeological finds of chicken bones were rare until recently. Bones and artifacts at Indus River valley sites south of the red jungle fowl's range revealed domesticated birds by 2000 B.C.E., bolstering Darwin's view of a single domestication in India. Then a hotly disputed Chinese find in 1988 pushed the date back to 6000 B.C.E.
The advent of sequencing tools in the 1990s promised a new line of evidence that went beyond physical characteristics. The results, however, have only heightened the controversy. A draft of the chicken genome, for example, isn't enough to trace the bird's evolution: Researchers need ancestral birds for comparison. Geneticists first used mitochondrial DNA (mtDNA) to trace the female line of the species back to its origin. Akishinomiya Fumihito, an ornithologist and prince in Japan's royal family, extracted sections of mtDNA from Thai red jungle fowl and asserted in a 1994 paper that the findings suggested a single domestication in Thailand. Eight years later, another team used mtDNA from native Chinese chickens to support that idea.
In 2006, however, a team led by Yi-Ping Liu of China's Kunming Institute of Zoology found nine separate clades—that is, groups descended from a common ancestor—in the mtDNA of a large sample of wild and domestic modern birds. The distribution of the clades suggests a distinct and separate expansion of lineages in southern China, Southeast Asia, and the Indian subcontinent, supporting a multiple origins theory. Another team published a study this week in Heredity based on nuclear DNA, which is not limited to the maternal line, supporting that view.
“It shows the complex history of the chicken,” says Michèle Tixier-Boichard, a geneticist at the French National Institute for Agricultural Research in Paris, who was not part of the Heredity research but is familiar with the results. “And their sampling is impressive.”
The implications are important for capturing genetic diversity, because if the chicken really did have multiple origins, researchers will have to carefully sample wild birds across many areas. The find also suggests that early peoples were operating largely independently, and that new technologies were homegrown rather than diffused.
But others insist that the old debate is far from over. “We need to reconcile all the data,” says Olivier Hanotte, a geneticist at the University of Nottingham. He favors a single origin in northern Southeast Asia, based on the enormous diversity of chicken breeds there.
Whether domestication originally diffused from a single region or from multiple points, other genetic evidence suggests that more than one subspecies contributed to the modern chicken along the way. In 2008, Larson, geneticist Leif Andersson of Uppsala University in Sweden, and others claimed “the first conclusive evidence for a hybrid origin of the domestic chicken.” The results made headlines for contradicting Darwin's assertion that the red jungle fowl was the sole ancestor. Using single-nucleotide polymorphisms (SNPs) in nuclear DNA, the team found that the chicken's yellow skin allele likely comes from the grey jungle fowl, not the red. Domestication, they concluded, had many stages—and continues today.
Despite the power of these genetic approaches, some researchers say that decades of studies comparing red jungle fowl and modern birds may be fatally flawed, because wild and domesticated populations have mixed across South Asia for millennia. “The chicken is like a sponge, sucking up genes wherever humans take them,” Larson says. Travelers, hunters, and merchants carrying hens for eggs and meat and breeding them with wild or hybrid roosters—all likely scenarios—would, over millennia, have muddied the wild fowl's gene pool.
Thus, no one knows the genetic makeup of a pure wild red jungle fowl. Biologist Sambandam Sathyakumar of the Wildlife Institute of India in Dehradun, near where Brisbin's birds were collected a half-century ago, says genetic studies show that more than 95% of their birds are “relatively pure.” But Brisbin and other researchers note ominous signs of morphological and behavioral changes in the fowl. For example, biologists have mapped the gradual loss of the male red jungle fowl's eclipse plumage—a long black feather across the middle of his back and slender red-orange plumes on the rest of his body—which is absent in chickens. This plumage started to vanish in wild Southeast Asian birds a century ago and was gone in most Indian birds by the 1960s. And many red jungle fowl hens in zoo collections—often the source of scientific samples—have combs, though the purely wild birds do not. “All the work done to date is inconclusive, and our colleagues around the world have not been careful about the provenance of their material,” Peterson says. “Our studies have been done without any idea what is a pure red jungle fowl.”
Brisbin and Peterson hope that sequencing the birds brought from India to the United States in the 1960s, now being done by Andersson's lab, may create a genetic baseline for the wild bird, as well as provide “a reservoir of potentially invaluable genetic variation,” says Tomas Condon, a biologist who studied at Georgia Southern University in Statesboro and researched the history of Brisbin's flock. Others are combing museum collections for DNA from pre-1900 birds that might be of purer strain. But some warn that the outcome could prove disappointing. “I'm not convinced [Brisbin's birds] are wild,” says Hanotte, who also has samples from the birds but has not yet published a sequence. “I think they are related to domestic birds in Southeast Asia.” He and Larson believe that introgression has been going on for millennia and that the search for a pure wild bird, even if the genetic material is more than a century old, may prove fruitless.
Ancient chicken bones could provide data that circumvent the complexities of today's birds. But information on the chicken's prehistory is remarkably scant. “Until 20 years ago, no one bothered to analyze chicken bones,” says Melinda Zeder, an archaeozoologist at the Smithsonian Institution's National Museum of Natural History in Washington, D.C. “Finally, that is starting to change.”
Larger species like sheep and goat left behind more evidence, and they were domesticated in the Middle East, an area closely studied by archaeologists. By contrast, chicken bones are hard to find and the birds were domesticated in a region largely untouched by excavators' spades. “The chicken has been woefully neglected,” Larson says. He and others have begun to use fine-meshed sieves to recover even tiny bone fragments, an effort that is paying off, but only after many false starts.
A stunning 1988 claim of very ancient domesticated chicken bones in central China, for example, implied that the bird was carried 2000 kilometers north of the jungle fowl's range as early as 6000 B.C.E. That suggested at least two centers of domestication, the Indian subcontinent and China. But these and many other bones have been seriously misdated, says paleozoologist Joris Peters of Ludwig Maximilian University of Munich in Germany. He has embarked on a laborious effort to ascertain the age of ancient bird bones around the world, and his early conclusions offer a sobering lesson. “The problem with chicken bones is that they move around,” Peters says. Small and lightweight, they easily slip lower in the soil—appearing to be older than they really are—and rodents and other animals can readily shift them around.
That appears to be the case with the Chinese chickens. After cursorily examining the evidence last year in Beijing, Peters says the bones more likely date to the settlement layer of the Han Dynasty—6 millennia later than claimed. By then, the chicken had already spread across both Asia and Europe. Although chicken bones may move around in sediment, they can be carbon-dated directly, and Peters is doing just that, starting with a collection of ancient Near Eastern and Greek bones. Preliminary results suggest they are centuries younger than once thought.
Ultimately, researchers hope to get ancient DNA from well-dated bones. But “replicable DNA has been as rare as hen's teeth,” Zeder says, thanks to contamination issues and tropical climes that degrade DNA. One team recently claimed to have mtDNA from an ancient Polynesian chicken bone in Chile—a dramatic find that would prove Polynesians reached the Americas before Columbus—but the find has been questioned as possibly contaminated (Science, 11 June 2010, p. 1344). Techniques are improving, however. Larson hopes to sequence Thai bones dated to as early as 1500 B.C.E. It's a long shot, because the DNA is likely to have degraded in the humid Thai climate. “But we don't need a huge number of successes,” he says. “Just one will tell us a lot.”
Other genetic studies are beginning to identify traits involved in domestication. For example, a 2010 paper in Nature reported the sequence of more than 7 million SNPs in the genome of the chicken and the red jungle fowl. The team, led by Uppsala's Carl-Johan Rubin and including Andersson as a co-author, pinpointed a thyroid-stimulating hormone receptor that is shared by all domesticated birds but not the wild fowl, and presumably spurs growth. “This shows what traits were being selected” during domestication, says Wes Warren, a geneticist with Washington University in St. Louis.
But Hanotte notes that growing genetic evidence suggests small populations in the early phase of domestication, which may point to cockfighting as an initial driver rather than eggs and meat. Even today the red jungle fowl is known as a small but fierce fighter in South Asia. In Vietnam, for example, trapping the bird is an illegal but widespread practice. A single cock can net well over $100.
Such pressures could soon render the truly wild bird extinct, if it is not already. That worries biologists, who note that conservationists don't have the jungle fowl on their radar. There is no guarantee that saving the red jungle fowl and its wild genes will pay off in the future, but they insist that it would be tragic to let the opportunity slip away. For Condon, the young biologist, the genetic information in truly wild fowl could kill two birds with one stone, unraveling the chicken's past while potentially ensuring its future. “This is the most important bird in the world,” he says. “We need to preserve the original.”
- Animal Domestication
From Farmyard to the Lab
- Andrew Lawler
Chinese biologist Jianlin Han is attempting to breed better red jungle fowl to benefit the rural poor and gather a massive data set to understand the genetic underpinnings of the domestic chicken.
SON LA, VIETNAM—On a tidy farm in the mountains of northwest Vietnam, Chinese biologist Jianlin Han expertly grabs a nervous red jungle fowl recently captured in this region's quickly disappearing forest. The bird—which sports a long and dangerously sharp spur—is part of Han's hands-on effort to breed better animals to benefit the rural poor, while at the same time gathering a massive data set to understand the genetic underpinnings of the domestic chicken.
Han, who grew up raising chickens in rural China, is as comfortable in the lab as in the barnyard. Although the chicken's genome was sequenced in 2004, traditional livestock research around the world has been decidedly low-tech. Different chicken varieties are still described by physical traits and behavior rather than by genetic heritage. Researchers like Han, trained in genetics but interested in agricultural applications, are increasingly using DNA tools to see how genotype affects a bird's phenotype. They also hope that these data will help them get at fundamental questions such as when and where the chicken was domesticated (see p. 1020).
The chicken, which grows quickly and is the most intensely bred of domestic animals, provides an intriguing model for understanding those issues, says Han, who works for the International Livestock Research Institute based in Nairobi but spends most of his time in his Beijing lab and in the field across South Asia. He recently took a bone-jarring 8-hour trip from Hanoi to check up on an experiment to breed the red jungle fowl—generally acknowledged as the primary progenitor of the chicken—with both local and foreign breeds. The goal is to produce a domesticated chicken that caters to local tastes while providing more meat and eggs. Han is also investigating the unusually high number of local varieties found in surrounding villages—many more than elsewhere in South Asia—which may be a hint that the chicken was originally domesticated in this rugged area.
Han has an ambitious plan to catalog the genetic makeup of today's jungle fowl, charting its diversity in different regions and also revealing whether it includes genes from domestic chickens. In the past 7 years, he and collaborators around the world have sampled blood from more than 200 birds belonging to the four types of jungle fowl, including more than 120 red jungle fowl, from Pakistan, Bangladesh, Indonesia, Vietnam, and China. Those from China's Hainan Island—which harbors a red jungle fowl population that has been largely isolated from domestic varieties—could prove particularly intriguing, Han says.
He and his colleagues have analyzed the birds' mitochondrial DNA as well as microsatellites: short, repeating sequences in the nuclear DNA that could reveal what parts of the chicken genome differ from that of the jungle fowl. Starting early next year, he hopes to analyze single-nucleotide polymorphisms in selected parts of the genome. “We won't be the first to do this with the red jungle fowl, but we will be the first to use this large number of samples,” he says. Han wants to compare wild birds from a wide array of regions to see the larger picture of genetic change among the many subspecies in order to gauge the impact of domestication on specific parts of the genome. “Jianlin's brute-force approach definitely has its merits,” says archaeologist Greger Larson of Durham University in the United Kingdom. “I suspect we can't possibly know what all the variation is out there unless you go and sequence a ton of stuff.” Geneticist Olivier Hanotte of the University of Nottingham in the United Kingdom agrees, though he adds that ultimately full-genome sequencing of the jungle fowl—a far larger, expensive, and complicated task—would provide more definitive answers. But no such grand plans are in the works at the moment.
Han is also curious about what happens when chickens go feral. Natural selection reasserts itself when humans no longer make breeding decisions or provide regular food and protection. “This will help us understand how the genome works, and how plastic it is,” Han says. “This is the most fundamental biological question.” The lowly chicken may one day provide humans with more than just a cheap joke or a fast meal.
- Public Health
Making Sense of a Senseless Act
- Mara Hvistendahl
Research from Asia is overturning long-held notions about the factors that drive people to commit suicide.
SHANGHAI, CHINA—Mrs. Y's death would have stumped many experts. A young mother and loyal wife, the rural Chinese woman showed none of the standard risk factors for suicide. She was not apparently depressed or mentally ill. Villagers said she exuded happiness and voiced few complaints. But when a neighbor publicly accused Mrs. Y of stealing eggs from her henhouse, the shame was unbearable. Mrs. Y rushed home and downed a bottle of pesticide. “A person cannot live without face,” she cried before she died. “I will die to prove that I did not steal her eggs.”
Decades of research in Western countries have positioned mental illness as an overwhelming predictor of suicide, figuring in more than 90% of such deaths. Another big risk factor is gender: Men commit suicide at much higher rates than women, by a ratio of nearly 4 to 1 in the United States, according to the U.S. Centers for Disease Control and Prevention. Other common correlates include city life and divorce. But in China, says Jie Zhang, a sociologist at the State University of New York, Buffalo State, the case of Mrs. Y is “a very typical scenario.”
Zhang oversaw interviews with Mrs. Y's family and acquaintances while researching the prevalence of mental illness among suicide victims aged 15 to 34 in rural China. Through psychological autopsies—detailed assessments after death—Zhang and coauthors found that only 48% of 392 victims had a mental illness, they reported in the July 2010 issue of the American Journal of Psychiatry. An earlier study of Chinese suicide victims put the prevalence of mental disorders at 63%—still nowhere near as high as accepted models of suicide prevention would predict. Meanwhile, other standard risk factors simply don't hold true, or are even reversed, in China. Chinese women commit suicide at unusually high rates; rural residents kill themselves more frequently than city dwellers do; and marriage may make a person more, rather than less, volatile.
Such differences matter because China accounts for an estimated 22% of global suicides, or roughly 200,000 deaths every year. In India, meanwhile, some 187,000 people took their own lives in 2010—twice as many as died from HIV/AIDS. By comparison, the World Health Organization (WHO) estimates that suicides in high-income countries total only 140,000 a year. Suicide rates in Japan and South Korea, however, are similar to China's (see p. 1026), suggesting that this is a regional public health issue. And yet suicide in Asia is poorly understood. “Suicide has not gotten the attention it deserves vis-à-vis its disease burden,” says Prabhat Jha, director of the Centre for Global Health Research in Toronto, Canada.
Emerging research from developing countries like China and India is now filling that gap—and overturning prevailing notions. “The focus of the study of suicide in the West is psychiatry,” Zhang says. While mental illness remains an important correlate in Asia, he says, researchers may learn more from a victim's family, religion, education, and personality. New findings, Zhang says, suggest that some researchers may have misread correlation as causation: In both the East and the West, “mental illness might not be the real cause of suicide.”
Reliable data on suicide across Asia were once maddeningly scarce. In Thailand until 2003, there was no requirement that the reported cause of death be medically validated—a flaw that rendered the country's suicide data inaccurate. In India, suicide is a crime, which means it often goes unreported. But the Thai government now has a more accurate reporting system for mortality figures, while Indian researchers are benefiting from the Million Death Study, an effort to catalog causes of death for 1 million Indians in a 16-year survey relying on interviews with family members (Science, 15 June, p. 1372). The study has already produced a disturbing revelation about reported suicide rates. “When we compare our data with police reports, you find undercounts of at least 25% in men and 36% in women,” says Jha, the study's lead investigator.
New insights from China are particularly instructive. Because suicide carries a stigma, the Chinese government withheld data on the topic until the late 1980s. When information finally came out, it quickly became clear that the country had a serious problem. In 1990, for example, the World Bank's Global Burden of Disease Study estimated there were 343,000 suicides in China—or 30 per 100,000 people. The U.S. rate for the same year was 12 per 100,000.
But other reports gave different figures, prompting a debate on sources. WHO's extrapolated total was based on data that China had reported from stations covering only 10% of the population, skewed toward urban residents. As researchers focused on the problem, they arrived at more reliable figures—but also unearthed more mysteries. In an analysis in The Lancet in 2002, a group led by Michael Phillips of Shanghai Mental Health Center and Emory University School of Medicine in Atlanta estimated that from 1995 to 1999, Chinese women killed themselves more frequently than men—by a ratio of 5 to 4. “There was originally disbelief about the very different gender ratio in China,” Phillips says, although later it was accepted.
Today, the suicide sex ratio in China is roughly 1 to 1, still a significant departure from the overall U.S. male-to-female ratio of 4 to 1. In India, the male-to-female suicide ratio is 1.5 to 1, although in the 15 to 29 age group it is close to equal. And yet, WHO estimates the global sex ratio at three men to one woman. (With colleague Cheng Hui, Phillips recently used Chinese and Indian figures to lower that estimate to 1.67 to 1.) Among young adults in India, suicide is second only to maternal mortality as a cause of death for women, according to the Million Death Survey.
In both China and India, cases like Mrs. Y's involving no apparent mental illness are common. In India, suicide is most prevalent among teenagers and young adults—the cohort that is entering the workforce, marrying, and facing new life stresses. This contrasts with the Western pattern of high suicide rates among the middle-aged, suggesting that although “there might well be some underlying psychiatric conditions, the main drivers of [suicide in India] are probably chiefly social conditions,” Jha says. While cautioning that detailed psychological autopsies are still needed in India, he says, “it's a reasonable assumption that many of these young folks are not mentally ill.”
Convincing researchers outside Asia may prove an uphill battle. Matthew Miller, a suicide researcher at the Harvard Injury Control Research Center in Boston, says there may be differences in the recognition, reporting, and incidence of mental illness in Asia. Phillips, who has worked in China for over 20 years, says that underdiagnosis is a problem, and that “many Western researchers still believe that we are just missing cases.” But he rejects that explanation. Even accounting for underdiagnosis, he says, the finding of a lower rate of mental illness among suicide victims has held up in multiple studies. Many Chinese suicide victims, he adds, are “most certainly severely distressed, but they don't meet the criteria of a formal mental illness.”
Assuming that suicide risk is shaped by different factors in Asia, researchers are striving to uncover the roots. One clue may lie in the high proportion of unplanned Chinese suicides. In a 2002 survey of 306 Chinese patients who had been hospitalized for at least 6 hours following a suicide attempt, Phillips and colleagues found that 35% had contemplated suicide for less than 10 minutes—and 54% for less than 2 hours. Impulsiveness among suicide victims in Asia “tends to be higher than in the West,” says Paul Yip, director of the Hong Kong Jockey Club Centre for Suicide Research and Prevention at the University of Hong Kong and one of the authors of a recent WHO report on suicide in Asia. Although impulsive personality traits are sometimes linked to illnesses like bipolar disorder, studies in China have not uncovered full-fledged personality disorders in impulsive suicide victims.
In a tragic twist, impulsive victims in Asia tend to favor highly fatal methods. After interviewing family members and friends of 505 Chinese suicide victims, Kenneth Conner, a psychiatric researcher at the University of Rochester Medical Center in New York, and colleagues reported in 2005 that those who had ingested pesticides were more likely to have acted rashly than were those who used other methods such as hanging or drowning. Pesticides are a leading cause of suicide death in China and India, and the cause of roughly half of suicides worldwide. Pesticides may also explain Asia's unusual suicide sex ratio, Jha says. In the West, women attempt suicide just as frequently as men do, but they tend to down sleeping pills—and often survive.
The trends in Asia point to a need for innovative prevention strategies. Zhang believes efforts should focus less on mental illness and more on “educating people to have realistic goals in life and teaching them to cope with crisis.” Front and center should be universities and rural women's organizations, both of which already have active suicide prevention programs in China, he says. Such community-based approaches appear to have been effective in Hong Kong, Yip says. Over the past decade, the territory has rolled out programs for schoolchildren on dealing with stress and outreach groups for older adults. Its suicide rate has fallen 27% since 2003.
But resources in many Asian countries are limited. The vast majority of cities in China and India still do not have 24-hour suicide prevention hotlines. That may make what scholars call means restriction—reducing access to tools commonly used in suicide—a better goal. In Sri Lanka, pesticides once accounted for two-thirds of suicide deaths. Then in 1995, the government took steps to ban the most toxic pesticides. The suicide rate plummeted by 50% in the following decade.
The varying degrees to which mental illness and suicide correlate in East and West may ultimately be beside the point, argues Zhang, who believes a third factor may be the trigger in both regions. Strain theory, which posits that societal pressures, rather than inborn traits, contribute to crime, can help explain suicide, he believes. “Psychological strains usually precede a suicidal behavior, and they also happen before an individual becomes mentally ill.”
When a person is pulled by two or more conflicting pressures, Zhang says, as with “a girl who receives Confucian values at home and then goes to school and learns about modern values and gender equality,” she may be more prone to suicide. Other situational stresses may include a sudden crisis faced by a rural woman lacking coping mechanisms—such as the case of Mrs. Y—or an incident that forces a young man to confront a gap between his aspirations and reality. Zhang found that strain theory held up for his study subjects in rural China. He plans to probe whether it also applies to older Chinese.
Ultimately, Zhang hopes to test strain theory on Americans. The U.S. National Institutes of Health “spends millions and millions of dollars every year on treating mental illness to prevent suicide,” he says. “But no matter how much money we spend, how many psychiatrists we train, or how much work we do in psychiatric clinics, the U.S. suicide rate doesn't decrease.” It has hovered around 10 to 12 suicides per 100,000 people since 1960.
Such research may be the tip of the iceberg when it comes to debunking long-held ideas about behavior disorders. Alcoholism is another area ripe for exploration, Cheng says: The profile of alcoholics in China contrasts sharply with that in the West. Because of social pressure to drink, Chinese alcoholics are far more likely to be working and married than American counterparts, who are often unemployed and divorced, she says. Suicide, Cheng muses, “is just another example of how environment can change behavior.”
- Public Health
Korea Tackles a Mushrooming Problem
- Dennis Normile
Rapid socioeconomic changes, a burgeoning elderly population, and cultural influences may all play roles in the surge in suicide in Korea, both in South Korea and elsewhere in the region.
After a popular South Korean actress hung herself on 2 October 2008, news reports included lurid details about the act. Choi Jin-sil became a grim role model: Suicides jumped 66% in South Korea that month and continued at high rates for months. Young hanging victims accounted for most of the increase.
In the gloomy realm of suicide research, South Korea stands out. “Korea is unusual in the high number of young women killing themselves,” says Ha Kyooseob, a psychiatrist at Seoul National University. Another eye-catching pattern is a high suicide rate among the elderly. But perhaps the most alarming feature about the trend is how quickly the suicide rate has accelerated, from fewer than 10 suicide deaths per 100,000 people in 1990 to 31.2 per 100,000 in 2010—the world's second-highest rate after Lithuania and nearly triple the average of advanced industrialized nations. Suicide leapt from the 10th most frequent cause of death in South Korea to fourth; it is now the leading killer of those aged 10 to 39.
“Nobody knows the exact cause of the surge in suicide in Korea,” says Park Jong-Ik, a psychiatrist at Kangwon National University in Chuncheon. But there are hints that rapid socioeconomic changes, a burgeoning elderly population, and cultural influences all play roles, both in South Korea and elsewhere in the region. For example, China and India also have high rates of suicide among young women. And, as in South Korea, suicide rates rose sharply as economies grew in Japan, Hong Kong, and Taiwan. With neighbors facing similar challenges, “there may be something that could be learned” from the South Korean experience, says Wang Xiangdong, a psychiatrist who heads mental health efforts for the World Health Organization's Western Pacific office in Manila.
Research on suicides in the West may not shed much light on the Asian experience (see p. 1025). In North America and Europe, men take their own lives two to three times more often than women do. But in South Korea, suicide rates of men and women in their 20s and 30s are nearly the same. Ha blames this on the popularity of hanging, which more often results in death than wrist-slashing or pill overdoses—the preferred methods of women in the West. Ha believes that hanging is common because it has been used by most of the dozen or so entertainers who have killed themselves in the last decade.
A particularly disturbing trend in South Korea is the rise of suicides among the elderly (see graph). It coincides with the disintegration of support networks in rural areas as young people flock to the cities. Rural South Koreans who want to do away with themselves have ready access to pesticides. Last December, the government banned sales of Gramoxone, one of the most lethal pesticides. That could halve the roughly 3000 deaths each year attributed to pesticides, Ha says.
In addition to mental illness, South Koreans and even police statistics cite job loss, financial difficulty, academic pressure, and physical illness as factors behind suicides. Ha, however, wanted to base interventions on better evidence, so in 2010 he organized the country's first professional survey of suicide-attempt survivors. It revealed that mental illnesses, particularly depression, accounted for about one-third of unsuccessful suicide attempts. In the other two-thirds, the most commonly cited reason for attempting suicide was interpersonal conflict: children at odds with parents or teachers, school bullying, and failed relationships. In a pilot program, psychiatric nurses contact survivors during the year after a suicide attempt, a step that Ha believes has cut the rate of second attempts. To deter copycats, the media has been urged to cover celebrity suicides with restraint. And earlier this year, the government established the Korea Suicide Prevention Center to gather data and develop intervention programs.
Wang says other countries should pay heed and address suicide before it becomes a major societal problem. Given the complexity of the factors underlying suicide, he says, a community-wide response should emphasize a simple message: Suicide is preventable.