Tuesday, January 31, 2012

Are religious people better adjusted psychologically?

Psychological research has found that religious people feel great about themselves, with a tendency toward higher social self-esteem and better psychological adjustment than non-believers. But a new study published in Psychological Science, a journal of the Association for Psychological Science, finds that this is only true in countries that put a high value on religion.

The researchers got their data from eDarling, a European dating site that is affiliated with eHarmony. Like eHarmony, eDarling uses a long questionnaire to match clients with potential dates. It includes a question about how important your personal religious beliefs are and questions that get at social self-esteem and how psychologically well-adjusted people are. Jochen Gebauer of the Humboldt-Universität zu Berlin, Constantine Sedikides of the University of Southampton, and Wiebke Neberich of Affinitas GmbH in Berlin, the company behind eDarling, used 187,957 people's answers to do their analyses.

As in other studies, the researchers found that more religious people had higher social self-esteem and where psychologically better adjusted. But they suspected that the reason for this was that religious people are better in living up to their societal values in religious societies, which in turn should lead to higher social self-esteem and better psychological adjustment. The people in the study lived in 11 different European countries, ranging from Sweden, the least religious country on the planet, to devoutly Catholic Poland. They used people's answers to figure out how religious the different countries were and then compared the countries.

On average, believers only got the psychological benefits of being religious if they lived in a country that values religiosity. In countries where most people aren't religious, religious people didn't have higher self-esteem. "We think you only pat yourself on the back for being religious if you live in a social system that values religiosity," Gebauer says. So a very religious person might have high social self esteem in religious Poland, but not in non-religious Sweden.

In this study, the researchers made comparisons between different countries, but another study found a similar effect within one country, between students at religious and non-religious universities. "The same might be true when you compare different states in the U.S. or different cities," Gebauer says. "Probably you could mimic the same result in Germany, if you compare Bavaria where many people are religious and Berlin where very few people are religious."

EurekAlert. 2012. "Are religious people better adjusted psychologically?". EurekAlert. Posted: January 19, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/afps-arp011912.php

Monday, January 30, 2012

Museums and national identities

How museums are used and can be used to create a sense of community and identity is the theme for an event as part of the EuNaMus project. The event takes place in Brussels on 25 January.

Creating new national museums is a growing trend, both globally and within Europe. The challenge is to create unity and a common understanding of the history in evolving multi-ethnic and multicultural countries. However the challenge is not new, says Peter Aronsson, professor in Cultural Heritage and the Uses of History at Linköping University and coordinator of the European research project EuNaMus on Europe's national museums.

EuNaMus is a three-year project funded by the EU's Seventh Framework Programme. Eight European universities are involved and the project is coordinated from Sweden.

"The issue of assembling many different ethnic groups within one nation is not a new concept, just think about the great multicultural states Germany's and Italy's unification during the 1800s. National museums have long been used to create a binding element, a sense that "we belong together" in a national community, this despite their differences."

Aronsson claims that the current challenge for multicultural Europe can be addressed in two ways: either that diversity is affirmed, rendered harmless and culturally useful, or that it is seen as a threat that must be encountered by stronger integration.

Parallel to the issue of a national community is the one what Europeans actually have in common. Several other initiatives are also underway to create European museums.

These initiatives and trends will be discussed at an outreach event of the EuNaMus project in Brussels on 25 January. This will be followed by a more scientific conference on 26 and 27 January that will address how a conflict-ridden history is to be handled at national museums. One example that will be brought to the fore is Europe's dark colonial history.

EurekAlert. 2012. "Museums and national identities". EurekAlert. Posted: January 18, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/lu-man011812.php

Sunday, January 29, 2012

Gossip can have social and psychological benefits

UC Berkeley researchers find rumor-mongering has some positive outcomes

For centuries, gossip has been dismissed as salacious, idle chatter that can damage reputations and erode trust. But a new study from the University of California, Berkeley, suggests rumor-mongering can have positive outcomes such as helping us police bad behavior, prevent exploitation and lower stress.

"Gossip gets a bad rap, but we're finding evidence that it plays a critical role in the maintenance of social order," said UC Berkeley social psychologist Robb Willer, a coauthor of the study published in this month's online issue of the Journal of Personality and Social Psychology.

The study also found that gossip can be therapeutic. Volunteers' heart rates increased when they witnessed someone behaving badly, but this increase was tempered when they were able to pass on the information to alert others.

"Spreading information about the person whom they had seen behave badly tended to make people feel better, quieting the frustration that drove their gossip," Willer said.

So strong is the urge to warn others about unsavory characters that participants in the UC Berkeley study sacrificed money to send a "gossip note" to warn those about to play against cheaters in economic trust games. Overall, the findings indicate that people need not feel bad about revealing the vices of others, especially if it helps save someone from exploitation, the researchers said.

"We shouldn't feel guilty for gossiping if the gossip helps prevent others from being taken advantage of," said Matthew Feinberg, a UC Berkeley social psychologist and lead author of the paper.

The study focused on "prosocial" gossip that "has the function of warning others about untrustworthy or dishonest people," said Willer, as opposed to the voyeuristic rumor-mongering about the ups and downs of such tabloid celebrities as Kim Kardashian and Charlie Sheen.

In a series of four experiments, researchers used games in which the players' generosity toward each other was measured by how many dollars or points they shared. In the first experiment, 51 volunteers were hooked up to heart rate monitors as they observed the scores of two people playing the game. After a couple of rounds, the observers could see that one player was not playing by the rules and was hoarding all the points.

Observers' heart rates increased as they witnessed the cheating, and most seized the opportunity to slip a "gossip note" to warn a new player that his or her contender was unlikely to play fair. The experience of passing on the information calmed this rise in heart rate.

"Passing on the gossip note ameliorated their negative feelings and tempered their frustration," Willer said. "Gossiping made them feel better."

In the second experiment, 111 participants filled out questionnaires about their level of altruism and cooperativeness. They then observed monitors showing the scores from three rounds of the economic trust game, and saw that one player was cheating.

The more prosocial observers reported feeling frustrated by the betrayal and then relieved to be given a chance to pass a gossip note to the next player to prevent exploitation.

"A central reason for engaging in gossip was to help others out – more so than just to talk trash about the selfish individual," Feinberg said. "Also, the higher participants scored on being altruistic, the more likely they were to experience negative emotions after witnessing the selfish behavior and the more likely they were to engage in the gossip."

To raise the stakes, participants in the third experiment were asked to go so far as to sacrifice the pay they received to be in the study if they wanted to send a gossip note. Moreover, their sacrifice would not negatively impact the selfish player's score. Still, a large majority of observers agreed to take the financial hit just to send the gossip note.

"People paid money to gossip even when they couldn't affect the selfish person's outcome," Feinberg said.

In the final study, 300 participants from around the country were recruited via Craigslist to play several rounds of the economic trust game online. They played using raffle tickets that would be entered in a drawing for a $50 cash prize –-an extra incentive to hold on to as many raffle tickets as possible.

Some players were told that the observers during a break could pass a gossip note to players in the next round to alert them to individuals not playing fairly. The threat of being the subject of negative gossip spurred virtually all the players to act more generously, especially those who had scored low on an altruism questionnaire taken prior to the game.

Together, the results from all four experiments show that "when we observe someone behave in an immoral way, we get frustrated," Willer said. "But being able to communicate this information to others who could be helped makes us feel better."


EurekAlert. "Gossip can have social and psychological benefits". EurekAlert. Posted: January 17, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/uoc--gch011712.php

Saturday, January 28, 2012

Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World

As he cleared trees on his family’s land decades ago near Rio Branco, an outpost in the far western reaches of the Brazilian Amazon, a series of deep earthen avenues carved into the soil came into focus.

“These lines were too perfect not to have been made by man,” said Mr. Araújo, a 62-year-old cattleman. “The only explanation I had was that they must have been trenches for the war against the Bolivians.”

But these were no foxholes, at least not for any conflict waged here at the dawn of the 20th century. According to stunning archaeological discoveries here in recent years, the earthworks on Mr. Araújo’s land and hundreds like them nearby are much, much older — potentially upending the conventional understanding of the world’s largest tropical rain forest.

The deforestation that has stripped the Amazon since the 1970s has also exposed a long-hidden secret lurking underneath thick rain forest: flawlessly designed geometric shapes spanning hundreds of yards in diameter.

Alceu Ranzi, a Brazilian scholar who helped discover the squares, octagons, circles, rectangles and ovals that make up the land carvings, said these geoglyphs found on deforested land were as significant as the famous Nazca lines, the enigmatic animal symbols visible from the air in southern Peru.

“What impressed me the most about these geoglyphs was their geometric precision, and how they emerged from forest we had all been taught was untouched except by a few nomadic tribes,” said Mr. Ranzi, a paleontologist who first saw the geoglyphs in the 1970s and, years later, surveyed them by plane.

For some scholars of human history in Amazonia, the geoglyphs in the Brazilian state of Acre and other archaeological sites suggest that the forests of the western Amazon, previously considered uninhabitable for sophisticated societies partly because of the quality of their soils, may not have been as “Edenic” as some environmentalists contend.

Instead of being pristine forests, barely inhabited by people, parts of the Amazon may have been home for centuries to large populations numbering well into the thousands and living in dozens of towns connected by road networks, explains the American writer Charles C. Mann. In fact, according to Mr. Mann, the British explorer Percy Fawcett vanished on his 1925 quest to find the lost “City of Z” in the Xingu, one area with such urban settlements.

In addition to parts of the Amazon being “much more thickly populated than previously thought,” Mr. Mann, the author of “1491,” a groundbreaking book about the Americas before the arrival of Columbus, said, “these people purposefully modified their environment in long-lasting ways.”

As a result of long stretches of such human habitation, South America’s colossal forests may have been a lot smaller at times, with big areas resembling relatively empty savannas.

Such revelations do not fit comfortably into today’s politically charged debate over razing parts of the forests, with some environmentalists opposed to allowing any large-scale agriculture, like cattle ranching and soybean cultivation, to advance further into Amazonia.

Scientists here say they, too, oppose wholesale burning of the forests, even if research suggests that the Amazon supported intensive agriculture in the past. Indeed, they say other swaths of the tropics, notably in Africa, could potentially benefit from strategies once used in the Amazon to overcome soil constraints.

“If one wants to recreate pre-Columbian Amazonia, most of the forest needs to be removed, with many people and a managed, highly productive landscape replacing it,” said William Woods, a geographer at the University of Kansas who is part of a team studying the Acre geoglyphs.

“I know that this will not sit well with ardent environmentalists,” Mr. Woods said, “but what else can one say?”

While researchers piece together the Amazon’s ecological history, mystery still shrouds the origins of the geoglyphs and the people who made them. So far, 290 such earthworks have been found in Acre, along with about 70 others in Bolivia and 30 in the Brazilian states of Amazonas and Rondônia.

Researchers first viewed the geoglyphs in the 1970s, after Brazil’s military dictatorship encouraged settlers to move to Acre and other parts of the Amazon, using the nationalist slogan “occupy to avoid surrendering” to justify the settlement that resulted in deforestation.

But little scientific attention was paid to the discovery until Mr. Ranzi, the Brazilian scientist, began his surveys in the late 1990s, and Brazilian, Finnish and American researchers began finding more geoglyphs by using high-resolution satellite imagery and small planes to fly over the Amazon.

Denise Schaan, an archaeologist at the Federal University of Pará in Brazil who now leads research on the geoglyphs, said radiocarbon testing indicated that they were built 1,000 to 2,000 years ago, and might have been rebuilt several times during that period.

Initially, Ms. Schaan said, researchers, pondering the 20-foot depth of some of the trenches, thought they were used to defend against attacks. But a lack of signs of human settlement within and around the earthworks, like vestiges of housing and trash piles, as well as soil modification for farming, discounted that theory.

Researchers now believe that the geoglyphs may have held ceremonial importance, similar, perhaps, to the medieval cathedrals in Europe. This spiritual role, said William Balée, an anthropologist at Tulane University, could have been one that involved “geometry and gigantism.”

Still, the geoglyphs, located at a crossroads between Andean and Amazonian cultures, remain an enigma.

They are far from pre-Columbian settlements discovered elsewhere in the Amazon. Big gaps also remain in what is known about indigenous people in this part of the Amazon, after thousands were enslaved, killed or forced from their lands during the rubber boom that began in the late 19th century.

For Brazil’s scientists and researchers, Ms. Schaan said, the earthworks are “one of the most important discoveries of our time.” But the repopulation of this part of the Amazon threatens the survival of the geoglyphs, after being hidden for centuries.

Forests still cover most of Acre, but in cleared areas where the geoglyphs are found, dirt roads already cut through some of the earthworks. People live in wooden shacks inside others. Electricity poles dot the geoglyphs. Some ranchers use their trenches as watering holes for cattle.

“It’s a disgrace that our patrimony is treated this way,” said Tiago Juruá, the author of a new book here about protecting archaeological sites including the earthworks.

Mr. Juruá, a biologist, and other researchers say the geoglyphs found so far are probably just a sampling of what Acre’s forests still guard under their canopies. After all, they contend that outside of modern cities, fewer people live today in the Amazon than did before the arrival of Europeans five centuries ago.

“This is a new frontier for exploration and science,” Mr. Juruá said. “The challenge now is to make more discoveries in forests that are still standing, with the hope that they won’t soon be destroyed.”

Romero, Simon. 2012. "Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World". New York Times. Posted: January 14, 2012. Available online: http://www.nytimes.com/2012/01/15/world/americas/land-carvings-attest-to-amazons-lost-world.html

Friday, January 27, 2012

Outer-Hebrides survey builds a new picture of the past

A recent call to local people to report anything unusual that they have spotted at the shoreline or under the sea has already resulted in several promising sites for a new archaeological project.

Tip-offs from islanders led to a possible medieval fishing village and finds of 5,000-year-old pottery submerged in a loch.

A local man – JJ McDonald – told the team that he knew of a “medieval fishing station”. Photographed from above, the landscape shows high potential for new site discovery of all periods of history. Notably, this area near North Loch Euport is called ‘Havn’ (the Norse word for harbour) on Ordnance Survey maps. A previously unknown complex of fish traps and evidence of coastal occupation south of Lochboisdale on South Uist was discovered during flight surveys.

At Loch Duna – a freshwater loch – a local diver has discovered ceramics which date to the early Neolithic period. He reported his discovery of the 5000-year-old pottery to the local museum just days after attending the first public lecture on underwater archaeology given by the Outer Hebrides Coastal Community Marine Archaeology Pilot Project (OHCCMAPP) team in July.

The call went out in 2011 to fishermen, beachcombers, divers and residents in the Western Isles.

The project searches for previously unidentified prehistoric and historic remains in the coastal and marine areas of the Isles, all the way from Berneray to the Butt of Lewis and all islands in between.

Many of these places are only accessible for short periods each day due to the tides – or are now fully submerged because of rising sea levels – and have not always been looked at in detail by archaeologists. As a result, it is hoped that this project could lead to a number of significant new discoveries.

Speaking on behalf of the project, Dr Jonathan Benjamin of WA Coastal & Marine said:
“As full time archaeologists, we don’t have the benefit of observing the shoreline between the low and high tides, day in and day out, year after year. That’s why we’re relying on the knowledge of people who live and work on or near the sea, and who might have noticed something out of the ordinary, either in a fishing net, or at an especially low tide. Their tip-offs can lead to significant discoveries. We’re also explaining to people the sorts of things that we’re interested in, because they may have seen or noticed things in the past, but disregarded them as not important.

“Until now, there’s been no major study focused on the marine archaeology of the Outer Hebrides, and by beginning with the intertidal and shallow waters, aerial survey and community engagement, we hope to be able to demonstrate that there is a vast amount of knowledge, literally waiting to be discovered by archaeologists working with local residents on land, in the air and underwater.”

Now members of the project team have had a chance to fly over some of the remote sites they’ve been told about, with a Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) aerial survey team.

Aerial photographs have been taken with the advantage of low winter sunshine which tends to highlight archaeological features in the landscape.

Already they have identified several sites as warranting further investigation – possibly even full ground and underwater archaeological surveys – in the future.

The project – a partnership between RCAHMS, WA Coastal & Marine, Historic Scotland and Comhairle nan Eilean Siar (CNE-Siar) – aims to get local people involved in sharing their knowledge about features in the landscape in order to build up a picture of how people lived and worked on the islands over the last 9,000 years.

Remains found on the coastline, or even now fully underwater, can then be recorded, cared for and preserved. With rising sea-levels and the power of the tides, many of these sites are at risk of being lost.

Speaking about one of the most promising tip-offs received to date, Dr Alex Hale, archaeological investigator at RCAHMS, said:
“Meeting JJ MacDonald was one of those fortuitous moments that can only happen when you are in the field. We bumped into JJ at his boat shed, by chance, and the amount of knowledge he has of the local environment is incredible. He’s obviously very knowledgeable about the area of South Uist where he lives and was able to help us identify sites that we’ll now be able to investigate further, such as the fishing station.”

Past Horizons. 2012. "Outer-Hebrides survey builds a new picture of the past". Past Horizons. Posted: Available online: http://www.pasthorizonspr.com/index.php/archives/01/2012/outer-hebrides-survey-builds-a-new-picture-of-the-past

Thursday, January 26, 2012

Deaf sign language users pick up faster on body language

Deaf people who use sign language are quicker at recognizing and interpreting body language than hearing non-signers, according to new research from investigators at UC Davis and UC Irvine.

The work suggests that deaf people may be especially adept at picking up on subtle visual traits in the actions of others, an ability that could be useful for some sensitive jobs, such as airport screening.

"There are a lot of anecdotes about deaf people being better able to pick up on body language, but this is the first evidence of that," said David Corina, professor in the UC Davis Department of Linguistics and Center for Mind and Brain.

Corina and graduate student Michael Grosvald, now a postdoctoral researcher at UC Irvine, measured the response times of both deaf and hearing people to a series of video clips showing people making American Sign Language signs or "non-language" gestures, such as stroking the chin. Their work was published online Dec. 6 in the journal Cognition.

"We expected that deaf people would recognize sign language faster than hearing people, as the deaf people know and use sign language daily, but the real surprise was that deaf people also were about 100 milliseconds faster at recognizing non-language gestures than were hearing people," Corina said.

This work is important because it suggests that the human ability for communication is modifiable and is not limited to speech, Corina said. Deaf people show us that language can be expressed by the hands and be perceived through the visual system. When this happens, deaf signers get the added benefit of being able to recognize non-language actions better than hearing people who do not know a sign language, Corina said.

The study supports the idea that sign language is based on a modification of the system that all humans use to recognize gestures and body language, rather than working through a completely different system, Corina said.

EurekAlert. 2012. "Deaf sign language users pick up faster on body language". EurekAlert. Posted: January 12, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/uoc--dsl011212.php

Wednesday, January 25, 2012

We may be less happy, but our language isn't

"If it bleeds, it leads," goes the cynical saying with television and newspaper editors. In other words, most news is bad news and the worst news gets the big story on the front page.

So one might expect the New York Times to contain, on average, more negative and unhappy types of words — like "war," " funeral," "cancer," "murder" — than positive, happy ones — like "love," "peace" and "hero."

Or take Twitter. A popular image of what people tweet about may contain a lot of complaints about bad days, worse coffee, busted relationships and lousy sitcoms. Again, it might be reasonable to guess that a giant bag containing all the words from the world's tweets — on average — would be more negative and unhappy than positive and happy.

But new research shows just the opposite.

"English, it turns out, is strongly biased toward being positive," said Peter Dodds, an applied mathematician at the University of Vermont.

The UVM team's study "Positivity of the English Language," is presented in the Jan. 11 issue of the journal PLoS ONE.

This new study complements another study the same Vermont scientists presented in the Dec. 7 issue of PLoS ONE, "Temporal Patterns of Happiness and Information in a Global Social Network."

That work attracted wide media attention showing that average global happiness, based on Twitter data, has been dropping for the past two years.

Combined, the two studies show that short-term average happiness has dropped — against the backdrop of the long-term fundamental positivity of the English language.

In the new study, Dodds and his colleagues gathered billions of words from four sources: twenty years of the New York Times, the Google Books Project (with millions of titles going back to 1520), Twitter and a half-century of music lyrics.

"The big surprise is that in each of these four sources it's the same," says Dodds. "We looked at the top 5,000 words in each, in terms of frequency, and in all of those words you see a preponderance of happier words."

Or, as they write in their study, "a positivity bias is universal," both for very common words and less common ones and across sources as diverse as tweets, lyrics and British literature.

Why is this? "It's not to say that everything is fine and happy," Dodds says. "It's just that language is social."

In contrast to traditional economic theory, which suggests people are inherently and rationally selfish, a wave of new social science and neuroscience data shows something quite different: that we are a pro-social storytelling species. As language emerged and evolved over the last million years, positive words, it seems, have been more widely and deeply engrained into our communications than negative ones.

"If you want to remain in a social contract with other people, you can't be a…," well, Dodds here used a word that is rather too negative to be fit to print — which makes the point.

This new work adds depth to the Twitter study that the Vermont scientists published in December that attracted attention from NPR, Time magazine and other media outlets.

"After that mild downer story, we can say, 'But wait — there's still happiness in the bank," Dodds notes. "On average, there's always a net happiness to language."

Both studies drew on a service from Amazon called Mechanical Turk. On this website, the UVM researchers paid a group of volunteers to rate, from one to nine, their sense of the "happiness" — the emotional temperature — of the 10,222 most common words gathered from the four sources. Averaging their scores, the volunteers rated, for example, "laughter" at 8.50, "food" 7.44, "truck" 5.48, "greed" 3.06 and "terrorist" 1.30.

The Vermont team — including Dodds, Isabel Kloumann, Chris Danforth, Kameron Harris, and Catherine Bliss — then took these scores and applied them to the huge pools of words they collected. Unlike some other studies — with smaller samples or that elicited strong emotional words from volunteers — the new UVM study, based solely on frequency of use, found that "positive words strongly outnumber negative words overall."

This seems to lend support to the so-called Pollyanna Principle, put forth in 1969, that argues for a universal human tendency to use positive words more often, easily and in more ways than negative words.

Of course, most people would rank some words, like "the," with the same score: a neutral 5. Other words, like "pregnancy," have a wide spread, with some people ranking it high and others low. At the top of this list of words that elicited strongly divergent feelings: "profanities, alcohol and tobacco, religion, both capitalism and socialism, sex, marriage, fast foods, climate, and cultural phenomena such as the Beatles, the iPhone, and zombies," the researchers write.

"A lot of these words — the neutral words or ones that have big standard deviations — get washed out when we use them as a measure," Dodds notes. Instead, the trends he and his team have observed are driven by the bulk of English words tending to be happy.

If we think of words as atoms and sentences as molecules that combine to form a whole text, "we're looking at atoms," says Dodds. "A lot of news is bad," he says, and short-term happiness may rise and and fall like the cycles of the economy, "but the atoms of the story — of language — are, overall, on the positive side."

EurekAlert. 2012. "We may be less happy, but our language isn't". EurekAlert. Posted: January 12, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/uov-wmb011212.php

Tuesday, January 24, 2012

Siberia was a wildlife refuge in the last ice age

SIBERIA, a name that conjures up images of snow and ice, may have been an unlikely refuge from the bitter cold of the last ice age. Ancient DNA from the region paints a picture of remarkably stable animal and plant life in the teeth of plunging temperatures. The findings could help predict how ecosystems will adapt to future climate change.

The permanently frozen soil of Siberia, Canada and Alaska preserves the DNA of prehistoric plants, fungi and animals. "It's a giant molecular freezer," says James Haile at Murdoch University in Perth, Western Australia.

Glacial ice can also contain ancient DNA but permafrost is much more abundant than ice and so should provide a more complete picture of the effects of prehistoric climate change, says Haile. Last month, at the International Barcode of Life Conference in Adelaide, South Australia, his colleague Eva Bellemain of the University of Oslo in Norway revealed the first fruits of their analysis of Siberian permafrost DNA.

The samples were extracted from 15,000 to 25,000-year-old frozen sediment in southern Chukotka in north-eastern Siberia. Their age is significant: around 20,000 years ago temperatures plummeted and ice sheets blanketed much of the northern hemisphere - but parts of Siberia, Canada and Alaska apparently stayed ice-free (Quaternary Science Reviews, DOI: 10.1016/j.quascirev.2011.07.020).

Fossils and pollen found in these regions suggest they may have acted as a refuge for plants and animals during this time, but Bellemain turned to fungal DNA to get a complete picture of the environment. Many fungi consume plants, and so indicate the plant life around at the time.

Using 23 permafrost cores, Bellemain identified around 40 fungal taxa that thrived during the last ice age. "We didn't expect to find so much," she says.

The diversity of fungi found suggests that a brimming plant community thrived in northern Siberia to support them. This range of plants should also have sustained a diverse assembly of mammals - and the samples indeed contain DNA from woolly rhinoceros (Coelodonta antiquitatis), woolly mammoths (Mammuthus primigenius), reindeer (Rangifer tarandus) and moose (Alces alces) dating back to between 15,000 and 25,000 years ago (Molecular Ecology, DOI: 10.1111/j.1365-294x.2011.05306.x).

Meanwhile, Haile and Tina Jørgensen at the University of Copenhagen in Denmark have used ancient DNA together with pollen and fossil evidence to reconstruct the plant life surrounding Lake Taymyr, on the Taymyr peninsula in northern Siberia. Using 18 cores from five sites around the lake, the team identified 66 plant taxa that stuck around from 46,000 to 12,000 years ago, even though temperatures in the region fluctuated by some 20 °C during this period. "I was surprised that the [living] environment remained stable for so long," says Jørgensen (Molecular Ecology, DOI: 10.1111/j.1365-294x.2011.05287.x).

The result does not surprise Gregory Retallack at the University of Oregon in Eugene, who studies plant remains in ancient soils that have been fossilised. "A part of this stability is down to the inertia of ecosystems," he says.

Haile and colleagues are now keen to analyse other samples to uncover how the prehistoric flora and fauna in Canada and Alaska were affected by climate change.

Andrew Lowe at the University of Adelaide thinks the results could be used in climate models "to tell us how future communities will change". But Retallack thinks such predictions will not be possible until we know, for example, how the flora and fauna were affected by large pulses of warming 70,000 and 125,000 years ago.

Zukerman, Wendy. 2012. "Siberia was a wildlife refuge in the last ice age ". New Scientist. Posted: January 10, 2012. Available online: http://www.newscientist.com/article/mg21328464.900-siberia-was-a-wildlife-refuge-in-the-last-ice-age.html

Monday, January 23, 2012

Using Modern Tools to Reconstruct Ancient Life

To the naked eye, the white, powdery substance appeared to be plaster. That’s what the professional and volunteer archaeologists at a dig in Israel concluded.

To be certain, though, they subjected the chalky dust to spectroscopy and a petrographic microscope, only to discover that it was not a manufactured substance, but decayed plant life and fecal matter.

What that meant to the archaeologists from the Leon Levy Expedition to Ashkelon — a former seaport south of Tel Aviv that was home to successive civilizations over thousands of years — was that structures thought to have been inhabited by people were more likely occupied by animals. That revelation upended their view of what they were excavating.

“For archaeologists,” said the expedition’s co-director, Daniel M. Master, a professor at Wheaton College in Illinois, “it was the difference between a palace and a stable.”

This marriage of social and natural sciences is an emerging discipline that has been called microarchaeology by Steve Weiner, director of the Kimmel Center for Archaeological Science in the Weizmann Institute in Israel, which is collaborating with the expedition.

“The unique approach at Weizmann is not about instruments nor about methodologies,” Dr. Weiner said. “It is all about solving archaeological problems with the help of instrumentation — both in the field and in the lab.”

Weizmann archaeology researchers have a laboratory on the site here, along with equipment to study archaeometallurgy, ancient DNA, radiocarbon dating and micromorphology, the microscopic structures found in organisms and soil. A $2 million accelerator mass spectrometer is on order.

“We have developed a whole new integrative approach to archaeology that starts with the team identifying a good problem in the field and then continues interactively between field and lab,” Dr. Weiner said.

Dr. Master said: “Steve’s team demonstrated that the white lamina that archaeologists have routinely called ‘bits of plaster’ were actually degraded plant remains. Further, his team showed ways of analyzing these plants that could detect the difference between sheaves of grain and plant bits mixed into animal dung.”

Dr. Master and Lawrence E. Stager, director of the Semitic Museum at Harvard University, who has overseen the dig for 25 years, embarked on a mutually beneficial collaboration with the Kimmel Center after Dr. Master was invited to lecture there. Suddenly, new windows opened.

Sifting sediment through flotation turned up lint near mysterious clay cylinders. That discovery, Dr. Master recalled, demonstrated that the clay cylinders were actually loom weights, and “this observation has led to a revolution in the studies of the weaving industry across the eastern Mediterranean in the early Iron Age.”

Soil chemistry analysis found that a four-horned altar thought to be a traditional Levantine device for burning incense was not used for burning at all. Archaeologists identified it instead as a Mycenaean and Minoan libation altar on which liquids were poured.

“Our work with the Weizmann team has been a leap forward,” Dr. Master said.

Sharing workers and a mobile laboratory allows the expedition to analyze samples rapidly and adjust its excavating techniques accordingly. The application of pure science to practical challenges enables Kimmel Center experts to hone their research skills. The collaboration is not unique, but it is unusual for a discipline that falls between the humanities and natural science.

“In Israel, archaeology is taught in the faculties of the humanities, making it very difficult for archaeologists to fully exploit the powerful new scientific tools,” Dr. Weiner said.

“Although there is much good will both on the side of natural scientists intrigued by the exciting archaeological questions to be addressed and the archaeologists who are eager to obtain the information provided by scientific tools, a chasm of miscommunication exists between the two camps,” he said. “The frequent result is that minimal benefit is obtained from maximal effort.”

The collaboration with the Leon Levy Expedition, he said, means “we excavate, analyze samples in minutes, get results, change excavation strategy, sample as well as we can and then continue in the base camp lab and, between seasons, in the home lab.”

Last summer, Michael Toffolo, a 27-year-old doctoral student at Tel Aviv University who conducts his lab work as a visiting student at the Kimmel Center, was lent to the Leon Levy Expedition, which was unearthing an ash layer dating from 604 B.C., when the Babylonians led by Nebuchadnezzar sacked the walled seaport.

“Among all the pieces of information that I managed to gather so far with my lab work, the most important is probably the presence of phytolith floors” composed of microscopic plant remains, he said.

Mr. Toffolo was able to determine whether the floors were made of wild grasses used as bedding, or agricultural byproducts like straw, or ash from wood used as fuel. As a result, what originally looked like plaster turned out to be cereal husks on which an iron plow point was lying; a grain storage pit from the Egyptian period; and a floor composed of woven palm leaves.

“This type of information can change the archaeological interpretation of an entire structure or building, according to the human activities identified,” Mr. Toffolo said.

The discovery that the white powder was not plaster led scientists to the conclusion that a rural economy existed in an Iron Age town center.

“Floors also define a stratigraphic layer — everything below is older and above younger,” Dr. Weiner said.

Each June and July, the six-week Leon Levy Expedition to Ashkelon draws college students and other volunteers. Sponsored since 1985 by the Leon Levy Foundation, the expedition is administered by the Harvard Semitic Museum and a consortium that includes Wheaton and Boston Colleges and is conducted under the auspices of the Israel Antiquities Authority.

Dr. Weiner said, “We try to solve archaeological problems using the macroscopic record — what you see — and the microscopic record — revealed by instruments.” Weizmann is working with several other Israeli excavations.

“We do not always have success answering our questions in archaeology, and sometimes microarchaeology is frustrating,” Dr. Master said, “but together we are using all the tools at our disposal to uncover the clues that will help us to reconstruct ancient life at Ashkelon.”


Roberts, Sam. 2012. "Using Modern Tools to Reconstruct Ancient Life". New York Times. Posted: January 9, 2012. Available online: http://www.nytimes.com/2012/01/10/science/archaeologists-use-modern-tools-to-reconstruct-ancient-life.html

Sunday, January 22, 2012

Forty new rock art sites recorded in Mexico

Rock-art has been discovered and recorded in forty sites in northeastern Guanajuato, Mexico, as part of an ongoing project carried out by researchers from the National Institute of Anthropology and History (INAH).

The majority of the images were created by hunter-gatherers who occupied the area during the 1-5 centuries AD, but religious iconography and inscriptions were also discovered dating to the colonial era, as well as the 19th and early 20th centuries

The findings were announced by lead archaeologist Carlos Viramontes after four seasons of research in the area of Queretaro and Guanajuato semi-desert.

“We have found more than three thousand pictorial motifs in 40 locations, distributed in the municipalities of Tierra Blanca, San Luis de la Paz, San Diego Union, Xichú and Victoria, in Guanajuato.

Altogether, since the late eighties over 70 rock-art sites have been recorded, with those falling into the two thousand year old hunter-gatherer category being preliminarily classified into two groups:

* public – involving large numbers of people creating iconography as part of a ritual in easy to access sites located near the foothills and in the valleys.
* private – where it is believed that a small select group attended ceremonies in hard to access ravines and canyons.

Public and private ritual spaces

The sites known as Manitas, in the community of Tierra Blanca and Cerro Redondo represent good examples of the two classifications explains Viramontes. Tierra Blanca feels like a private ritual space, located near a 3,400 m high mountain peak in a difficult to access ravine. Depicted here are human figures, plants and animals – some of them fantastical creatures – as well as some geometric lines along with red and black painted hands.

On the other hand, Cerro Redondo appears to be a place where public rituals have taken place, involving large numbers of people. It is located on an easily accessible hillock in the middle of a plain.

Characteristic paint colours favoured by the hunter gatherers were yellow, red and black and used to paint human figures adorned with headdresses, skirts and cloaks, sometimes depicted carrying as yet unidentified objects and sometimes carrying bows and arrows in scenes of hunting and war.

“There is a great diversity of animals represented – mainly deer, but also dogs and insects resembling centipedes and spiders and many birds ” explained Viramontes.

The archaeologist theorises that for these hunter gatherers, the act of creating images on rock surfaces went beyond just recording daily life events and rituals; he contends that the rock face itself was a point of contact between the material and the spiritual worlds.

Religious iconography

Apart from the two thousand year old rock-art recorded during the project, other types discovered relate to the colonial era and comprise crosses, shrines, altars and dated inscriptions. These were drawn with white pigmentation, typical of the Otomi people who settled in Guanajuato and Queretaro semi-desert, from the sixteenth century.

Past Horizons. 2012. "Forty new rock art sites recorded in Mexico". Past Horizons. Posted: January 8, 2012. Available online: http://www.pasthorizonspr.com/index.php/archives/01/2012/forty-new-rock-art-sites-recorded-in-mexico

Saturday, January 21, 2012

Learn language faster with gestures

LANGUAGE classes of the future might come with a physical workout. People learn a new language more easily when words are accompanied by movement.

Manuela Macedonia and Thomas Knösche at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, enrolled 20 volunteers on a six-day course to learn "Vimmi", an artificial language designed to make study results easier to interpret. Half of the material was taught using spoken and written instructions and exercises, while the other half was taught with body movements to accompany each word, which the students were asked to act out.

Students remembered significantly more of the words taught with movement, and used them more readily when creating new sentences (Mind, Brain and Education, DOI: 10.1111/j.1751-228X.2011.01129.x).

Whilst this may seem intuitive for words that have a physical counterpart, like "cut", the pair were surprised to find the trick also worked for abstract words like "rather" that have no obvious gestural equivalent.

Based on fMRI scans, the pair argue that enactment helps memory by creating a more complex representation of the word that makes it more easily retrieved. Unpublished results from tests in real language classes suggest that the method "could really speed up foreign language learning in schools", says Macedonia.

2012. "Learn language faster with gestures". New Scientist. Posted: January 3, 2012. Available online: http://www.newscientist.com/article/mg21228442.800-learn-language-faster-with-gestures.html

Friday, January 20, 2012

Scientists crack medieval bone code

Two teams of Michigan State University researchers – one working at a medieval burial site in Albania, the other at a DNA lab in East Lansing – have shown how modern science can unlock the mysteries of the past.

The scientists are the first to confirm the existence of brucellosis, an infectious disease still prevalent today, in ancient skeletal remains.

The findings, which appear in the American Journal of Physical Anthropology, suggest brucellosis has been endemic to Albania since at least the Middle Ages.

Although rare in the United States, brucellosis remains a major problem in the Mediterranean region and other parts of the world. Characterized by chronic respiratory illness and fever, brucellosis is acquired by eating infected meat or unpasteurized dairy products or by coming into contact with animals carrying the brucella bacteria.

Todd Fenton, associate professor of anthropology, said advanced DNA testing at MSU allowed the researchers to confirm the existence of the disease in skeletons that were about 1,000 years old.

"For years, we had to hypothesize the cause of pathological conditions like this," Fenton said. "So the era of DNA testing and the contributions that DNA can make to my work are really exciting."

Here's how the discovery came about.

Fenton and a group of MSU graduate students were serving as the bioarcheologists, or bone specialists, for a multinational team of archaeologists excavating sites in the ancient Albanian city of Butrint. Once a large Roman colony, Butrint in its final centuries served as an outpost of the Byzantine Empire until it was abandoned in the Middle Ages due to flooding.

Fenton and his team developed biological profiles of the human remains, which included determining sex, age and skeletal pathologies, or health histories. Vertebrae from two of the Byzantine-era skeletons – both adolescent males from the 10th century to the 13th century – had significant lesions, leading the researchers to theorize the boys had suffered from tuberculosis.

Samples of the ancient bone were sent to the forensic DNA lab in East Lansing, which is headed by David Foran, director of MSU's Forensic Science Program. Foran and his team of graduate students took tiny portions of the bone, extracted DNA and tested it for any residual DNA that might still exist from the expected pathogen.

But the results came back negative for tuberculosis.

Fenton's team re-examined the bones that tested negative for tuberculosis and concluded the disease might instead be brucellosis. The infection from brucellosis and tuberculosis causes similar damage – basically eating away the bone – although no one had ever confirmed brucellosis in human bone recovered from an archaeological site.

Foran's team then developed a different set of tests for detecting the brucella bacteria and undertook a new round of testing on the diseased vertebrae.

This time the results came back positive for brucellosis.

Foran said the collaboration on the project highlights the benefits of modern science and interdisciplinary research, even when the respective research teams are some 5,000 miles apart.

"In this case it was a combination of inquisitiveness, persistence and of course collaboration," Foran said. "It is amazing to find something brand new in something that is a thousand years old."

EurekAlert. 2012. "Scientists crack medieval bone code ". EurekAlert. Posted: January 3, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-01/msu-scm010312.php

Thursday, January 19, 2012

Khmer, Like Mayans, Fell Under the Weather

On different sides of the planet, two civilizations shared many similarities, including a vulnerability to regional climate changes.

The classical period Mayans in Central America and the Khmer in Southeast Asia both hacked a space for their people out of tropical forests and constructed impressive stone cities with sophisticated water storage systems. But their Achilles heel was a dependence on seasonal rains for their crops and drinking water. When regional climate changes caused erratic rainfall, their cities and fields may have dried out and left them vulnerable to collapse.

Between the 9th and 15th centuries, the Khmer Empire dominated much of what is now Laos, Cambodia, Thailand, Vietnam and Burma (Myanmar). The empire's famous capital, Angkor, may have been one of the largest pre-industrial city complexes in the world. The empire was supported by an extensive water management system, including lake-sized reservoirs called barays.

But reservoirs only work if there is rainwater to fill them. Research recently published in the Proceedings of the National Academy of Sciences suggests that a series of erratic monsoons may have destabilized the once-mighty Khmer.

Researchers led by Mary Beth Day, an earth scientist with the University of Cambridge, found evidence of a series of failed monsoons in 14th and 15th century that coincided with the Khmer's collapse. Sediments in the largest Khmer resevoir, the West Baray, showed that extremely heavy downpours were followed by drought. The heavy rains may have washed away crops, and those that survived shriveled in the drought. During the dry spells, drinking water may have run low as well.

Although many other factors came into play, such as the threat of Mongol invasion and social upheaval brought on by the spread of Theravada Buddhism, the researchers note that an inability to feed their people could have weakened the Khmer to the point of collapse.

The Mayans of the classical period (c. 250 – 900 AD) could have warned the Khmer. While the Khmer were rising, the classical Mayans were falling, possible because the rains weren't.

The Mayans too seem to have been dependent on seasonal rains. They often built their cities near natural reservoirs called cenotes or near rivers, then augmented nature with their own water management systems, such as the dam at Kinal and reservoirs at Uxul. Mayans even had pressurized water.

But when the rains failed, so did some of the Mayan city states, suggest some researchers including Jared Diamond in the book Collapse.

Hacking a home out of the forest may have had an effect on rainfall, as well. Forests help to create rainfall when they respire moisture and help keep the ground moist. When large amounts of forest were cleared for agriculture, it may have reduced rainfall. When the rains do come, they wash away the soil which is no longer protected by the trees.

The causes of a civilizations' failure are complex, and the verdict is still out on what ultimately toppled the Mayans and Khmer. But evidence suggests decades long changes in rainfall patterns may have had a serious effect.


Wall, Tim. 2012. "Khmer, Like Mayans, Fell Under the Weather". . Posted: January 5, 2012. Available online: http://news.discovery.com/earth/khmer-collapsed-under-climate-pressure-120105.html

Wednesday, January 18, 2012

Model unlocks human impact on Africa's fire regimes

A model has helped shed light on how human-started fires shaped Africa's landscape, researchers report.

Before human activity became widespread, most fires were caused by lightning strikes during the continent's wet seasons, they said.

As the human population expanded, more fires occurred during the dry season, triggering a shift in the impact of fires on Africa's ecology, they added.

The findings appear in the Proceedings of the National Academy of Sciences.

"People have always been aware that there have been a lot of wildfires in Africa," said co-author Sally Archibald, senior researcher at the Council for Scientific and Industrial Research, South Africa.

"When we started getting satellite data, it became even more apparent that there is a lot of burning that happens.

"This made people concerned; they were worried that there was too much fire in Africa."

Human impact

Dr Archibald explained that the team decided to develop the model in order to understand current conditions, and whether there was now too much burning compared with the time when humans were not so prevalent and influencing landscapes' "fire regimes".

It has been estimated that early humans could have had the ability to start fires about 300,000 years ago, but the real impact was from about 70,000 years ago as human populations became more widespread.

"We really cannot make good (conservation) decisions unless we can understand how humans have manipulated fire," added Dr Archibald.

"It is really interesting that we are the only organism in the world to have harnessed fire, and we need to understand how that may have changed the systems in which we live."

The theoretical model, which focuses on Africa's grassland habitats, took data on how people have used fire and linked it to archaeological knowledge of how human populations in the region evolved.

Dr Archibald told BBC News that one of the paper's key insights was that, according to the model, wildfires were currently at their "lowest level for the past 40,000 years or so".

"There is less wildfire in Africa now, even though it looks like there is such a lot when you look at the satellite data, because of the way that people have been using the landscape."

She explained that the model could be used to help national parks develop fire management policies.

"They are trying to develop fire management policies and they want to burn their landscapes in a way that will maintain biodiversity," she said.

"That becomes quite a tricky question in Africa because you cannot just say 'well, I will not light fires at all, only natural fires will be allowed'.

"People have been in Africa for over a million years, so you cannot try to suppress all human fires. You have to include humans as part of your system, and fire managers still need some guidance on what is the best way to burn these systems and yet maintain biodiversity."

Kinver, Mark. 2012. "Model unlocks human impact on Africa's fire regimes". BBC News. Posted: December 30, 2011. Available online: http://www.bbc.co.uk/news/science-environment-16247844

Tuesday, January 17, 2012

Prehistoric bones a cottage industry in Siberia

One of Zimov's prized mammoth tusks.
Source: Dmitry Solovyov/NBC News

It’s hard to imagine, looking out at the frozen expanses of Yakutia, in North Eastern Siberia, that 30,000 or so years ago, so many animal species, now extinct, roamed the Pleistocene grasslands. From 12-foot tall, five-ton wooly mammoth bulls to tiny rodents, an Ice Age hunter would have found as many as 100 animals in each square mile he tracked, at least according to Sergei Zimov, our Ice Age expert, geo-physicist and guide during our recent visit.

Today, Siberia’s thick icy crust, or permafrost, which has held the remains of predators and herbivores alike in an epochal deep freeze, is beginning to melt. And the bones of prehistoric rhinos, bison, reindeer, horses – and yes, mammoths – are rising to Yakutia’s surface at an amazing rate. One literally trips over bones on a short stroll along the banks of the Kolyma River. The downside, of course, is the attendant release of so much CO2 – a greenhouse gas - as this melting permafrost exposes a 150-foot thick layer of plant and animal remains. But there is an upside: a burgeoning cottage industry in the finding and selling of prehistoric bones.

Zimov says that 30 years ago, only a handful of Russian "bone" men – serious businessmen - were attracted to the adventurous lifestyle, spending their summers combing Pleistocene beaches and valleys. Today, at least 1,000 bone hunters work throughout Russia, with several dozen focusing on Siberia’s permafrost zone, where the best prizes are to be found.

Professional hunters like Feodor Shidlovsky and Alexander Votagin are at the top of the bone chain. Shidlovsky has arguably the biggest mammoth bone collection in Russia, displaying them in his own natural history museum in Moscow. The money he makes from the sale of mammoth bones goes into his exhibitions, the funding of artists who fashion jewelry from the ancient bone, and scientific expeditions.

Every summer, Votagin leads his team to Dvarii Yar – or Windy Cliffs – a remote stretch of Kolyma riverbank that has given up the richest finds of prehistoric bones over the past decade. Located about 400 miles north of Zimov’s isolated science station in Cherskiy - Yakutia’s main airport and hub - the so-called New Siberian Islands (all underwater in Pleistocene times) are now a treasure trove of bones. Local hunters collect more than 20 tons of mammoth, rhino and bison bones a year, selling most of them to local dealers in Cherskiy – presumably to sell them to tourists like us, though the Russian government bans the export abroad.

And here’s why: prehistoric bones can be a very lucrative catch. While fishermen and hunters now augment their meager incomes with up to $10 per mammoth tooth or ivory shard, the more professional - and lucky – hunters can fetch more than $80,000 for a pair of mammoth tusks in good condition. Zimov keeps such a pair in the living room of his science station cum abode – but isn’t tempted to sell them.

"These are like my family," he told us. "Would you sell your brothers for $80,000?" In fact, Zimov has never sold any bones he’s collected over his decades of combing Yakutia for clues to global warming. On one such outing, he and his son Nikita collected some 1,200 bones – which he thinks is a world record - all which remained of a pack of mammoths and all within a few hundred yards of beach. For amusement, they arranged their bone hoard into the shapes of mammoths, horses and bison.

Until the mass, mysterious extinction of so many Ice Age animals took place - triggered, probably, by extreme change of climate and habitat - the so-called "Mammoth Steppe Eco-system" chugged along like a glacier, both efficient and self-sustaining. Mammoths knocked over heat-absorbing trees, grasses grew, and dozens of herbivore species not only grazed on those grasses, but fertilized them too.

Though that eco-system died some 15,000 years ago, mammoths and other Pleistocene throwbacks are helping to maintain today’s human population, with a $5 prehistoric bison jaw here, a $10 wooly rhino knee bone there or $1,000 piece of wooly mammoth tusk, buried right under your feet.

Maceda, Jim. 2012. "Prehistoric bones a cottage industry in Siberia". MSNBC: The Daily Nightly. Posted: Available online: http://dailynightly.msnbc.msn.com/_news/2011/12/30/9834873-prehistoric-bones-a-cottage-industry-in-siberia

Monday, January 16, 2012

Top 10 Hominid Discoveries of 2011

10. Earliest Modern Humans in Europe: Paleoanthropologists believe modern humans (Homo sapiens) came to Europe about 43,000 years ago. This date is based on the age of sophisticated stone tools, not human fossils. This year two teams dated European fossils that are in line with the age of the tools: A human upper jaw discovered in southern England in 1927 was dated to 44,000 years ago, and two molars unearthed in Italy were dated to 45,000 years ago. These fossils are the oldest known human remains on the continent.

9. The Arches of Australopithecus afarensis: There’s no doubt that Lucy and her species, Australopithecus afarensis, walked upright. But the degree to which these hominids walked on the ground has been debated. The discovery of a 3.2-million-year-old foot bone confirmed that Lucy and her kind had arched feet and therefore probably walked much like modern people. The researchers who studied the fossil say it indicates Australopithecus afarensis no longer needed to spend much time in the treetops; however, other researchers disagree, saying hominids at this time were still good tree climbers.

8. World’s Earliest Mattress: In a rock shelter in South Africa, archaeologists uncovered a 77,000-year-old mattress composed of thin layers of sedges and grasses, predating all other known mattresses by 50,000 years. Early humans knew how to keep the bed bugs out; the bedding was stuffed with leaves from the Cape Laurel tree (Cryptocarya woodii), which release chemicals known to kill mosquitos and other bugs.

7. Neanderthal Mountaineers: Neanderthals evolved many traits to deal with the cold; for example, their short limbs helped them conserve heat. A mathematical analysis revealed that short limbs may have also helped Neanderthals walk more efficiently in mountainous terrains. Specifically, the fact that Neanderthals had shorter shins relative to their thighs meant they didn’t need to lift their legs as high while walking uphill, compared to modern people with longer legs. “For a given step length, they [needed] to put in less effort,” said lead research Ryan Higgins of Johns Hopkins University.

6. The First Art Studio: Archaeologists working in South Africa’s Blombos Cave discovered early humans had a knack for chemistry. In a 100,000-year-old workshop, they found all of the raw materials needed to make paint, as well as abalone shells used as storage containers—evidence that our ancestors were capable of long-term planning at this time.

5. Australopithecine Females Strayed, Males Stayed Close to Home: In many monkey species, when males reach adolescence, they leave their home to search for a new group, probably as a way to avoid breeding with their female relatives. In chimpanzees and some humans, the opposite occurs: Females move away. Now it appears that australopithecines followed the chimp/human pattern. Researchers studied the composition of strontium isotopes found in the teeth of members of Australopithecus africanus and Paranthropus robustus. An individual consumes strontium through food and it is taken up by the teeth during childhood. Because the isotopes (different forms of the element) in plants and animals vary by geology and location, strontium can be used as a proxy for an individual’s location before adulthood. In the study, the researchers discovered that large individuals, presumably males, tended to have strontium isotope ratios typical of the area where the fossils were found; smaller individuals, or females, had non-local strontium isotope ratios, indicating they had moved into the area as adults.

4. Confirmation of Pre-Clovis People in North America: Since the 1930s, archaeologists have thought the Clovis people, known for their fluted projectile points, were the first people to arrive in the New World, about 13,000 years ago. But in recent years there have been hints that someone else got to North America first. The discovery of more than 15,000 stone artifacts in central Texas, dating to between 13,200 and 15,500 years ago, confirmed those suspicions. Corroborating evidence came from Washington State, where a mastodon rib containing a projectile point was dated this year to 13,800 years ago.

3. Denisovans Left A Mark in Modern DNA: The Denisovans lived in Eurasia sometime between 30,000 and 50,000 years ago. Scientists don’t know what they looked like; the only evidence of this extinct hominid group is DNA extracted from a bone fragment retrieved from a cave in Siberia. But this year, several studies revealed the mysterious population bred with several lineages of modern humans; people native to Southeast Asia, Australia, Melanesia, Polynesia and elsewhere in Oceania carry Denisovan DNA.

2. Out of Africa and Into Arabia: Traditionally, paleoanthropologists have thought modern humans left Africa through the Sinai Peninsula and into the Levant. But some researchers suggest our ancestors took a more southerly route, across the Red Sea and into southern Arabia. This year, several studies provided evidence pointing to this exit strategy. First, a team reported the discovery of 125,000-year-old stone tools in the United Arab Emirates. The researchers suggested humans ventured into Arabia when sea level was lower, making a trip across the Red Sea easier. (Geologists later verified the climate would have been just right at this time.) No fossils were found with the tools, but the scientists concluded they belonged to modern humans rather than Neanderthals or some other contemporaneous hominid. Another study this year complemented the finding: Paleoanthropologists also found stone tools, dating to 106,000 years ago, in Oman. The researchers say the artifacts match tools of the Nubian Complex, which are found only in the Horn of Africa. This connection implies the makers of those African tools, most likely modern humans, made the migration into Oman.

1. Australopithecus sediba, Candidate for Homo Ancestor: Last year, scientists announced the discovery of a new hominid species from South Africa’s Cradle of Humankind—Australopithecus sediba. This year, the researchers announced the results of an in-depth analysis of the 1.97-million-year-old species. They say a mix of australopithecine and Homo-like traits make Australopithecus sediba, or a species very similar to it, a possible direct ancestor of our own genus, Homo.

Erin Wayman writes the blog "Hominid Hunting" at the Smithsonian website. Visit the blog here to read more fascinating Hominid stories.

Wayman, Erin. 2012. "Top 10 Hominid Discoveries of 2011". Smithsonian Magazine. Posted: December 28, 2011. Available online: http://blogs.smithsonianmag.com/hominids/2011/12/top-10-hominid-discoveries-of-2011/

Sunday, January 15, 2012

Ancient Texts Part of Earliest Known Documents

Image: Detail of the Tower of Babel stele, with the engraving of King Nebuchadnezzar II. (Copyright The Schøyen Collection, MS 2063).

A team of scholars has discovered what might be the oldest representation of the Tower of Babel of Biblical fame, they report in a newly published book.

Carved on a black stone, which has already been dubbed the Tower of Babel stele, the inscription dates to 604-562 BCE.

It was found in the collection of Martin Schøyen, a businessman from Norway who owns the largest private manuscript assemblage formed in the 20th century.

Consisting of 13,717 manuscript items spanning over‭ ‬5,000‭ ‬years, the collection includes parts of the Dead Sea Scrolls, ancient Buddhist manuscript rescued from the Taliban, and even cylcon symbols by Australia's Aborigines which can be up to 20,000 years old.

The collection also includes a large number of pictographic and cuneiform tablets -- which are some of the earliest known written documents -- seals and royal inscription spanning most of the written history of Mesopotamia, an area near modern Iraq.

A total of 107 cuneiform texts dating from the Uruk period about 5,000 years ago to the Persian period about 2,400 years ago, have been now translated by an international group of scholars and published in the book Cuneiform Royal Inscriptions and Related Texts in the Schøyen Collection.

The Tower of Babel stele stands out as one of "the stars in the firmament of the book," wrote Andrew George, a professor of Babylonian at the University of London and editor of the book.

The spectacular stone monument clearly shows the Tower and King Nebuchadnezzar II, who ruled Babylon some 2,500 years ago.

Credited with the destruction of the temple of Solomon in 586 BCE, Nebuchadnezzar II was also responsible for sending the Jews into exile, according to the Bible.

The first Babylonian king to rule Egypt, he is also famous for building the legendary Hanging Gardens, one of the 7 wonders of the ancient world, and many temples all over Babylonia.

Calling himself the "great restorer and builder of holy places," he also reconstructed Etemenanki, a 7-story, almost 300-foot-high temple (also known as a ziggurat) dedicated to the god Marduk.

Biblical scholars believe that this temple may be the Tower of Babel mentioned in the Bible.

In the inscription, the standing figure of Nebuchadnezzar II is portrayed with his royal conical hat, holding a staff in his left hand and a scroll with the rebuilding plans of the Tower (or a foundation nail) in his outstretched right hand.

According to George, the relief yields only the fourth certain representation of Nebuchadnezzar II.

"The others are carved on cliff-faces in Lebanon at Wadi Brisa (which has two reliefs) and at Shir es-Sanam. All these outdoor monuments are in very poor condition," he wrote.

The inscription also depicts the Tower of Babel from a front view, "clearly showing the relative proportions of the 7 steps including the temple on the top," the Schøyen Collection stated.

The stele even features a line drawing of the ground plan of the temple, revealing both the outer walls and the inner arrangement of rooms (click here for a drawing reconstruction).

Moreover, captions clearly identify the tower as the "great ziggurat of Babylon."

King Nebuchadnezzar himself talks about the amazing construction:

"I made it the wonder of the people of the world, I raised its top to the heaven, made doors for the gates, and I covered it with bitumen and bricks," the inscription reads in the translation by professor George.

Depicted in a long series of fanciful paintings, including artworks by Pieter Brueghel the Elder, Gustave Doré, and M. C. Escher, the Tower of Babel is mentioned in the Bible, which says the people of Babylon were trying to build a tower to heaven.

God concluded that they were simply trying to gain power and caused the workers to speak many different languages. Unable to communicate with each other, the workers gave up the project.

"Here we have for the first time an illustration contemporary with Nebuchadnezzar II's restoring and enlargement of the Tower of Babel, and with a caption making the identity absolutely sure," the Schøyen Collection stated on its website.

Lorenzi, Rossella. 2012. "Ancient Texts Part of Earliest Known Documents". Discovery News. Posted: December 27, 2011. Available online: http://news.discovery.com/history/tower-of-babel-111227.html

Saturday, January 14, 2012

Irikaitz archaeological site -- host to a 25,000-year-old pendant

In the open air, full of volcanic rocks, difficult to date ... the excavations here are unique, according to Alvaro Arrizabalaga and his team at the University of the Basque Country

The recent discovery of a pendant at the Irikaitz archaeological site in Zestoa (in the Basque province of Gipuzkoa) has given rise to intense debate: it may be as old as 25,000 years, which would make it the oldest found to date at open-air excavations throughout the whole of the Iberian Peninsula. This stone is nine centimetres long and has a hole for hanging it from the neck although it would seem that, apart from being adornment, it was used to sharpen tools. The discovery has had great repercussion, but it is not by any means the only one uncovered here by the team led by Álvaro Arrizabalaga: "Almost every year some archaeological artefact of great value is discovered; at times, even 8 or 10. It is a highly fruitful location".

Irikaitz lies behind the bath spa in Zestoa, on the other side of the river Urola, 14 metres from the river bank. The archaeologist from the University of the Basque Country (UPV/EHU) has been carrying out excavations here summer after summer, together with students and researchers from this and other universities and in cooperation with Aranzadi Science Society. Since 1998 they have uncovered 32 square metres; nothing compared to the eight hectares (at least) that this "gigantic" open-air site covers. This is archaeology, demanding a lot of patience, but the results are worth it: "You feel as if you have found something that has been waiting to fall into your hands for 200,000 years".

It is like a lottery

The tasks pertaining to an archaeological site are complex and lengthy in any case, but particularly so at Irikaiz. To start with, because it is in the open air. In the case of caves, it is known that they served as refuges for our ancestors and, once their location is identified, it is highly possible that archaeological treasures are found there. Open air archaeological sites, on the other hand, are discovered when some civil engineering infrastructure has to be built, and it is difficult to predict what will be found. Moreover, in Zestoa there are remains from the Lower Paleolithic, when there are hardly any references from this period in the Basque Country. According to Mr Arrizabalaga, when they started, "it was like a lottery. We did not know what to expect – either about its chronology or about the kinds of remains likely to be uncovered".

Precisely because of this lack of references, they were fascinated when they came across "totally exotic" raw material: volcanic stones. "In the first dig, we thought at first that someone may have brought the rocks there when they were building the Urola railway, to use them as ballast. It was all so surprising and incredible", said the archaeologist. But no; this phenomenon had another logical explanation: "It is a geological rarity. In the Urola River valley there is a layer of volcanic stones; the river cut through these, took them to the surface and brought them to this place. This is why humans from prehistory came here – there was no other place in the Basque Country with stones like these".

A margin of 350,000 years

The fact that the remains are so old or the features of the materials thereof so unusual make dating in Irikaitz very difficult, as most of the methods commonly used to this end are of little use here. A clear example of this is that any kind of dating with bone remains has had to be totally discarded; unlike in other sites; here there are hardly any such remains, the earth here being so acidic that it has consumed almost everything in this respect, leaving only stone tools and plant fossils.

There are, thus, few means for dating certain remains. There were two periods of human occupation in Irikaitz, the most recent being 25,000 years ago, the pendant discovered this summer being from that time. But, it is the older occupation that gives headaches in trying to date it. Yes, it dates from the early Stone Age (Lower Palaeolithic), but when exactly? There hardly exist archaeological sites similar to this one, to act as a reference. As this archaeologist explained, "there is no other case of the Lower Palaeolithic under these conditions along the strip of land bordered by the Bay of Biscay, and only a few like it in the whole of the Iberian Peninsula". It is impossible to narrow the dating to less than an interval of 350,000 years: "We know it cannot date from later than 150,000 years ago (when that period ended), and neither can it be prior to 500,000 years ago, because the sea covered the area during that period".

Therefore, of the 18-20 dating methods currently available, there are no more than two applicable to Irikaitz. Both involve luminescence, and with which Arrizabalaga's team are attempting to get results. The first method acts to specify when the sun illuminated a piece of quartz for the last time; without the wished-for results, however. The second is based on thermo-luminescence, a method with which they are working currently: this is applied to certain types of stones which have undergone heating from fires, and the measurement is based on the amount of radiation accumulated.

Since 1998, more than 500 people have carried out field work at this prehistoric archaeological site of Irikaitz; without counting those who have contributed from the laboratory. This has included a considerable group of researchers who have worked tenaciously in the search for any result, no matter how small. Many of these research workers belong to the UPV/EHU, like Mr Arrizabalaga. And, although the fruit of their work is harvested little by little, they feel they are rewarded. "If you Google Irikaitz, some 7,000 entries appear. We started digging in 1998 and, by 2001, the site was mentioned as a reference not written by us, in relation to the history of this geographical area".

EurekAlert. 2012. "Irikaitz archaeological site -- host to a 25,000-year-old pendant". EurekAlert. Posted: December 27, 2011. Available online: http://www.eurekalert.org/pub_releases/2011-12/ef-ias122711.php

Friday, January 13, 2012

Humans on many roads to Asia

The discovery by Russian archaeologists of the remains of an extinct prehistoric human during the excavation of Denisova Cave in Southern Siberia in 2008 was nothing short of a scientific sensation. The sequencing of the nuclear genome taken from a circa. 30,000-year-old finger bone revealed that Denisova man was neither a Neanderthal nor modern human, but a new form of hominin. Minute traces of the Denisova genome are still found in some individuals living today. The comparisons of the DNA of modern humans and prehistoric human species provide new indications of how human populations settled in Asia over 44,000 years ago.

Tracking Denisovan DNA

As scientists from Harvard Medical School in Boston (USA) and the Max Planck Institute for Evolutionary Anthropology in Leipzig have discovered, the Denisova hominin passed on genetic material not only to populations that live in New Guinea today, but also to Australian aborigines and population groups in the Philippines. David Reich, professor of Genetics at Harvard Medical School, says: “The Denisovan DNA is comparable to a medical contrast agent that can be used to make a person’s blood vessels visible. It has such a high recognition value that even small volumes can be detected in individuals. Therefore, we were able to track down Denisovan DNA in human dispersals. The sequencing of prehistoric DNA is an important tool for researching human evolution.”

The scientists have discovered that, contrary to the information available up to now, modern humans possibly populated Asia in at least two migration waves. According to David Reich, the original inhabitants who still populate Southeast Asia and Oceania today came from the first migration wave. Later migrations formed populations in East Asia that are related to the population found in Southeast Asia today.

Accordingly, Denisova hominins were spread across an extraordinarily large ecological and geographical area extending from Siberia to tropical Southeast Asia. “The fact that Denisovan DNA can be detected in some but not other original inhabitant populations living in Southeast Asia today shows that numerous populations with and without Denisovan DNA existed over 44,000 years ago,” says Mark Stoneking, professor at the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology and leading author of the study. “The simplest explanation for the presence of Denisovan genetic material in some but not all groups is that Denisova people themselves lived in Southeast Asia.”

In December 2010, Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology reported in the journal Nature that Denisova hominins contributed genes to human populations living in New Guinea today.

Genetic footprint

The new study, which was initiated by Mark Stoneking – an expert in the field of human genetic variation in Southeast Asia and Oceania – is now researching the genetic footprint that the Denisova hominin has left behind in us modern humans. The scientists analysed the genomes of 33 populations living in Southeast Asia and Oceania today, including people from Borneo, Fiji, Indonesia, Malaysia, Australia, the Philippines, Papua New Guinea and Polynesia. Some of this data were already available and others were recorded in the context of the current study.

The analysis carried out by the researchers shows that the Denisova hominin contributed genetic material not only to the people living in New Guinea today but also to Australian aborigines, the Mamanwa, a Philippine “Negrito” group, and some other populations in eastern Southeast Asia and Oceania. In contrast, western and northwestern groups, including other “Negrito” groups, such as the Onge people who inhabit the Andaman Islands and the Jehai of Malaysia, and the mainland East Asians did not mix with the Denisova people.

The researchers conclude from this that Denisova hominins interbred with modern humans at least 44,000 years ago, before the Australians and inhabitants of New Guinea separated from each other. As opposed to this, Southeast Asia was first colonised by modern humans who were not related to today’s Chinese and Indonesian populations. The latter arrived in the course of subsequent migratory movements. This hypothesis on the settlement of Southeast Asia and Oceania, which is referred to as the “South Route” has already been substantiated by archaeological finds. However, strong support in the form of genetic evidence has yet to be found.

Past Horizons. 2012. "Humans on many roads to Asia". Past Horizons. Posted: December 22, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/12/2011/humans-on-many-roads-to-asia

Thursday, January 12, 2012

Deciphered Ancient Tablet Reveals Curse of Greengrocer

A fiery ancient curse inscribed on two sides of a thin lead tablet was meant to afflict, not a king or pharaoh, but a simple greengrocer selling fruits and vegetables some 1,700 years ago in the city of Antioch, researchers find.

Written in Greek, the tablet holding the curse was dropped into a well in Antioch, then one of the Roman Empire's biggest cities in the East, today part of southeast Turkey, near the border with Syria.

The curse calls upon Iao, the Greek name for Yahweh, the god of the Old Testament, to afflict a man named Babylas who is identified as being a greengrocer. The tablet lists his mother's name as Dionysia, "also known as Hesykhia" it reads. The text was translated by Alexander Hollmann of the University of Washington.

The artifact, which is now in the Princeton University Art Museum, was discovered in the 1930s by an archaeological team but had not previously been fully translated. The translation is detailed in the most recent edition of the journal Zeitschrift für Papyrologie und Epigraphik.

"O thunder-and-lightning-hurling Iao, strike, bind, bind together Babylas the greengrocer," reads the beginning of one side of the curse tablet. "As you struck the chariot of Pharaoh, so strike his [Babylas'] offensiveness."

Hollmann told LiveScience that he has seen curses directed against gladiators and charioteers, among other occupations, but never a greengrocer. "There are other people who are named by occupation in some of the curse tablets, but I haven't come across a greengrocer before," he said.

The person giving the curse isn't named, so scientists can only speculate as to what his motives were. "There are curses that relate to love affairs," Hollmann said. However, "this one doesn't have that kind of language."

It's possible the curse was the result of a business rivalry or dealing of some sort. "It's not a bad suggestion that it could be business related or trade related," said Hollmann, adding that the person doing the cursing could have been a greengrocer himself. If that's the case it would suggest that vegetable selling in the ancient world could be deeply competitive. "With any kind of tradesman they have their turf, they have their territory, they're susceptible to business rivalry.”

The name Babylas, used by a third-century Bishop of Antioch who was killed for his Christian beliefs, suggests the greengrocer may have been a Christian. "There is a very important Bishop of Antioch called Babylas who was one of the early martyrs," Hollmann said.

Biblical metaphors

The use of Old Testament biblical metaphors initially suggested to Hollmann the curse-writer was Jewish. After studying other ancient magical spells that use the metaphors, he realized that this may not be the case.

"I don't think there's necessarily any connection with the Jewish community," he said. "Greek and Roman magic did incorporate Jewish texts sometimes without understanding them very well."

In addition to the use of Iao (Yahweh), and reference to the story of the Exodus, the curse tablet also mentions the story of Egypt's firstborn.

"O thunder—and-lightning-hurling Iao, as you cut down the firstborn of Egypt, cut down his [livestock?] as much as..." (The next part is lost.)

"It could simply be that this [the Old Testament] is a powerful text, and magic likes to deal with powerful texts and powerful names," Hollmann said. "That's what makes magic work or make[s] people think it works."

Jarus, Owen. 2012. "Deciphered Ancient Tablet Reveals Curse of Greengrocer". Live Science. Posted: December 21, 2011. Available online: http://www.livescience.com/17589-ancient-curse-translated-greengrocer.html

Wednesday, January 11, 2012

Towards a radical new approach to development aid

Development aid is in need of a major overhaul. This must include a better assessment of the priorities in specific developing countries: governance reforms designed to achieve a fairer distribution of income or economic reforms to increase growth. This is one of the important research conclusions reached by Rutger van den Noort, who will be awarded a PhD for his work on this subject on Thursday, 22 December at Delft University of Technology (TU Delft, the Netherlands).

Third World

Since 1952, developing countries have been classified as Third World countries. According to Rutger van den Noort, this classification has now become outdated because the differences between developing countries have increased significantly in the intervening years. 'As a result of this, there are now five clusters of countries, rather than three. The new classification takes account of differences between developing countries in terms of factors that are relevant today, such as the proportion of poor people in the population, the gross domestic product per head of population, energy consumption and labour productivity. Half a century ago, these factors did not seem important in the fight against poverty, but they are now essential in order to gain an effective understanding of what is and is not possible in developing countries.'


This new perspective clearly demonstrates that a 'one-size-fits-all' approach cannot be applied to development aid and highlights the necessity to first make an assessment, from a global perspective, in terms of what are known as the five Global Poverty Clusters (GPCs). Only then should there be a focus on a specific country in order to set priorities, argues Van den Noort.


In his thesis, Towards the end of global poverty, the TU Delft PhD student proposes a radical innovation of the development aid sector, based on this classification into GPCs, combined with what is known as the Cyclical Innovation Model. According to this model, it is necessary to coordinate three complimentary leadership tasks at the highest level: formulating a future vision (what do we want to achieve with the development aid sector?), developing a roadmap to achieve it (what approach will we adopt?) and applying a cyclic process model (how will we actually achieve these changes?).


The cyclic process model provides an outline of the related activities on which the development aid sector will need to focus. These are: conducting academic research into the technical and economic possibilities of the specific developing country; applying technologies that are appropriate for what may be limited infrastructure in that country; developing new products that are not only needed by the developing country itself, but will also enhance its competitive position and, finally, establishing trading relations in order to bring new products to the world market under fair and competitive conditions.


Van den Noort: 'This will make it possible for countries to develop their own knowledge economies, which can compete effectively in the global economy. Clearly, this new approach will call for a completely new skill set from the development aid sector. In this, the Cyclical Innovation Model will serve as a game-changer for the sector.'

EurekAlert. 2012. "Towards a radical new approach to development aid". EurekAlert. Posted: December 20, 2011. Available online: http://www.eurekalert.org/pub_releases/2011-12/duot-tar122011.php

Tuesday, January 10, 2012

Human skull study causes evolutionary headache

Scientists studying a unique collection of human skulls have shown that changes to the skull shape thought to have occurred independently through separate evolutionary events may have actually precipitated each other.

Researchers at the Universities of Manchester and Barcelona examined 390 skulls from the Austrian town of Hallstatt and found evidence that the human skull is highly integrated, meaning variation in one part of the skull is linked to changes throughout the skull.

The Austrian skulls are part of a famous collection kept in the Hallstatt Catholic Church ossuary; local tradition dictates that the remains of the town's dead are buried but later exhumed to make space for future burials. The skulls are also decorated with paintings and, crucially, bear the name of the deceased. The Barcelona team made measurements of the skulls and collected genealogical data from the church's records of births, marriages and deaths, allowing them to investigate the inheritance of skull shape.

The team tested whether certain parts of the skull – the face, the cranial base and the skull vault or brain case – changed independently, as anthropologists have always believed, or were in some way linked. The scientists simulated the shift of the foramen magnum (where the spinal cord enters the skull) associated with upright walking; the retraction of the face, thought to be linked to language development and perhaps chewing; and the expansion and rounding of the top of the skull, associated with brain expansion. They found that, rather than being separate evolutionary events, changes in one part of the brain would facilitate and even drive changes in the other parts.

"We found that genetic variation in the skull is highly integrated, so if selection were to favour a shape change in a particular part of the skull, there would be a response involving changes throughout the skull," said Dr Chris Klingenberg, in Manchester's Faculty of Life Sciences

"We were able to use the genetic information to simulate what would happen if selection were to favour particular shape changes in the skull. As those changes, we used the key features that are derived in humans, by comparison with our ancestors: the shift of the foramen magnum associated with the transition to bipedal posture, the retraction of the face, the flexion of the cranial base, and, finally, the expansion of the braincase.

"As much as possible, we simulated each of these changes as a localised shape change limited to a small region of the skull. For each of the simulations, we obtained a predicted response that included not only the change we selected for, but also all the others. All those features of the skull tended to change as a whole package. This means that, in evolutionary history, any of the changes may have facilitated the evolution of the others."

Lead author Dr Neus Martínez-Abadías, from the University of Barcelona's, added: "This study has important implications for inferences on human evolution and suggests the need for a reinterpretation of the evolutionary scenarios of the skull in modern humans."

EurekAlert. 2012. "Human skull study causes evolutionary headache". EurekAlert. Posted: December 20, 2011. Available online: http://www.eurekalert.org/pub_releases/2011-12/uom-hss122011.php

Paper Reference:

Martínez-Abadías, N.; Esparza, M.; Sjövold, T.; González-José, R.; Santos, M.; Hernàndez, M.; Klingenberg, C.P. "Pervasive genetic integration directs the evolution of human skull shape". Evolution, November 2011, DOI: 10.1111/j.1558-5646.2011.01496.x

Monday, January 9, 2012

Mystery Of Amazonian Tribe's Head Shapes Solved

Culture may trigger rapid evolution of various human features, suggests new research into the marital practices of a tribe from the Brazilian rainforest.

Evolution is often thought to be driven by environmental factors, including climate, or geographical obstacles such as rivers and mountains. Still, cultural factors — that is, groups of traditions and behaviors passed down from one generation to another — can have profound effects on behavior and also possibly lead to evolutionary changes.

To learn more, scientists analyzed genetic, climatic, geographic and physical traits of 1,203 members of six South American tribes living in the regions of the Brazilian Amazon and highlands. Their research found that one group, the Xavánte, had significantly diverged from the others in terms of their morphology or shape, possessing larger heads, taller and narrower faces and broader noses. These characteristics evolved in the approximately 1,500 years after they split from a sister group called the Kayapó, a rate that was about 3.8-times faster than comparable rates of change seen in the other tribes.

The major changes the investigators saw apparently occurred independently of the effects of climate or geography on the Xavánte. Instead, cultural factors appear responsible. For instance, in the Xavánte village of São Domingo, a quarter of the population was made up of sons of a single chief, Apoena, who had five wives. The tribe's sexual practices allow successful men in that group to father many offspring, which in turn means that any traits of theirs can quickly dominate their population.

"We have been working with the Xavante for about half a century, and from the beginning their morphology showed differences from the classical Amerindian pattern," researcher Francisco Salzano, a geneticist at Brazil's Federal University of the Rio Grande do Sul, told LiveScience. "We verified that the Xavante experienced a remarkable pace of morphological evolution."

The researchers suggest that assembling databases of cultural and biological data could help uncover other examples of how culture might influence human evolution.

"This specific piece of research is related to a long-term project of investigation involving not only the group responsible for this paper, but many others internationally," Salzano said.

Salzano and his colleagues detailed their findings online Dec. 19 in the Proceedings of the National Academy of Sciences.

Choi, Charles. 2012. "Mystery Of Amazonian Tribe's Head Shapes Solved". Live Science. Posted: December 19, 2011. Available online: http://www.livescience.com/17544-culture-human-evolution-amazon-tribe.html