371. Climate Change: Scientists Try Assessing Impact on Species Survival

ScienceDaily, June 4, 2011 

As global temperatures rise, suitable sites for many plants and animals are shifting to cooler and higher ground. Can we predict which species will be able to move far or fast enough to keep up? A new study says the secrets to success in the face of a warming world are still elusive.

Rather than sticking around and sweating it out, some groups of plants and animals are responding to rising temperatures by migrating northward and upward to higher latitudes and elevations, studies show.

But when researchers working at the National Evolutionary Synthesis Center and the National Center for Ecological Analysis and Synthesis took a closer look at recent range shifts, they noticed a peculiar pattern: some species are migrating much farther and faster than others.

"Some species are moving well ahead of the curve, while others seem to be stuck behind," said lead author Amy Angert, a biologist at Colorado State University.

Pinpointing what sets the fastest-shifting species apart from the stragglers could help scientists and policymakers predict which species are likely to be left behind in a warming world, the researchers said.

"The species that aren't able to expand their range are the ones we need to spend more resources protecting," said co-author Sarah Gilman of Claremont McKenna College in California.

The researchers wondered if general traits such as body size, diet and lifespan might help scientists predict which species are likely to keep pace as weather warms.

To find out, they looked at data gathered from more than 400 species of birds, plants, insects and mammals known to have shifted their ranges to different degrees in the last century in response to warming.

The data set included North American birds such as house finches and bald eagles, dragonflies and damselflies in Europe, grasses and other plants in the Swiss Alps, and small mammals such as shrews, mice and chipmunks in the Sierra Nevada of California.

The species quickest to expand their range should be those that reproduce the fastest, disperse the farthest, and are the least picky about food, shelter, or mates, models predict.

To find out if predictions hold true, the researchers compiled data on how far each species had shifted, and compared it to various intrinsic features of the species themselves, such as their mode of dispersal, breeding rate, and dietary preferences.

The result? Global warming's winners and losers may be hard to predict based on broad traits related to dispersal ability or reproduction, the researchers explained.

"For each group we found one or more traits that do explain some variation in recent range shifts, but none with clear influence across all groups," wrote Angert, who studies the effects of climate change on range shifts in monkeyflowers.

One possibility is that the traits that really matter for a species' ability to move to more suitable sites -- such as temperature tolerance -- are difficult to measure or find a proxy for, the authors argue.

Another possibility is that external factors, such as habitat fragmentation and availability, may be just as important as the species themselves. Plants and animals on mountain peaks or near the poles may simply have nowhere cooler to go, the researchers explained.

The findings were published in Ecology Letters.

Other authors on the paper include Lisa Crozier of the Northwest Fisheries Science Center in Seattle, Leslie Rissler of the University of Alabama, Josh Tewksbury of the University of Washington, and Amanda Chunco of the University of North Carolina at Chapel Hill.

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by National Evolutionary Synthesis Center (NESCent), viaEurekAlert!, a service of AAAS.

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Journal Reference:

1. Amy L. Angert, Lisa G. Crozier, Leslie J. Rissler, Sarah E. Gilman, Josh J. Tewksbury, Amanda J. Chunco. Do species’ traits predict recent shifts at expanding range edges? Ecology Letters, 2011; DOI: 10.1111/j.1461-0248.2011.01620.x

370. Spiders Suffer from Human Impact

This is a tarantula (Lycosa tarantula) in Doñana.
(Credit: Samuel Prieto-Benítez)

ScienceDaily, May 23, 2011

Researchers from the King Juan Carlos University (URJC) have carried out a research study published in Biological Conservation, which looked at whether spiders were more tolerant of human impact than other animals. The answer was no: arachnids suffer the consequences of changes to their landscape just like any other animal.

"The abundance and number of spider species is negatively affected by the impact of many human land uses, such as habitat fragmentation, fire and pesticides," Samuel Prieto-Benítez and Marcos Méndez, researchers at the URJC Biodiversity and Conservation Department, said.

Given the "scarcity" of threatened spiders on the Red Lists, which are very in vogue at the moment, the researchers tried to find out whether spiders are exempt from the risks caused by human action, by means of a meta-study of a total of 173 scientific papers published since 1980, which provide more generalizable data.

"The technique used meant we could rigorously combine the results of a lot of studies. This is regularly used in medicine in order to arrive at general conclusions about the effects of drugs, based on numerous trials with more limited coverage," say Prieto-Benítez and Méndez, who studied the human impact in three ecosystems: farmland, pasture and woodland.

Until now, fewer than 20% of studies had indicated any negative effects of human impact on arachnids. The study, which has been published in Biological Conservation, demonstrates "evident" damaging effects on spider numbers due to the use of soil in farming and pasture systems. "In woodlands this was not so clear," the study explains.

Growing threats

In farming and pasture ecosystems all over world, fires, sheep-grazing and conventional crops have a harmful effect on arachnid fauna because they cause extreme changes to the vegetation structure. Spider abundance is affected in woodland by habitat fragmentation.

Insecticides also have a negative effect on spider diversity in agricultural and pasture ecosystems. The researchers show in the study that organic farming is more beneficial to arachnid abundance than conventional agriculture, but that these effects depend on the complexity of the landscape.

The study proposes some solutions for spider conservation. A reduction in mechanical alterations to the land, such as harvesting, ploughing and grazing would increase spider diversity in agricultural and pastural ecosystems. In addition, the use of insecticides should be more controlled, as in organic farming, and habitat fragmentation should be avoided.

According to the authors, although "they do not enjoy an excessive level of public sympathy," spiders are an important animal group for humans, since they free us of a large number of pest insects and are "very important" predators in the functioning of natural systems.

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by FECYT - Spanish Foundation for Science and Technology, viaEurekAlert!, a service of AAAS.

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Journal Reference:

1. Samuel Prieto-Benítez, Marcos Méndez. Effects of land management on the abundance and richness of spiders (Araneae): A meta-analysis. Biological Conservation, 2011; 144 (2): 683 DOI: 10.1016/j.biocon.2010.11.024

369. Climate Played Big Role in Vikings' Disappearance from Greenland

ScienceDaily, May 31, 2011

Greenland's early Viking settlers were subjected to rapidly changing climate. Temperatures plunged several degrees in a span of decades, according to research from Brown University. A reconstruction of 5,600 years of climate history from lakes near the Norse settlement in western Greenland also shows how climate affected the Dorset and Saqqaq cultures. Results appear in Proceedings of the National Academy of Sciences.

The end of the Norse settlements on Greenland likely will remain shrouded in mystery. While there is scant written evidence of the colony's demise in the 14th and early 15th centuries, archaeological remains can fill some of the blanks, but not all.

What climate scientists have been able to ascertain is that an extended cold snap, called the Little Ice Age, gripped Greenland beginning in the 1400s. This has been cited as a major cause of the Norse's disappearance. Now researchers led by Brown University show the climate turned colder in an earlier span of several decades, setting in motion the end of the Greenland Norse. Their findings appear in Proceedings of the National Academy of Sciences.

The Brown scientists' finding comes from the first reconstruction of 5,600 years of climate history from two lakes in Kangerlussuaq, near the Norse "Western Settlement." Unlike ice cores taken from the Greenland ice sheet hundreds of miles inland, the new lake core measurements reflect air temperatures where the Vikings lived, as well as those experienced by the Saqqaq and the Dorset, Stone Age cultures that preceded them.

"This is the first quantitative temperature record from the area they were living in," said William D'Andrea, the paper's first author, who earned his doctorate in geological sciences at Brown and is now a postdoctoral researcher at the University of Massachusetts-Amherst. "So we can say there is a definite cooling trend in the region right before the Norse disappear."

"The record shows how quickly temperature changed in the region and by how much," said co-author Yongsong Huang, professor of geological sciences at Brown, principal investigator of the NSF-funded project, and D'Andrea's Ph.D. adviser. "It is interesting to consider how rapid climate change may have impacted past societies, particularly in light of the rapid changes taking place today."

D'Andrea points out that climate is not the only factor in the demise of the Norse Western Settlement. The Vikings' sedentary lifestyle, reliance on agriculture and livestock for food, dependence on trade with Scandinavia and combative relations with the neighboring Inuit, are believed to be contributing factors.

Still, it appears that climate played a significant role. The Vikings arrived in Greenland in the 980s, establishing a string of small communities along Greenland's west coast. (Another grouping of communities, called the "Eastern Settlement" also was located on the west coast but farther south on the island.) The arrival coincided with a time of relatively mild weather, similar to that in Greenland today. However, beginning around 1100, the climate began an 80-year period in which temperatures dropped 4 degrees Celsius (7 degrees Fahrenheit), the Brown scientists concluded from the lake readings. While that may not be considered precipitous, especially in the summer, the change could have ushered in a number of hazards, including shorter crop-growing seasons, less available food for livestock and more sea ice that may have blocked trade.

"You have an interval when the summers are long and balmy and you build up the size of your farm, and then suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can't make as much hay. You can imagine how that particular lifestyle may not be able to make it," D'Andrea said.

Archaeological and written records show the Western Settlement persisted until sometime around the mid-1300s. The Eastern Settlement is believed to have vanished in the first two decades of the 1400s.

The researchers also examined how climate affected the Saqqaq and Dorset peoples. The Saqqaq arrived in Greenland around 2500 B.C. While there were warm and cold swings in temperature for centuries after their arrival, the climate took a turn for the bitter beginning roughly 850 B.C., the scientists found. "There is a major climate shift at this time," D'Andrea said. "It seems that it's not as much the speed of the cooling as the amplitude of the cooling. It gets much colder."

The Saqqaq exit coincides with the arrival of the Dorset people, who were more accustomed to hunting from the sea ice that would have accumulated with the colder climate at the time. Yet by around 50 B.C., the Dorset culture was waning in western Greenland, despite its affinity for cold weather. "It is possible that it got so cold they left, but there has to be more to it than that," D'Andrea said.

Contributing authors include Sherilyn Fritz from the University of Nebraska-Lincoln and N. John Anderson from Loughborough University in the United Kingdom. The National Science Foundation funded the work.

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Brown University.

368. One Billion Live in Hunger Due to Poverty, UN Says

A majority of the world's hungry are women and children

By Kanya D'Almeida, IPS, June 3, 2011

WASHINGTON, Jun 3, 2011 (IPS) - Today one billion people are living in hunger, not because of scarcity of production or a shortage of food on shelves in the global marketplace, but because they "lack the most basic purchasing power needed to acquire it", Olivier De Schutter, the United Nations Special Rapporteur on the Right to Food, said Thursday.

Currently, 35-40 percent of harvests are lost due to inadequate transportation and storage facilities, while a further 35-40 percent goes to wealthy Organization for Economic Cooperation and Development (OECD) countries.

According to experts like De Schutter, the inability of 10 percent of the world's population to feed itself is also a reflection of unsustainable patterns of consumption and deeply flawed models of industrialised agricultural production which, if allowed to continue, will divert 50 percent of global cereal harvests towards feeding cattle by the year 2050.

"From the food crisis in 1974, to the crisis in 2007-2008, and even now during the food crisis of 2010-2011, governments have had the same Pavlovian reaction - to increase production in order to lower prices and alleviate the burden of food price inflation on the population," De Schutter said at a panel discussion in Washington.

He added that while the reaction was understandable, it has been undeniably proven to be incomplete, short-sighted and based on an inadequate diagnosis of the complexity of the problem.

"A food system that is increasingly industrialised and commodified is not the only one available to us," he stressed. "We can and must re- imagine other food systems that take numerous social dimensions into account."

Inter-connected crises

In his recent report "Agroecology and the Right to Food", which was presented to the Human Rights Council in March this year, De Schutter outlines the global hunger catastrophe as an amalgamation of three distinct but inherently inter-related problems.

These are poverty, caused by trade policies that dump heavily- subsidised produce from developed countries on third world markets, thus rendering local farmers jobless; environmental degradation brought on by industrialised farming, which now accounts for nearly one-third of global green house gas emissions; and an epidemic of malnutrition caused by the colonising effects of mono-crops and a flood of processed food from the global north to the global south.

Only by examining these three challenges together can a strategy for ending hunger be successfully designed and implemented, he argues.

A study released Friday by the Consultative Group on International Agricultural Research (CGIAR)'s programme on Climate Change, Agriculture and Food Security (CCAFS) bolstered this argument by identifying future climate change "hotspots" in countries already crippled by severe food shortages and chronic hunger.

By consolidating detailed maps of scores of different agricultural regions across the world, the seven scientists behind the study tracked the impacts of climate change on food security and identified highly-vulnerable populations - principally in Africa and South Asia, with dark clouds hanging over China and parts of Latin America as well - that would suffer the double blows of hunger and environmental crisis.

"When you put these maps together they reveal places around the world where the arrival of stressful growing conditions could be especially disastrous," Polly Ericksen, lead author of the study and a senior scientist at the CGIAR's International Livestock Research Institute (ILRI) in Nairobi, Kenya, told the press in Copenhagen Friday.

"These are areas highly exposed to climate shifts, where survival is strongly linked to the fate of regional crop and livestock yields, and where chronic food problems indicate that farmers are already struggling and they lack the capacity to adapt to new weather patterns,” she said.

Swathes of South Asia, including virtually all of India's territory and vast areas of sub-Saharan Africa are home to 369 million food- insecure people, all of whom live in climate-vulnerable, agriculture- intensive areas.

Over 56 million hungry and crop-dependent people in West Africa, India and China inhabit areas which, in less than 40 years, will likely experience daily growing season temperatures of 30 degrees Celsius - virtually impossible conditions for essential crops like corn and rice.

Reimagining food systems

In 2006, a team of researchers from the University of Essex carried out a study on "agro-ecological" approaches to farming and development.

Spanning 57 developing countries and 286 different models of sustainable farming techniques in an area covering 37 million hectares - three percent of cultivated land - the study unearthed how low external-input farming that utilized surrounding ecosystems and cyclical practices resulted in a 79 percent yield increase, more than double the average yield under the normalised agricultural system.

Agro-ecology, which includes systems that produce their own fertiliser using materials and waste from the surrounding environment, is being increasingly viewed as the only viable solution to the hunger crisis. Since prices of fertiliser doubled during the 2008 food crisis, continents like Africa that import 95 percent of their chemical fertilisers could see radically different outcomes in production by adopting agro-ecological techniques.

Analysing the data from the 2006 study by region, the International Fund for Agricultural Development (IFAD) found that in some parts of Africa the yield increase was a stunning 213 percent.

However, De Schutter warned, this agricultural "revolution" will not come about by chance but will require swift and determined government action.

In addition to investing in education, gender-sensitive solutions and public goods and services such as the infrastructure required to nurture farmers' unions and peasant cooperatives, De Schutter's recommendations to governments include an urgent appeal to revolutionize markets to reward best-practices rather than short-term profit.

"The market as it exists today is too focused on global supply chains and does not give enough importance to local farmers, and producers of diversified crops," De Schutter told IPS.

"Governments must move away from export-led supply models and reinvest heavily in regional, sustainable food systems."

He added that governments should set solid agendas, which development agencies and private sector actors would align with, that incorporate a cultural shift away from a broken structure and towards a visionary, resilient food future. 

367. Questions of Race in Cuba

Esteban Morales

By Center for International Policy, Sacramento Bee, June 2, 2011

Washington--Today, the Center for International Policy hosted an all-day conference that explored the notion and implications of racism and racial identity in Cuba as the Afro-Cuban population struggles with widespread discrimination.  When Castro seized power in 1959, he declared Cuba a "raceless" society under the Communist project; however, socioeconomic disparities on racial lines remain clear.  Once considered taboo, discussions on race are becoming more prevalent in Cuba with the creation of National Union of Writers and Artists of Cuba (UNEAC) "Cuban Color" working groups and other race-related government organizations committed to dismantling barriers.

"The United States and Cuba share a common challenge.  Both have black minority populations and thus residual traces of racism; both must focus on how to eliminate these inconsistencies," said Wayne Smith, director of the Cuba project at the Center for International Policy.

To Smith, the conference's primary goal was "to understand how the Cubans are approaching the problem, with some commentary on its approach from the American perspective."  The participants discussed the implications of race on the Cuban nation, Afro-Cuban initiatives striving for racial equality, and the effect on these issues on U.S.-Cuban relations.

Conference panelists included Wayne Smith; James Early, Smithsonian Center of Folklife and Cultural Heritage; Esteban Morales, Center for the Study of U.S.-Cuban Relations; Heriberto Feraudy, Cuban Commission against Racism; Luis Murillo, Phelps Stokes; Julia Sweig, Council on Foreign Relations; and Philip Brenner, American University.  Emira Woods of the Institute of Policy Studies, Mwiza Munthali of TransAfrica Forum, and Sarah Stephens of the Center for Democracy in the Americas moderated the panels.

Esteban Morales underscored the importance of race in today's political discourse: "The topic of race is intimately connected with others, such as the economy, human rights, inequality, and social justice.  Avoiding the topic for so long has been a serious risk for the solid unity of the Cuban nation because national unity must be achieved by the construction of consensus among civil society."

By addressing these issues at the conference, James Early believes that the conference ultimately "supports the positive efforts of the Cuban people and the government to advance the interrelated goals of social equality, political and cultural democracy, and economic development."

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By Juan O. Tamayo, Miami Herald, June 3, 2011

Washington, D.C. The Cuban government will soon cast a media spotlight on the issue of racism on the island, although some programs to improve the lives of black Cubans had to be cut because of economic restraints, a Havana official said Thursday.

Heriberto Feraudy, who heads the quasi-official Cuban Commission against Racism, also said the popularity of Afro-Cuban religions is soaring and indicated that Raúl Castro’s economic reforms may not help blacks as much as whites.

Feraudy, who served 15 years as ambassador to five African nations, and Esteban Morales, a well-known Havana economist who writes often on race, addressed a conference on the issue sponsored by the Center for International Policy, a think tank.

Their unusually frank comments — for decades Cuba officially denied the existence of discrimination on the island — seemed to reflect the growing concern over race issues as the country drops some of its socialist policies and embraces more private enterprise.

Feraudy and Morales — both black — argued that the Fidel and Raúl Castro governments have done more for Cuban blacks since 1952 than any other government in the previous centuries.

“The problem of a division in Cuba (due to racial issues) is not possible,” said Morales, who was reportedly suspended from the Communist Party last year after he wrote a column complaining about the island’s burgeoning official corruption.

But both also agreed that racism persists on the island, and that the issue needs to be discussed and confronted even though “many people” in Cuba argue that the Castro revolution did away with racial discrimination.

Feraudy said some programs adopted under Fidel Castro to help blacks “had to be terminated” because of a shortage of resources — he gave no further details — but added that his commission is pushing for a broad discussion of the race issue.

Cuban state television will soon launch a one-year run of programs on Africa and its importance to the island, he said, and the parliamentary National Assembly of People’s Power has agreed to take up the issue in one of its coming sessions.

Morales joked that some Cubans, “even at some levels of power,” argue that all race problems in Cuba disappeared after 1959 because the revolutionary government outlawed discrimination “and we are very good people.”

Now racism is a “democratic issue that we must discuss in Cuba” with all of civil society, he added. But the discussion must be handled carefully to avoid simply raising concerns without providing answers.

Feraudy noted that Raúl Castro has called for an increase of blacks in top positions and that the Central Committee of the ruling Communist Party selected last month showed a 10 percent increased in the number of black and mestizo members.

But he indicated that he agreed with widespread concerns that Castro’s proposals to boost the economy by allowing more private enterprise and slashing government payrolls subsidies would hit blacks harder than whites.

Whites receive more remittances from abroad, which could be used to start one the newly legalized businesses, because most exiles are white, he noted.

Feraudy’s committee was created two years ago by the government-controlled Cuban Union of Writers and Artists (UNEAC) as black dissidents began using the language of black U.S. activists to attack the Castro governments.

366. Ancient Male Humanoid Stayed Home While Females Roamed, Study Finds

"Mrs. Ples" is the most famous example
of Australopithecus africanus from Sterkfontein
cave, South Africa.

By Nicholas Wade, The New York Times, June 1, 2011

Researchers studying the diet of human ancestors who lived two million years ago in southern Africa have unexpectedly come across a crucial clue to their social structure. The males never strayed far from home, and the females dispersed after puberty to neighboring groups.

The pattern of female dispersal is not unexpected, since it is practiced by chimpanzees, the closest living species to humans, and by some hunter-gatherers. But social behavior does not fossilize, and any data on the subject is invaluable in reconstructing how human social structure evolved.

“This is the first direct evidence that we have about the residence pattern of hominins,” said Bernard Chapais, a primatologist and expert on human social evolution at the University of Montreal.

The evidence emerged from study of the fossil teeth of 19 australopithecines, the still apelike ancestors of the human lineage. The makeup of teeth can reflect local geography because some chemicals like strontium are drawn from rocks into plants, and then into tooth enamel when the plants are eaten. In australopithecines, the absorption of strontium continued until the teeth were completed around age 8.

The researchers were measuring different versions, or isotopes, of strontium to see if the australopithecines traveled far from home in search of food. As the data rolled out of the measuring device, “we were at first disappointed,” said Julia Lee-Thorp of Oxford University, a member of the research team, “but we soon realized that we had found another prize.”

This was that half the females had been born far away, whereas all the males had grown up locally, the team reported Wednesday in the journal Nature. The team was led by Sandi R. Copeland of the Max Planck Institute for Evolutionary Anthropology in Germany.

In most mammals, the females stay in the home community and the males disperse after adolescence to avoid inbreeding. But chimpanzees and many human hunter-gatherer groups are unusual in following the opposite pattern. The reason may have to do with the aggressive territoriality of both species: A group of males who have grown up with one another is more cohesive and better at defending a territory against competitors. This obliges the females to be the gender that disperses.

“It’s really nice to see there is biological continuity from chimpanzees to australopithecines,” said Joan B. Silk, an expert on primate social behavior at the University of California, Los Angeles.

The joint ancestor of chimps and humans lived about five million years ago and is often assumed to have had a chimplike social structure, with a male hierarchy, promiscuous mating by the females and all-out war between neighboring bands. The central puzzle of human social evolution, in Dr. Chapais’s view, is to explain how promiscuity was replaced by the pair bond and aggressive relations were pushed up from the band level to that of the tribe, a group of bands tied together by the exchange of women.

The australopithecines studied by Dr. Copeland’s team still had a somewhat chimplike social structure, Dr. Chapais said, because the pair bond did not evolve until the appearance of Homo erectus around 1.8 million years ago. The australopithecine fossils came from the Sterkfontein valley, and one of them has been dated to 2.2 million years ago.

The pair bond, in his view, arose when human ancestors started to develop more dispersed sources of food and males increasingly guarded a group of females to protect both them and their own paternity. With the male around anyway, he could also help rear the children, which allowed for a longer period of juvenile dependence and hence for brain size to grow. The relatively small size of the australopithecine brain suggests that this process had not yet started, Dr. Chapais said.

Another far-reaching consequence of the developing pair bond was that individuals could at last start to recognize their relatives, which chimpanzees mostly cannot do. So when females dispersed to neighboring groups, males from their home community could recognize their daughters or sisters, together with their in-laws, who had an equal interest in their children’s welfare. This transformed the neighboring group from an adversary to an ally, and the human social structure expanded to being that of a tribe. Friendly relations, in Dr. Chapais’s view, then allowed males as well as females to transfer, the pattern typical of hunter-gatherers today.

“It is great to think that we might be in a position to begin dating such major events in our evolution,” he said of the new finding.

The australopithecine fossils are few and precious, and researchers are reluctant to damage them in any way. In a new technique, a barely visible pit is blasted out of a tooth with a laser and the vaporized enamel is passed into a mass spectrometer, which measures the amount of strontium or any other element of interest. The researchers started out looking at carbon isotopes, which showed them that australopithecines had a highly variable diet. To determine whether that was because they ranged far and wide, the researchers then looked at strontium isotopes, the ratio of which varies according to the local geology. And this led to the discovery of the female dispersal pattern.