'We're a culture, not a costume' this Halloween

Thinking about donning a kimono to dress like a geisha for Halloween, or a Mexican mariachi suit?

Students from Ohio University have a message for you: "We're a culture, not a costume."

With ethnic and racial stereotypes becoming increasingly popular Halloween costume themes, members of the school's Students Teaching About Racism in Society are launching a campaign to make revelers think twice before reducing a culture to a caricature, the group's president said.

Posters from the campaign are expected to go up on the Athens, Ohio, campus Wednesday. Meanwhile, the images are making the rounds online, raising debate over whether it's ever OK for people to paint their faces black, impersonate a racial stereotype for fun, and where to drawn the line.

It's a seasonal point of controversy, but even after widely publicized controversies such as the "Ghetto Fab" wig at Kohl's and Target's illegal alien jumpsuit, costumes of stereotypes abound. On Google's shopping section, several pages of "Mexican costume ideas" are available, from "Mexican donkey costumes" to sexy serapes and tequila shooter girls.

The ad campaign from Ohio University show students holding photos of different racial and ethnic stereotypes in costume: an Hispanic guy with a picture of the Mexican donkey costume, an Asian girl with an image of a Geisha, a Muslim student with a photo of a white guy wearing a traditional ghutra and iqal over his head, bombs strapped to his chest.

"During Halloween, we see offensive costumes. We don't like it, we don't appreciate it. We wanted to do a campaign about it saying, 'Hey, think about this. It's offensive,'" said senior Sarah Williams, president of STARS.

"The best way to get rid of stereotypes and racism is to have a discussion and raise awareness, which is what we want to do with this campaign," said Williams, who is black and plans on dressing as singer Janelle Monae for Halloween.

The most obvious offense occurs when someone who's not black decides to go blackface, because of the historical context, she said. But the message applies to all races and stereotypes -- and not just during Halloween.

The dean of students fully supported the campaign, calling it a "clean, succinct" way of delivering an important message.

"We've always tried to get a handle on what it means to be thoughtful and appropriate when it comes to talking to students about choosing costumes and making the best decisions for celebrating Halloween," Ryan Lombardi said.

"I think it's a clean way of raising awareness of how the costumes you choose might be offensive. In many cases, students aren't doing it maliciously, but they might not realize the consequences of their actions on others."

The campaign has gone viral, landing on blogs and other schools' online publications. So far, the response in the editorial sections has been positive. But in the comment sections, not everyone thinks it's a message that needs to be reinforced.

"Suddenly, I am overcome with the urge to dress up as the Frito Bandito this year," one comment on the Arizona Daily Wildcat's piece on the campaign said. "Guys & girls -- Halloween is just bit of fun. Dead guys don't come back to life and eat people. There are no hot blonde lady cops in tiny uniforms that demand to 'frisk' you. Kimonos are OK even if 'Asians' don't wear them on a daily basis."

But others think it's a message that needs to be repeated.

"I think it's almost impossible to be ironic while being racist, so irony is lost," said Jelani Cobb, a professor of Africana studies at Rutgers University and the author of "The Substance of Hope: Barack Obama and the Paradox of Progress."

"To treat a character like Batman or Superman as a Halloween costume is one thing, but to treat an entire ethnicity as a costume is something else. It suggests that people conflate the actual broad diversity of a culture with caricatures and characters."

While Italian-Americans can be stereotyped as gangsters and Irish-Americans as hard drinkers, there are no pervasive stereotypes for whites on the same level that allow for them to be caricatured as a Halloween costume, Cobb said.

"The more we look at people as caricatures, the harder it is to operate as democracy," he said. "What underlies this kind of costuming is the belief that these people aren't quite equal to what we are or aren't as American as we are, or that you as a person who's not a member of that group should be able to dictate how painful the stereotype should be."


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References:

Grinberg, Emanuella. 2011. "'We're a culture, not a costume' this Halloween". CNN Living. Posted: October 26, 2011. Available online: http://www.cnn.com/2011/10/26/living/halloween-ethnic-costumes/index.html

Couple Held Hands for 1,500 Years

The man and woman were likely buried facing each other in Italy in the 5th century A.D.



The skeletal remains of a Roman-era couple reveal the pair has been holding hands for 1,500 years.

Italian archaeologists say the man and woman were buried at the same time between the 5th and 6th century A.D. in central-northern Italy. Wearing a bronze ring, the woman is positioned so she appears to be gazing at her male partner.

"We believe that they were originally buried with their faces staring into each other. The position of the man's vertebrae suggests that his head rolled after death," Donato Labate, the director of the excavation at the archaeological superintendency of Emilia-Romagna, told Discovery News.

The tender discovery was made during ordinary construction work in Modena and was announced this week. Labate explained the dig revealed three layers of scientific interest.

The deeper layer, some 23 feet below the surface, contained the remains of Roman-era structures, including a calcara where mortar was produced. The ruins belonged to the suburbs of Modena, then called Mutina.

"A middle layer, at a depth of about 10 feet, featured 11 burials, while a third stratification on top of the necropolis, revealed seven empty tombs," Labate said.

Excavated by archaeologist Licia Diamanti, the skeleton couple belonged to the 11 tomb necropolis. According to Labate, the simple fossa (trench) tombs suggest that the people buried there were not particularly rich.

"They were possibly the inhabitants of a farm," Labate said.

The area was subjected to several floods from the nearby river Tiepido -- which may have caused the male skeleton's skull to roll away from the female skeleton after burial. The necropolis was covered by alluvial deposits, and on top of them, another seven tombs were built.

"These burials were empty. Most likely, they were covered by another flood just after their construction. We think it was a catastrophic flood which occurred in 589, as reported by the historian Paul the Deacon," Labate said.

The two skeletons, which are poorly preserved, will be now studied by Giorgio Gruppioni, an anthropologist at the University of Bologna. The research includes establishing the couple's age, their relationship and the possible cause of death.

"In antiquity, it is not surprising to learn of spouses or members of a family dying at the same time: whenever epidemics such as the Black Plague ravaged Europe, one member of the family would often die while the family was trying to bury another member," Kristina Killgrove, a biological anthropologist at the University of North Carolina, told Discovery News.

In 2007 another skeleton couple, buried between 5,000 and 6,000 years ago, was found at a neolithic site near Mantua, just 25 miles south of Verona, where Shakespeare set the romantic story of Romeo and Juliet.

Locked in a tender embrace, they also looked at one another in apparent defiance of time and decay.

"The two couples are separated in time by five millennia, and both evoke an uplifting tenderness. I have been involved in many digs, but I've never felt so moved," Labate said.

According to Killgrove, the positioning of the Modena skeletons, looking at one another and holding hands, indeed suggests they may have been a couple.

"Whoever buried these people likely felt that communicating their relationship was just as important in death as it was in life," Killgrove said.
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References:

Lorenzi, Rossella. 2011. "Couple Held Hands for 1,500 Years". Discovery News. Posted: October 21, 2011. Available online: http://news.discovery.com/history/skeletons-lovers-ancient-italy-111021.html

Face-to-face with an ancient human

A reconstruction based on the skull of Norway's best-preserved Stone Age skeleton makes it possible to study the features of a boy who lived outside Stavanger 7,500 years ago

The Viste Boy represents the most complete Norwegian Stone Age skeleton. Now Norway's most extensive reconstruction of a Stone Age skeleton has now been achieved.

"It is hoped that this reconstruction is a good likeness and that, if someone who knew him in life had been presented with this restoration, they would hopefully have recognised the face", says Jenny Barber, an MSc student at the University of Dundee in Scotland.

She has scientifically rebuilt the face of the strong and stocky Viste Boy, who lived in the Vistehola cave near Stavanger, so that people can now look him right in the eye.

Ms Barber is studying forensic art, an unusual discipline embracing such elements as human anatomy and identification in order to recreate the appearance of an actual person.

This modelling method is primarily employed to assist police investigations, and is little known or used in Norway. But the country's most extensive reconstruction of a Stone Age skeleton has now been achieved.

Complete

Discovered in 1907, the Viste Boy represents the most complete Norwegian Stone Age skeleton and the third oldest human remains ever found in the Norway.

His dark-coloured skull and bones are currently on display in a glass case at the Archaeological Museum on the University of Stavanger (UiS).

Analyses show that the Viste Boy was approximately 15 when he died. He stood a bit less than 1.25 metres tall and probably lived in a group of 10-15 people.

From their studies of rubbish in and around Vistehola, the archaeologists determined that this clan ate fish – mostly cod – as well as oysters, mussels, cormorants, elk and wild pig.

They also thought that the teenager might have been sickly, which would explain his early death.

Woman

The oldest of Norway's known skeletons from the Stone Age belonged to a woman and was discovered at Søgne near Kristiansand in 1994. Her skull has been dated to 8 600 years ago.

She was the subject of Norway's first and hitherto only reconstruction of such ancient bones, which was exhibited at the University of Oslo's Museum of Art History in 1997.

This model was based on data from a series of skull X-rays, which allowed specialists at University College in London to build a three-dimensional recreation.

But reconstruction techniques are steadily improving, and the model of the Viste Boy reproduces his features differently than with the Søgne woman.

"The goal has been to create something as similar as possible to the original," explains Ms Barber. "That's what facial reconstruction is all about – identification and recognition of a unique person."

Scanned

She has scanned the skull belonging to the long-dead youth with a laser surface scanner, which provided accurate data on his anatomy.

The cranium had suffered some damage, so the most complete side was duplicated. To support her work, Ms Barber also drew on a digital copy of the skull of another 15-year-old boy.

Nevertheless, the final anatomy corresponds to all intents and purposes with the original bone.

After her programming, Ms Barber could convert the digital construct into a plastic model and then shape muscle, skin and features in clay.

The clay bust formed the basis for a negative mould, with the finished product then cast in plastic resin and fibreglass. Eyes, ears and other details were finally painted or added.

Deformity

Ms Barber's work revealed that the Viste Boy had scaphocephaly ("boat-head"), a congenital deformity which makes the skull long and narrow. She left the modelled head hairless to show this.

"The fact that the boy had scaphocephaly is a medical detail we hadn't observed before," says Mads Ravn, head of research at the Archaeological Museum.

He is very enthusiastic about the job Ms Barber has done, and points to similar work at Denmark's Moesgård Museum to reconstruct the Grauballe Man – a body recovered from a Danish bog.

He turned out to have a very protruding jaw and close-set eyes, which prompted the theory that he was an executed outcast or criminal, rather than a rich man sacrificed to the gods.

It was also clear that – like the Tollund Man, another "bog body" – resembled many contemporary Danes.

The work done by Ms Barber on the Viste Boy also demonstrates that the stocky lad was no weakling.

"This reconstruction indicates that he must have been muscular, quite simply a robust person," she observes. "So it's not certain that he was sickly, as people have thought.

"The bone analysis doesn't bear out such a diagnosis, and he has no other deformities that we know of other than the scaphocephaly."

Great

Apart from the more scientific findings, such as the scaphocephaly and the good muscles, Mr Ravn thinks it is great to be able to look such a remote forefather in the eye.

"Just imagine, we can get an idea of how the oldest Norwegian man looked."

He is also very pleased at the opportunities this reconstruction opens up for the museum.

"Our challenge in older archaeology is to present the finds in a good way. Ms Barber's work has given us a fantastic chance to convey flesh and blood through a very ancient relic."

The project is part of the Scientific Archaeological Laboratory research programme at the UiS, which emphasises lab work in cooperation with the museum's Department of Education and Visitor Service.

Ms Barber herself stresses the educational aspect as an important motivation for her work.

"People are drawn to faces. The Viste Boy will probably attract attention in a future exhibition at the museum, bringing the story of Vistehola, the Viste Boy and the other people who lived there more alive for visitors."

She adds that facial reconstruction has been used for educational purposes by museums in many parts of the world, but is not used to any great extent at Norwegian institutions.

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References:
Okstad, Karen Anne. Rolf Gooderham, Trans. 2011. "Face-to-face with an ancient human". EurekAlert. Posted: Available online: http://www.eurekalert.org/pub_releases/2011-10/uos-fwa102011.php

Pentagon cultural analyst helped with interrogations

'Experiment' raises alarm among social scientists.

The Pentagon's forays into social science — what the military calls "human terrain" — have raised ethics concerns among academics. But now, a cultural analyst working as a contractor for the military has said that she helped to interrogate detainees in Afghanistan.

Cultural expertise was "key in the support I was providing to the interrogator to develop a relationship with the detainee", said Julia Bowers, principal senior analyst for human terrain at SCIA, a company based in Tampa, Florida, that provides socio-cultural services for the military and intelligence community, at a conference in San Antonio, Texas, on 16 October.

"Typically human-terrain analysis is more of a human data-gathering and mapping approach," Bowers said, but in this job, her remit was more to help the interrogator to gain the detainee's trust. The programme was experimental and ran "for just a few months", she said.

Bowers worked with the US Central Command's human terrain analysis branch, which is separate from the army's Human Terrain System (HTS), a better known programme that embeds social scientists within the military. Both, however, are designed to provide the military with better cultural understanding and expertise.

The HTS, started in 2006, actively recruits from academia and now has 31 teams deployed in Afghanistan. It was initially embraced by senior Pentagon officials, including former defence secretary Robert Gates, but has been dogged by controversy after the injury and death of several social scientists.

In one of the more dramatic incidents, a team member was convicted of manslaughter for killing an Afghan detainee who had set a social scientist on fire. The social scientist later died of her wounds.

The Human Terrain Analysis Branch, by contrast, has kept a much lower profile, though it is also uses social science to collect cultural and ethnographic information for the military in Afghanistan and around the region.

Levels of advice

The American Anthropological Association in Arlington, Virginia, has a rapid response network of individuals dedicated to advising the organisation on the ethical concerns of anthropologists working with the military. The network was faced with the interrogation issue early on, says Hugh Gusterson, an anthropologist at George Mason University in Fairfax, Virginia, who is part of the network. But the issue then was whether they should advise on interrogation policy, not whether anthropologists should actually participate in interrogations.

"Advising people on how to extract information from people who don't want information extracted, that is the antithesis of what the anthropological encounter is supposed to look like," says Gusterson. "It's inherently unethical to me."

So far, the HTS has been involved in interrogations in just one experiment. A former employee of the HTS, who asked not to be identified, says that they learned in 2009 that HTS personnel were involved at one point in interrogations in Afghanistan. "I sent it up the chain at Fort Leavenworth; they knew about it," the employee says. "It struck me as blatantly unethical. I didn't want anything to with it."

The employee, who describes the work as "the exact opposite of what the programme says it is", left the HTS shortly after voicing their concerns.

Retired Army Col. Steve Fondacaro, who headed HTS until he was ousted in a management shakeup last year notes that all the units that HTS teams support are involved in interrogations. "Our team members may have been asked to help or advise in any or all of these areas where it related to greater insight and understanding of the population," he wrote in an email. "But it did not result in any of these operation becoming core mission capabilities HTS focused upon."

But Sharon Hamilton, head of the programme, says that HTS personnel have not worked with interrogators, at least in the year-and-a-half she's been there. "We have a strict rule and the units understand this," she says. "HTS teams are never used with people who cannot provide informed consent. Informed consent obviously, by its very nature, cannot be given by a detainee."
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References:

Weinberger, Sharon. 2011. "Pentagon cultural analyst helped with interrogations". Nature. Posted: October 18, 2011. Available online: http://www.nature.com/news/2011/111018/full/news.2011.598.html

Rebuilding the genome of a hidden ethnicity

Participants in the 1000 Genomes project reconstruct the genetic variation of a Native American tribe from their descendants.

The Taínos were the first Native Americans to meet European explorers in the Caribbean — and they soon fell victim to the diseases and violence brought by the outsiders. Today, the genomes of most if not all descendents of Taínos now contain few of the unique markers that characterized their ancestors.

But the genetic footprints of these ancestors are scattered throughout the genomes of modern Puerto Ricans, according to geneticist Carlos Bustamante at the Stanford University School of Medicine in Stanford, California. On average, the genomes of Puerto Ricans contain 10–15% Native American DNA, which is largely Taíno, says Bustamante.

At a presentation at the 12th International Congress of Human Genetics in Montreal, Canada, Bustamante described preliminary results from a study that aims to reconstruct the genetic features of the Taíno people. The cryptic information was found in the genomes of 70 modern Puerto Ricans, some of the latest additions to the ongoing 1000 Genomes project, an international consortium whose goal is to find the variations in DNA sequence among the genomes of all human populations.

Window on the past

The genomes of modern Puerto Ricans are a mosaic of African, European and Native American sequences. A set of single-nucleotide locations that are known to vary across these different ancestral groups helped Bustamente and his collaborators to identify whether a given region of the genome was African, European or Native American in origin, and thus begin to stitch together chromosomal segments corresponding to the Taíno heritage. The various Taíno sequences in the 70 different genomes will help to build a more complete picture of the ancestral Native American genomes.

The project has also shed light on the history of interactions between Native Americans, Africans and Europeans in the Caribbean. To infer when the various populations interbred, the team first estimated the lengths of each segment of African, European and Native American DNA in the modern genomes. They found the Taíno segments to be relatively short, suggesting a single 'pulse' of admixture — the result of interbreeding between populations — a few hundred years ago.

The small size of the ancestral segments fits with our understanding of the history of Puerto Rico, says Marc Via, a molecular anthropologist at the University of Barcelona, Spain, who was not involved in the study. "The admixture took place suddenly, so most of the population mixed with the African slaves and European settlers in the very early colonization of Puerto Rico." With every generation, the segments of Taíno genome would become smaller and smaller, he says.

Unlike the rapid mixing of Taíno with African and European genomes, the slave trade created a more complex pattern of African sequences. "The African and European segments have a fair amount of variation in size, which tells us that they are the result of several waves of migration," says Bustamante. Early insights from the study suggest that shorter, and therefore older, African segments come from populations near the coast of Senegal, whereas longer, more recent, segments come from inland African populations. This suggests that slave-traders first captured slaves on the coast but later had to go inland.

Tracking the slave trade

This information is key to understanding the history of the slave trade and African American history, says Bustamante. "Most Africans Americans in the United States have ancestry that largely traces to the African slaves that came through the Caribbean," he says. "We would love to be able to give folks back historical information that can be derived from DNA sequence data about where people came from."

The study, which includes collaborators at the University of Puerto Rico in Mayagüez, will also help address deficiencies in medical genetics data sets, which largely contain sequences of European origin1. "This now opens up the opportunity to undertake large-scale medical genetic studies in Puerto Ricans and in other populations of Afro-Caribbean and Hispanic-Latino descent."
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References:

Young, Susan. 2011. "Rebuilding the genome of a hidden ethnicity". Nature. Posted: October , 2011. Available online: http://www.nature.com/news/2011/111014/full/news.2011.592.html

Digability: Inclusive archaeology

A major new archaeology project, starting in October 2011, has been awarded £200,000* by the Heritage Lottery Fund (HLF).

To be run by the Workers’ Educational Association (WEA), the three year region-wide initiative has been launched in time for Disability History Month in November, and will enable 300 people who would not usually be given the chance to take part in an archaeology dig the chance to get out in the field, learn new skills and have fun uncovering Yorkshire’s fascinating historic past.

The scheme will target a variety of groups including adults with learning difficulties, mental health issues, and physical disabilities as well as those from under-represented ethnic minority communities from across Yorkshire and the Humber. Sites expected to take part include:

* Sheffield Manor Lodge
* The Iron Age Roundhouse at Heeley City Farm, Sheffield
* Romano-British settlements in Chapel House Wood, Wharfedale
* Medieval field systems in North Killingholme near the Humber
* Conisbrough Castle, near Doncaster, South Yorkshire

Fiona Spiers, Head of the Heritage Lottery Fund for Yorkshire and the Humber, said: “This is a fantastic and wide-reaching scheme that aims to improve access to archaeology projects for under-represented groups. There is a myriad of benefits to be gained from getting involved in archaeology from strengthening communities to learning new skills, learning how to be part of a team to helping to uncover Yorkshire’s rich history for future generations.“

This important scheme has been developed to meet the needs identified by the Council for British Archaeology (CBA) statement that it is vital work is done ‘to develop more positive action to challenge the perceptual, social or economic barriers that tend to exclude disabled people, ethnic minorities and people from economically and socially deprived areas from direct engagement in archaeology.’

Rob Hindle, Project Manager, WEA, explained further how the project will benefit people: “Heritage is a collective historical legacy: shaped by the totality of people inhabiting the region throughout its history, it belongs to everyone, whatever their background, experience or circumstances. This project will provide an opportunity to demonstrate that everyone can play a role in its interpretation, celebration and conservation.”

Entitled the Inclusive Archaeology Education Project the WEA initiative will involve 1,200 hours of classroom and outdoor teaching over three years. The project will start with an introduction to archaeology through practical, hands-on tasks and visits to heritage sites locally, followed by field-based activities at identified archaeological sites.

Engaging learners through a range of innovative activities including ‘a history of ourselves in 300 objects’ (inspired by the BBC Radio series‘A History of the World in 100 objects’), the scheme will offer participants the chance to develop key skills such as object handling and identification, using photographs, surveying and mapping, scale drawing, test pitting, finds processing and analysis, and group presentation.

The project will also offer local university archaeology students the opportunity to undertake the WEA taught City and Guilds qualification, ‘Preparing to Teach in the Lifelong Learning Sector’ and to undergo additional training related to the participants needs.
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References:

Past Horizons. 2011. "Digability: Inclusive archaeology". Past Horizons. Posted: October 14, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/10/2011/digability-inclusive-archaeology

African cave's ancient ochre lab

Find suggests that Stone Age sophistication extends further back than thought.

Stone Age humans had an elementary knowledge of chemistry. Archaeologists have found evidence that, as long ago as 100,000 years, people used a specific recipe to create a mixture based on the iron-rich ochre pigment.

The findings, published in the journal Science¹, "push back by 20,000 or 30,000 years" the evidence for when Homo sapiens evolved complex cognition, says Christopher Henshilwood of the universities of Bergen in Norway and Witwatersrand in Johannesburg, South Africa, who led the work.

"This isn't just a chance mixture, it is early chemistry. It suggests conceptual and probably cognitive abilities which are the equivalent of modern humans," he says.

Lyn Wadley, an archaeologist at the University of the Witwatersrand who was not involved in the research, adds that it implies that people at that time could "think in abstract terms" about the quality and quantity of their ingredients. "Making compounds of any kind implies complex cognition," she says.

The discovery, in 100,000-year-old sediments at the Blombos Cave on South Africa's southern tip, entails two abalone shells lined with a red compound consisting of ochre, bone and charcoal. The raw ingredients, along with hammers, grindstones and a bone stirrer, were found nearby, indicating the existence of an early workshop for producing the mixture.

This is not the earliest evidence that humans used ochre, says Henshilwood, but it is the first evidence for how they combined the pigment after grinding it up. "The components in both of the shells are the same, so they knew what they were doing," he adds.

Painting the cave red

Anatomically modern humans are thought to have lived in Africa from about 200,000 years ago², but when people acquired advanced mental abilities is a matter of intense debate.

Previous evidence, such as shell beads, ochre engravings and ancient glue from various middle Stone Age sites, indicates that humans had evolved complex cognition by between 80,000 and 70,000 years ago. Henshilwood's finding stretches that further.

It also provides the earliest evidence for the use of containers, pre-dating previous examples³ by 40,000 years, says Henshilwood. The abalone shells' respiratory holes would probably have been plugged to contain the liquid mixture.

Archaeologist Graeme Barker at the University of Cambridge, UK, describes the discovery as a "neat and evocative addition to the gathering information on the behavioural complexity of early Homo sapiens ".

The mixture's purpose is unknown, but the authors speculate that it might have been used as a paint to protect or decorate human skin, artefacts or cave walls. They think that the ochre, which was probably brought to the cave from the nearest source 20–30 kilometres away, was rubbed on quartzite slabs to produce a fine red powder. Next, the authors propose, it was added to the shell containers along with crushed and heated fat-rich mammal bone, charcoal and a liquid, and stirred before use.

Wadley questions whether the recipe was for an art material. Ochre-based glues used to attach stone tools to handles have previously been found⁴ and the ingredients here seem suitable for a simple adhesive, she says.

But Henshilwood believes paint rather than glue is "much more" likely. No evidence was found of any resin, necessary to make the mixture sticky, he notes.
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References:

Corbyn, Zoë. 2011. "African cave's ancient ochre lab". Nature. Posted: October 13, 2011. Available online: http://www.nature.com/news/2011/111013/full/news.2011.590.html

Article References:

1. Henshilwood, C. S. et al. Science 334, 219-222 (2011).
2. McDougall, I., Brown, F. H. & Fleagle, J. G. Nature 433, 733-736 (2005).
3. Wadley, L. J. Archaeol. Sci. 37, 2397-2406 (2010).
4. Wadley, L., Hodgskiss, T. & Grant, M. Proc. Natl Acad. Sci. USA 106,
9590-9594 (2009).

The seaweed trail: Peopling the Americas

Mapmakers once thought the earth was flat. Astronomers used to believe the sun circled the earth. As late as the 1990s, archaeologists were convinced that the original American settlers crossed a land bridge from Asia into Alaska, found daylight between the glaciers, and gradually followed it south. According to what had been orthodox thinking, that happened about 12,000 years ago.

“Suppose it were true,” says Jack Rossen, associate professor and chair of the Department of anthropology. “Suppose you could find a corridor through a mile-high wall of ice and follow it for a thousand miles. What would you eat? Popsicles?”

A practical alternative

There are seaweed belts along the western coast of the Americas, from Alaska to Chile, and they’re as ecologically complex as rain forests,” he says. “There are canopy species of animals, species of animals beneath the canopy, including fish, and there’s the seaweed itself, which is incredibly rich in nutrients. What would people rather do? Try to find a meal in a world of ice, or take a boat down the coast and help themselves to fish, oysters, and greens?”

In retrospect, the seaweed trail makes sense. But as recently as 15 years ago, it was archaeological heresy to think that North and South America’s first humans didn’t use the land route. The evidence for that conventional wisdom came from a site excavated in the 1930s near what is now Clovis, New Mexico. According to carbon dating, the stone spear points discovered there were 11,200 years old, making Clovis the oldest known settlement in the Americas. The assumption was that hunter-gatherers from Asia had hiked south from the Bering land bridge, living off the occasional mastodon and whatever else they could find.

But in 1975 a visiting veterinary student came across what he thought was a cow bone exposed along a creek bed in southern Chile, some 50 miles from the Pacific coast. When the “bone” turned out to be a mastodon tusk, Tom Dillehay, a renowned archaeologist then at the University of Kentucky (now at Vanderbilt University), and his Chilean colleagues realized they had a prehistoric site on their hands. In 1976 the Dillehay team began an excavation project in Monte Verde, Chile, that would occupy them for the next nine years. In 1983 Dillehay asked one of his dissertation advisees — Jack Rossen — to join the dig.

“He wanted me along because I knew how plant use among ancient cultures — both as food and medicine — reveals how those communities are organized,” Rossen says. “That background was important at Monte Verde because Tom knew the site was going to contain a fair amount of preserved plant life.”

“A fair amount” turned out to be 72 different kinds of plants, including seeds, nuts, berries, and a specimen of wild potato carbon dated at 13,000 years old. “That kind of abundance,” says Rossen, “is unheard of in archaeological science.”

In addition to the plants, Dillehay’s team found a 20-foot long tentlike structure of wood and animal hides, a human footprint small enough to be a child’s, two outdoor hearths, more than 700 finely crafted bone and stone tools, and hundreds of other artifacts.

Not only was the abundance of the findings extraordinary, so was their state of preservation. Normally, plants and other organic materials break down over time, but fallen logs had dammed the creek along which the settlement was founded. Peat moss began building up, and within months the site turned into a bog and had to be abandoned. An air-tight insulator, the peat kept biodegradable material from decaying. Dillehay and his researchers found themselves excavating a mummified village.

“Everything was preserved,” Rossen says. “We used dental picks to excavate it, that’s how meticulous we were.”

A medicine hut provides a clue

That attention to detail paid off. On the floor of what had been a wishbone-shaped structure, Rossen and his colleagues uncovered scatterings of bite-sized lumps shaped like half moons.

“The wishbone structure was most likely a medicine hut,” Rossen says. “And the lumps turned out to be chewed cuds containing five species of seaweed mixed with a variety of purgatives, antibiotics, and other medicinal plants.”

That was remarkable, Rossen says, because at the time of its habitation, Monte Verde was 50 miles from the nearest sea coast. More remarkable: some of the seaweed was from rocky coasts, some from sandy coasts, and some of the plants came from as far as 250 miles away. Even more remarkable: the array of plants
included species that weren’t available year-round. They’d been harvested at different times of the year.

“That’s how we know the people who settled Monte Verde stayed there all year long,” Rossen says. “That also tells us they weren’t colonizers because people who are just settling into a place don’t have detailed knowledge of their surroundings. Nor do they have the kinds of established social and trade networks that can bring in plant species from remote locations. The people who lived at Monte Verde had been there a while.”

How long was “a while”? According to the carbon-dated objects at the site, at least 12,500 years. Aha! A human settlement was thriving in southern Chile 500 years before the first settlers were supposed to have crossed a land bridge 10,000 miles to the north.

“Finding a site older than Clovis was a complete paradigm shift, and a lot of people didn’t want to go along with it,” Rossen says. “Showing that humans had been living in the Americas a lot longer than anyone imagined was very controversial and required a very high standard of proof.”

That standard included a 1,000-page research report circulated among leading archaeologists. For years, experts scrutinized the data from the Monte Verde digs, and in 1997, after what Pulitzer Prize–winning journalist John Noble Wilford called “a pitched intellectual battle. . . over when people first inhabited the Americas,” a team of archaeologists sponsored by the National Geographic Society and Dallas Museum of Natural History visited the site. The report they issued vindicated the findings at Monte Verde.

“Monte Verde is real,” wrote Alex W. Barker, chief curator of the Dallas Museum of Natural History. “It’s old. And it’s a whole new ball game.”

Since then, about 25 sites — including two in Brazil and another on an island off the California coast — have been discovered that also pre-date Clovis. In addition, objects from a deeper layer at Monte Verde have been carbon dated to be nearly 33,000 years old. In other words, people were established in South America almost 22,000 — not just 1,300 — years before Clovis.

In case anyone’s still not totally convinced, evidence from those digs in the 1980s is still coming in. In the May 2008 issue of Science, an article co-authored by Dillehay, Rossen, and others presented a recently completed study of nine species of seaweed found at Monte Verde, including microscopic particles ingrained along the edge of a stone tool. The study confirmed the original findings.

“Originally, we collected more material than we had time to study,” Rossen says. “But archaeological projects never end. The analysis continues years after the excavations are done. There’s always something more you can do with the material.”

A convincing route

Though archaeologists are now convinced of the coastal route, they’re still sorting out the details. For example, where and how did those early hunter-gatherers stop floating down the coast, foray inland, and settle? It’s hard to tell, since sea levels have risen over the millennia. Sites where ancient people could have established coastal communities are now 200 feet under water. The step-by-step movements of ancient Americans may never be precisely mapped, but Rossen isn’t discouraged.

“Knowing how these people lived is more important than knowing every detail of how they got there, because ancient people have a lot to teach us,” he says. “During 99 percent of our history, humans have been hunter-gatherers — or more accurately, gatherer-hunters — and we’re still that way at heart. We may live in large cities, but we still function best in groupings of 15 to 20 people. And the way we run errands — finding where the bargains are, who has the best service, where the best food is — replicates the behaviour patterns of people who know where to go when potatoes are in season, where the best wood is, and which berries to pick.”

Ancient people can also teach us a thing or two about medicine.

“Some of the plants we found at Monte Verde are currently being used in commercial cough syrup,” Rossen says. “Also, because a lot of the food plants used at Monte Verde have an amazingly high nutritional value, those nutrients can treat contemporary people suffering from vitamin deficiencies.”

Among those plants: seaweed.

“Seaweed fills the same nutritional gaps now as it did 20,000 years ago,” Rossen says. “I recommend it. It tastes great.”
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References:

Davis, Keith. 2011. "The seaweed trail: Peopling the Americas". Past Horizons. Posted: October 12, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/10/2011/the-seaweed-trail-peopling-the-americas

A henge beneath the water of the stenness loch? Time will tell

Survey work in the Loch of Stenness has revealed what could be a massive prehistoric monument lying underwater to the south of the Ring of Brodgar.



The underwater “anomaly” has come to light in a project looking at prehistoric sea level change in Orkney. The project, The Rising Tide: Submerged Landscape of Orkney, is a collaboration between the universities of St Andrews, Wales, Dundee, Bangor and Aberdeen.

But although it is tempting to speculate that the ring-shaped feature, which lies just off the loch’s shore, is the remains of a henge — a circular or oval-shaped flat area enclosed and delimited by a boundary earthwork (usually a ditch with an external bank) — or perhaps a prehistoric quarry, at this stage the project leaders are urging caution.

Orkney-based archaeologist, Caroline Wickham-Jones, a lecturer at the University of Aberdeen, explained: “The preliminary results from the high-resolution geophysical sensing are suggesting that there is an unusual ‘object’ in the shallow water just off the shore, but more work is needed before we can identify it or even confirm whether it is a natural, perhaps geological, feature, or something man-made.”

When prehistoric Orcadians started to build the stone circles in Stenness, the landscape would have been much different to what it is today and the sea would have been about a metre below current levels. Prior to the sea coming in, the loch area was stands of open freshwater, with reed beds — probably much like the landscape around the Loons, in Birsay, today.

Previous studies have shown that the sea around Orkney reached its present level about 2000BC, but even then, because there is a rock “lip” at the Brig o’ Waithe which held the sea back, the impact of the rising water in the Loch of Stenness was a bit slower.

Caroline Wickham-Jones added, “Archaeologists study what’s there, but sometimes it’s more interesting to ask what’s not there. The early Neolithic tombs around the bay for example: where are they? Many other early Neolithic tombs in Orkney — such as Unstan — are found near present sea level, on low-lying land. Were the earliest tombs around the Bay of Firth built on land that has since been covered by sea?”

The surveys have detected two intriguing anomalies in the bay, one of which is visible in aerial photographs by the Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) and also appears on the remote sensing results.

A seismic survey in the bay has helped to shed light on the possible structure of one of these, and now the team plans more diving work to confirm the results.

Read the original story at the Orkney Jar
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References:

Past Horizons. 2011. "A henge beneath the water of the stenness loch? Time will tell". Past Horizons. Posted: October 12, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/10/2011/a-henge-beneath-the-water-of-the-stenness-loch-time-will-tell

Early Celtic 'Stonehenge' Discovered in Germany's Black Forest

A huge early Celtic calendar construction has been discovered in the royal tomb of Magdalenenberg, nearby Villingen-Schwenningen in Germany's Black Forest. This discovery was made by researchers at the Römisch-Germanisches Zentralmuseum at Mainz in Germany when they evaluated old excavation plans. The order of the burials around the central royal tomb fits exactly with the sky constellations of the Northern hemisphere.

Whereas Stonehenge was oriented towards the sun, the more than 100 meter width burial mound of Magdalenenberg was focused towards the moon. The builders positioned long rows of wooden posts in the burial mound to be able to focus on the Lunar Standstills. These Lunar Standstills happen every 18,6 year and were the 'corner stones' of the Celtic calendar.

The position of the burials at Magdeleneberg represents a constellation pattern which can be seen between Midwinter and Midsummer. With the help of special computer programs, Dr. Allard Mees, researcher at the Römisch-Germanischen Zentralmuseum, could reconstruct the position of the sky constellations in the early Celtic period and following from that those which were visible at Midsummer. This archaeo-astronomic research resulted in a date of Midsummer 618 BC, which makes it the earliest and most complete example of a Celtic calendar focused on the moon.

Julius Caesar reported in his war commentaries about the moon based calendar of the Celtic culture. Following his conquest of Gaul and the destruction of the Gallic culture, these types of calendar were completely forgotten in Europe. With the Romans, a sun based calendar was adopted throughout Europe. The full dimensions of the lost Celtic calendar system have now come to light again in the monumental burial mound of Magdalenenberg.
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References:

Science Daily. 2011. "Early Celtic 'Stonehenge' Discovered in Germany's Black Forest". Science Daily. Posted: October 11, 2011. Available online: http://www.sciencedaily.com/releases/2011/10/111011074624.htm

Hearing Bilingual: How Babies Sort Out Language

Once, experts feared that young children exposed to more than one language would suffer “language confusion,” which might delay their speech development. Today, parents often are urged to capitalize on that early knack for acquiring language. Upscale schools market themselves with promises of deep immersion in Spanish — or Mandarin — for everyone, starting in kindergarten or even before.

Yet while many parents recognize the utility of a second language, families bringing up children in non-English-speaking households, or trying to juggle two languages at home, are often desperate for information. And while the study of bilingual development has refuted those early fears about confusion and delay, there aren’t many research-based guidelines about the very early years and the best strategies for producing a happily bilingual child.

But there is more and more research to draw on, reaching back to infancy and even to the womb. As the relatively new science of bilingualism pushes back to the origins of speech and language, scientists are teasing out the earliest differences between brains exposed to one language and brains exposed to two.

Researchers have found ways to analyze infant behavior — where babies turn their gazes, how long they pay attention — to help figure out infant perceptions of sounds and words and languages, of what is familiar and what is unfamiliar to them. Now, analyzing the neurologic activity of babies’ brains as they hear language, and then comparing those early responses with the words that those children learn as they get older, is helping explain not just how the early brain listens to language, but how listening shapes the early brain.

Recently, researchers at the University of Washington used measures of electrical brain responses to compare so-called monolingual infants, from homes in which one language was spoken, to bilingual infants exposed to two languages. Of course, since the subjects of the study, adorable in their infant-size EEG caps, ranged from 6 months to 12 months of age, they weren’t producing many words in any language.

Still, the researchers found that at 6 months, the monolingual infants could discriminate between phonetic sounds, whether they were uttered in the language they were used to hearing or in another language not spoken in their homes. By 10 to 12 months, however, monolingual babies were no longer detecting sounds in the second language, only in the language they usually heard.

The researchers suggested that this represents a process of “neural commitment,” in which the infant brain wires itself to understand one language and its sounds.

In contrast, the bilingual infants followed a different developmental trajectory. At 6 to 9 months, they did not detect differences in phonetic sounds in either language, but when they were older — 10 to 12 months — they were able to discriminate sounds in both.

“What the study demonstrates is that the variability in bilingual babies’ experience keeps them open,” said Dr. Patricia Kuhl, co-director of the Institute for Learning and Brain Sciences at the University of Washington and one of the authors of the study. “They do not show the perceptual narrowing as soon as monolingual babies do. It’s another piece of evidence that what you experience shapes the brain.”

The learning of language — and the effects on the brain of the language we hear — may begin even earlier than 6 months of age.

Janet Werker, a professor of psychology at the University of British Columbia, studies how babies perceive language and how that shapes their learning. Even in the womb, she said, babies are exposed to the rhythms and sounds of language, and newborns have been shown to prefer languages rhythmically similar to the one they’ve heard during fetal development.

In one recent study, Dr. Werker and her collaborators showed that babies born to bilingual mothers not only prefer both of those languages over others — but are also able to register that the two languages are different.

In addition to this ability to use rhythmic sound to discriminate between languages, Dr. Werker has studied other strategies that infants use as they grow, showing how their brains use different kinds of perception to learn languages, and also to keep them separate.

In a study of older infants shown silent videotapes of adults speaking, 4-month-olds could distinguish different languages visually by watching mouth and facial motions and responded with interest when the language changed. By 8 months, though, the monolingual infants were no longer responding to the difference in languages in these silent movies, while the bilingual infants continued to be engaged.

“For a baby who’s growing up bilingual, it’s like, ‘Hey, this is important information,’ ” Dr. Werker said.

Over the past decade, Ellen Bialystok, a distinguished research professor of psychology at York University in Toronto, has shown that bilingual children develop crucial skills in addition to their double vocabularies, learning different ways to solve logic problems or to handle multitasking, skills that are often considered part of the brain’s so-called executive function.

These higher-level cognitive abilities are localized to the frontal and prefrontal cortex in the brain. “Overwhelmingly, children who are bilingual from early on have precocious development of executive function,” Dr. Bialystok said.

Dr. Kuhl calls bilingual babies “more cognitively flexible” than monolingual infants. Her research group is examining infant brains with an even newer imaging device, magnetoencephalography, or MEG, which combines an M.R.I. scan with a recording of magnetic field changes as the brain transmits information.

Dr. Kuhl describes the device as looking like a “hair dryer from Mars,” and she hopes that it will help explore the question of why babies learn language from people, but not from screens.

Previous research by her group showed that exposing English-language infants in Seattle to someone speaking to them in Mandarin helped those babies preserve the ability to discriminate Chinese language sounds, but when the same “dose” of Mandarin was delivered by a television program or an audiotape, the babies learned nothing.

“This special mapping that babies seem to do with language happens in a social setting,” Dr. Kuhl said. “They need to be face to face, interacting with other people. The brain is turned on in a unique way.”
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References:

Klass, Perri. 2011. "Hearing Bilingual: How Babies Sort Out Language". New York Times. Posted: October 11, 2011. Available online: http://www.nytimes.com/2011/10/11/health/views/11klass.html?_r=1

Ancient cave paintings threatened by tourist plans

Prehistoric paintings in northern Spain could be irreparably damaged if plans to reopen the Altamira cave to tourists go ahead. Local officials want to reopen the cave to boost the local economy, but visitors could heat the caves and introduce microbes that destroy pigments.

The Altamira cave paintings were discovered in 1879 and are thought to be at least 14,000 years old. The paintings have attracted huge numbers of visitors – 175,000 in 1973, the busiest year on record. But the cave was closed to the public in 2002 after photosynthetic bacteria and fungi were found to be consuming pigments at alarming rates.

Plans to reopen the caves could restart the damaging processes. A team from the Spanish National Research Council in Madrid have modelled the effect of visitors over a number of years and say that tourists would increase the temperature, humidity and carbon-dioxide levels in the cave, creating conditions in which microbes would thrive.

In addition, visitors would bring with them organic matter in the form of skin flakes, clothing fibres and dust, which microbes can consume. Air turbulence created by moving people would spread bacterial and fungal spores to other, previously unaffected spaces.
Another Lascaux?

Although reopening the caves might boost the economy in the short term, says lead researcher Cesáreo Sáiz Jiménez, the damage would outweigh the benefit. "The paintings are a legacy from the past and their importance exceeds local culture."

The researchers say they want to prevent the scale of damage that occurred at the Lascaux cave in France, where mismanagement led to successive waves of pathogens attacking wall paintings there. For example, pesticides intended to destroy microorganisms became a source of nutrients for them instead.

Sáiz Jiménez and his colleagues conclude that only isolation from the outside world can prevent the same kind of damage at Altamira.
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References:

Harvey, Charles. 2011. "Ancient cave paintings threatened by tourist plans". New Scientist. Posted: October 6, 2011. Available online: http://www.newscientist.com/article/dn21020-ancient-cave-paintings-threatened-by-tourist-plans.html

Prehistoric Dog Found with Mammoth Bone in Mouth

Dog brains may have been used for ritualistic purposes by humans.

The remains of three Paleolithic dogs, including one with a mammoth bone in its mouth, have been unearthed at Předmostí in the Czech Republic, according to a new Journal of Archaeological Science paper.

The remains indicate what life was like for these prehistoric dogs in this region, and how humans viewed canines. The dogs appear to have often sunk their teeth into meaty mammoth bones. These weren’t just mammoth in size, but came from actual mammoths.

In the case of the dog found with the bone in its mouth, the researchers believe a human inserted it there after death.

"The thickness of the cortical bone shows that it is from a large mammal, like a rhinoceros, steppe bison or mammoth," lead author Mietje Germonpré told Discovery News. "At Předmostí, mammoth is the best-represented animal, with remains from more than 1,000 individuals, so it is probable that the bone fragment is from a mammoth."

Germonpré, a paleontologist at the Royal Belgian Institute of Natural Sciences, and colleagues Martina Laznickova-Galetova and Mikhail Sablin, first studied the remains, focusing on the skulls, to see what animals they might be. In the fossil record, there is sometimes controversy over what is a wolf, dog or other canid.

"These skulls show clear signs of domestication," Germonpré said, explaining they are significantly shorter than those of fossil or modern wolves, have shorter snouts, and noticeably wider brain cases and palates than wolves do.

She described them as large, with an estimated body weight of just over 77 pounds. The shoulder height was at least 24 inches.

"The shape of their skull resembles that of a Siberian husky, but they were larger and heavier than the modern husky," she said.

The dogs died when they were between 4 and 8 years old. They had numerous broken teeth during their lifetimes.

Based on what is known of the human culture at the site, the researchers believe these dogs “were useful as beasts of burden for the hauling of meat, bones and tusks from mammoth kill sites and of firewood, and to help with the transport of equipment, limiting the carrying costs of the Předmostí people.”

Since mammoth meat was likely the food staple, the scientists further believe that the surplus meat “would have been available to feed the dogs.”

The dog skulls show evidence that humans perforated them in order to remove the brain. Given that better meat was available, the researchers think it’s unlikely the brains served as food.

Instead, based on these archaeological finds and the ethnographic record, it’s possible that there was ritual importance to the actions.

"Among many northern indigenous peoples, it was believed that the head contains the spirit or soul," Germonpré explained. “Some of these peoples made a hole in the braincase of the killed animal so that the spirit might be released.”

The mammoth bone in the dog's mouth could signify "that the dog was 'fed' to accompany the soul of the dead (animal) on its journey."

Rob Losey, an associate professor of anthropology at the University of Alberta, told Discovery News that the new study is "very convincing," and shows "quite clearly that the dog domestication process was underway thousands of years earlier than previously thought."

He added, "The distinctive treatment given some of the remains also is compelling, and this indicates to me that a special connection had developed between people and some canids quite early on -- long prior to any good evidence for dogs being buried."
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References:

Viegas, Jennifer. "Prehistoric Dog Found with Mammoth Bone in Mouth". Discovery News. Posted: October 7, 2011. Available online: http://news.discovery.com/animals/paleolithic-dogs-111007.html

Humans Are Still Evolving, Study Says

Humans, like all other organisms on Earth, are subject to the pressures of evolution. New research suggests that even in relatively modern societies, humans are still changing and evolving in response to the environment.

"Whether humans could or could not evolve in modern times could have interesting implications," study researcher Emmanuel Milot, of the University of Quebec in Montreal, told LiveScience. It could help us understand changing trends for the different traits of a population.

By studying an island population in Quebec, the researchers found a genetic push toward younger age at first reproduction and larger families. This is the first direct evidence of natural selection in action in a relatively modern human population.

Past studies have hinted our species continues to evolve, with research showing changes to hundreds of genes in the human genome over the past 10,000 years; in addition, skull measurements suggest our brains have been shrinking over the last 5,000 years or so.

An island population

The study used data from 30 families who settled on île aux Coudres, located in the St. Lawrence River outside of Quebec City, between 1720 and 1773. A church on the island held historical records of all births, deaths and marriages on the island, from which researchers were able to build intensive family trees.

The researchers analyzed the data from women who married between 1799 and 1940, comparing their relations, any social, cultural or economic differences, and the age they had their first child.

The researchers found that over a 140-year period, age at first reproduction dropped from 26 to 22, with somewhere between 30 percent and 50 percent of this variation being explained by genetic variation in the population, not by other factors, such as changes in cultures or social attitudes.

"We think, traditionally, that the changes in human population are mainly cultural, which is why a non-genetic hypothesis is given priority over a genetic or evolutionary hypothesis, whether or not there is data to support that," Milot said. "We have data that we analyzed from the genetic and nongenetic point of view, and we find that the genetic factors are stronger."

Naturally selected population

Because of the populations' lack of birth control, families in this population ended up being very large, and since fertility wasn't altered by outside influences, each couple was likely to reach maximum fertility.

The researchers didn't look at which genes might have changed over time, but they suggest reasons for the age change could include differences in fertility and how early a woman hits puberty, or even heritable personality traits that would nudge a woman to procreate earlier. These genetic factors would be changing in response to the natural selection for a higher number of kids overall.

"In that particular population, selective pressure seemed pretty constant for the study period," Milot said. "Maybe it has to do because it has a newly founded population and it was not disadvantageous to have big families."

A newly founded population would have the resources to support large families, and more kids mean the higher likelihood that one's genes would survive well into the future.

Evolving humans

Seeing natural selection in modern populations is incredibly difficult. Because this population was pretty highly related and relatively cut off from outside populations, the correlation between genetic factors and age at first reproduction was easier to see.

"What we learn from that population is that evolution is possible in relatively modern times in modern humans," Milot said. "Where it is going to occur and in what ways is a different question."

Steve Stearns, a researcher from Yale University who wasn't involved in the study, told LiveScience in an email that the work "is an important advance, because it demonstrates a genetic response to selection in a recent, almost a contemporary, human population."
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References:

Welsh, Jennifer. 2011. "Humans Are Still Evolving, Study Says". Live Science. Posted: Available online: http://www.livescience.com/16358-human-evolution-natural-selection.html

How continents shaped human culture

How modern-day humans dispersed on the planet and the pace of civilization-changing technologies that accompanied their migrations are enduring mysteries. Scholars believe ancient peoples on Europe and Asia moved primarily along east-west routes, taking advantage of the relative sameness in climate, allowing technological advances to spread quickly.

But what about in North and South America, with its long, north-south orientation and great variability in climate? How did people move and how quickly did societal innovations follow?

Studying the human genome

Using advanced genetic analysis techniques, evolutionary biologists at Brown University and Stanford University studied nearly 700 locations on human genomes drawn from more than five dozen populations. They say that technology spread more slowly in the Americas than in Eurasia and that the continents’ orientation seems to explain the difference. After humans arrived in the Americas 20,000 to 40,000 years ago, genetic data shows, the migrating populations didn’t interact as frequently as groups in Eurasia.

“If a lack of gene flow between populations is an indication of little cultural interaction,” the authors write in the American Journal of Physical Anthropology, “then a lower latitudinal rate of gene flow suggested for North American populations may partly explain the relatively slower diffusion of crops and technologies through the Americas when compared with the corresponding diffusion in Eurasia.”

“Our understanding of the peopling of the Americas will be refined by archaeological data and additional genetic samples,” added Sohini Ramachandran, assistant professor of biology in the Department of Ecology and Evolutionary Biology at Brown and the paper’s lead author. “But this is the signature of migration we see from genetic data.”

To tease out the migration patterns, Ramachandran and fellow researcher Noah Rosenberg from Stanford gathered genetic markers for 68 indigenous populations from 678 genetic markers in Eurasia and the Americas. The goal was to study the distribution of genetic variation among populations. The similarity or difference in genetic make-up among populations gave the scientists insights about migrations long ago.

To illustrate, when one population breaks off from its parent group, the individuals in the new population take their genomes and any distinct genetic mutations with them. From there, the new population may remain independent of the parent group because of distance or other factors, and over time its genetic make-up diverges from the parent. However, if the new population reunites regularly with its parent population — known as “back migration” — the genetic make-up of the two populations remains relatively close.

“When populations do not share migrants with each other very often,” Rosenberg explained, “their patterns of genetic variation diverge.”

Testing the spread of innovation

Armed with the genetic background of cultures spanning the Americas and Eurasia, the researchers could test whether the east-west orientation of Eurasia supported a rapid spread of agriculture and other societal innovations, while the dissemination of those advances was slower in the Americas due to the north-south orientation. They found that to be the case: The populations in North and South America are, for the most part, more different from each other than the populations in Eurasia. The reason has to do with the differing climates that migrating peoples in the Americas found when they moved north to south.

“It’s harder to traverse those distances based on climate than it was in Eurasia,” Ramachandran said. “We find greater genetic differences (in the Americas’ populations) because of the difficulty in migration and the increased challenge of reuniting with neighbouring populations.”

“Our result that genetic differentiation increases more with latitudinal distance between Native American populations than with longitudinal distance between Eurasian populations supports the hypothesis of a primary influence for continental axes of orientation on the diffusion of technology in Eurasia and the Americas,” the authors conclude.
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References:

Past Horizons. 2011. "How continents shaped human culture". Past Horizons. Posted: October 3, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/10/2011/how-continents-shaped-human-culture

Cannibalism Confirmed Among Ancient Mexican Group

Eating humans "crucial" to spiritual life of the Xiximes people.

It's long been rumored that an ancient, isolated people in what's now northern Mexico ate their own kind, in the hopes that they'd be able to eat corn later.

Now an analysis of more than three dozen bones bearing evidence of boiling and defleshing confirms that the Xiximes people were in fact cannibals, archaeologists say.

The Xiximes believed that ingesting the bodies and souls of their enemies and using the cleaned bones in rituals would guarantee the fertility of the grain harvest, according to historical accounts by Jesuit missionaries.

The newfound bones prove that cannibalism, "was a crucial aspect of their worldview, their identity," said José Luis Punzo, an archaeologist behind the new research.

Eating Only Their Own

The mountains of what's now Durango state (map) were once home to some 5,000 Xiximes, as well as other indigenous groups.

It was only the Xiximes and the like-minded Acaxées who are said to have been cannibals, though no archaeological evidence for the practice has been found for the Acaxées, said Punzo, of the Durango office of the Mexican National Institute of Anthropology and History (INAH).

"Through their rituals, cannibalism, and bone hoarding, they marked a clear boundary between an 'us' and 'them,'" Punzo said—"us" being the Acaxées and Xiximes, and "them" being everybody else.

The two groups fought and killed members of other groups, he said. But the Acaxées and Xiximes ate only their own kind, specifically men. Other native groups and Spanish colonizers were apparently ritually worthless, according to historical studies.

Cave Cache of Boiled Bones

Some historians had derided the missionaries' reports of cannibalism as exaggerations. But the bones found in Cueva del Maguey—a hamlet built inside a huge, cliffside cave—should erase any doubts, Punzo said.

Tests showed that 80 percent of four dozen bones—found in houses dated to around 1425—bear marks and other evidence of being boiled and cut with blades of stone, Punzo added.

The bones had been relatively untouched for centuries—a godsend for scientists made possible by the isolation of Cueva del Maguey, deep in a pine forest and 8,530 feet (2,600 meters) above sea level.

Circle of Life

For the Xiximes, the planting-and-sowing cycle was intertwined with a cycle of cannibalism and bone rituals, according to the INAH report, announced at the 14th Archaeology Conference of the North Frontier this summer in Paquimé, Mexico.

After each corn harvest, Xiximes warriors were deployed to hunt for enemies—and their flesh.

Most of the time the Xiximes would prey on lone men from other villages working in the fields. Other times, the Xiximes would engage small groups in forest battles, according to the historical record.

The warriors would bring the dead victims back to the village, where Xiximes would rip the bodies apart at the joints, taking care not to break the bones. In cases when carrying a whole body was impractical, the head and hands would be removed and brought back to the village, according to INAH's research.

Body parts were cooked in pans until the bones emerged clean. The flesh was then cooked with beans and corn and eaten in a type of soup—part of an all-night village ritual, complete with singing and dancing, according to missionaries' reports.

After the feast, the bones were stored for months in treasure houses. Then, in the run-up to the annual planting season, the Xiximes would hang the bones from roofs and trees—enticements to the spirits to help the crops along.

"For these practices," Punzo said, "they were called by Jesuits the wildest and most barbarian people of the New World."
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References:

Valle, Sabrina. 2011. "Cannibalism Confirmed Among Ancient Mexican Group". National Geographic News. Posted: September 30, 2011. Available online: http://news.nationalgeographic.com/news/news/2011/11/110930-cannibalism-cannibals-mexico-xiximes-human-bones-science/

Culture Poisons Brain With Racism, Study Finds

For years, social scientists have uncovered the unsettling truth that no matter how egalitarian a person purports to be, their unconscious mind holds some racist, sexist or ageist thoughts.

But a new study finds that this may say less about the person and more about the culture that surrounds him or her.

The new study finds that while people are quick to associate word pairs that bring to mind stereotypes (think "black - poor" versus "black - goofy"), this tendency is rooted not in the social meaning of the words, but in the likelihood of the words appearing together in literature and media. In other words, this implicit prejudice is driven more by culture than by any innate horribleness in the person, said study researcher Paul Verhaeghen, a Georgia Tech psychologist.

"There’s one idea that people tend to associate black people with violence, women with weakness, or older people with forgetfulness because they are prejudiced. But there’s another possibility that what’s in your head is not you, it’s the culture around you," Verhaeghen said in a statement. "And so what you have is stuff you picked up from reading, television, radio and the Internet. And that’s the question we wanted to answer: are you indeed a racist, or are you just an American?"

Responding to prejudice

In study after study, people more quickly associate word pairs that bring to mind stereotypes. "Female" and "weak" would be more quickly associated than "female" and "mundane," for example. This implicit prejudice is different than explicit prejudices, which psychologists measure by asking people questions about how they feel about various social groups.

But the root of implicit prejudice wasn't clear. People might associate the word pairs because they saw shared meaning in them — they really do think of "black" and "poor" as overlapping terms. But people also might link the two words because they simply see the words "black" and "poor" together in literature and media more often than the words "black" and "goofy."

Verhaeghen and his colleagues tested the second theory by giving 104 undergraduates one of three tests. In the first, the student saw two words flashed on a computer screen one after another, and then had to say whether the second word was a real word. In the second, the words would flash onscreen, and the participant would rate whether the second word was positive or negative. The third experiment was identical, except students were asked whether the two words were related.

The word pairs were a mixture of stereotyped terms about men, women, blacks, whites and young and old people. There were also non-social word pairs such as "cat - jumpy" and "dog - dumb." Some of the pairs included nonsense words as well.

Word association

In all three experiments, a faster reaction time in answering the question indicates a closer link between the two words in the brain. Like in other studies, participants were faster at reacting to word pairs that elicited stereotypes. [Read: 5 Myths About Gay People, Debunked]

But this experiment had another layer: The researchers analyzed the results using a computer program called BEAGLE, or the Bound Encoding of the Aggregate Language Environment. This program contains a sample of books, magazine and newspaper articles, about 10 million words total. It's meant to mimic the amount of reading an average college student has done in his or her life.

The program analyses all the words in the reading sample, including how often two words appear near one another. If culture plays into implicit stereotyping, closely related words should always result in fast reaction times, regardless of the social meaning of those words.

The racist inside

Comparing their participants' results to BEAGLE confirmed that, indeed, words that appear more often together in the real world trigger faster reaction times in the lab. This applies for positive and negative stereotypes, such as "male - strong" and "female - weak" and for completely neutral pairs such as "summer - sunny."

There was also no relationship between people's implicit prejudices as measured by reaction time, and their explicit racism, sexism or ageism as measured by questionnaires.

"This suggests that at least part of the alleged racist/sexist/ageist hiding inside us all is a monster not of our own making; it is built out of memes borrowed from close contact with our environment," Verhaeghen and his colleagues reported online Sept. 17 in the British Journal of Social Psychology.

Although limited by the college-age population, the researchers argue that the results paint a picture of prejudice as a painful cycle: Prejudiced thought begetting prejudiced speech, which is then internalized to begat even more prejudiced thought.

But "culture made me do it" is no excuse for racism, they add, writing, "society's influence on its individual constituents does not absolve these individuals from their own personal responsibilities." In fact, Verhaeghen said, the study suggests the need for extra caution.

"There's a reason for political correctness," he said. "At least, as studies suggest, it might be a good idea to not put stereotypes out there too clearly, because if you do, people will internalize them."
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References:

Pappas, Stephanie. 2011. "Culture Poisons Brain With Racism, Study Finds". Live Science.. Posted: October 2, 2011. Available online: http://www.livescience.com/16339-culture-racism.html

Pre-Incan human sacrifices unearthed in Peru

See the video here

Peruvian archaeologists have found evidence that a pre-Incan civilization, the Chimu of northern Peru, practised human and animal sacrifices.

The remains of 40 children and 74 llamas, sacrificed around 800 years ago, were found in the village of Huanchaquito.

The discovery also suggests possible links to other ancient civilisations in the region like the Aztecs, the archaeologists say.
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References:

BBC News. 2011. "Pre-Incan human sacrifices unearthed in Peru". BBC News. Posted: September 28, 2011. Available online: http://www.bbc.co.uk/news/world-latin-america-15093144

Climate Change Takes a Toll on Cultures

There are nearly 7,000 known languages in the world today. It is predicted that half of these, in many cases vessels of indigenous cultures, will vanish over the next 50 years.

This has been much on the mind of Brigitte Baptiste, who took over this year as director of the Colombian Environment Ministry’s Alexander von Humboldt Biological Resources Research Institute. Although rigorous assessments of indigenous vulnerability have been few and far between, she says, climate change is known to cause shifts in the growth of flora and fauna in local ecosystems, from animal migrations to natural cycles like pollination.

In some places, the shifts in ecosystems require indigenous cultures to rapidly adapt or perish as their traditional means of subsistence becomes harder to sustain.

For example, the Wayuu, who have lived for centuries in Colombia’s arid northwest, depend on the glacially fed Rancheria River as well as two rainy seasons to support a culture rich in fishing and animal husbandry. But glacial retreat means that the river is often at lower levels than it used to be, and seasonal weather is becoming both less predictable and more violent.

Over longer arcs of time, Dr. Baptiste explained by e-mail, indigenous knowledge keeps pace with change, assuring the viability of the community. But in the case of rapid climate change, “if this adaptive capacity, already embedded in the fabric of local cultures, fails to give quick answers, the youngest members of the community may jump out of the tradition.”

Many indigenous youths are already resettling in urban areas because of tribal displacement and the allure of rising economies, a phenomenon exemplified by the Nukak-Makú people of Colombia. Climate change will only compound the problem, Dr. Baptiste said.

She raised this concern in August at Colombia’s Second National Climate Congress.

At first glance, the loss of cultural diversity may seem insignificant in comparison with climate changes like sea-level rise, ocean acidification and mass extinctions of plants or animals. But just as biophysical diversity improves the resilience of natural systems and acts as buffer against adverse conditions, cultural diversity offers a resilient knowledge base for adapting to and counteracting the effects of climate change.

The little-known Kauai Declaration, a two-page document signed by 41 of the world’s preeminent ethnobotanists, states that every culture “represents a distinct philosophical and pragmatic” approach to nature. Each cultural loss therefore diminishes understanding of the world and therefore adaptive capacity, it suggests.

Yet cultural knowledge can in some cases be rediscovered. In the dry and salty high planes of southern Peru, for example, an agricultural technology from 300 B.C., once lost, has again taken root because of its local suitability. The waru waru are a patterned series of earthen berms, raised beds and interstitial canals that make salty soils productive and protect against flooding, drought and frost.

The technology disappeared after the decline of the Tiahuanaco culture around A.D. 1100. Archaeologists rediscovered the system in the 1980s, and a formal waru waru restoration project took root in 1991.

Since its recovery, this traditional technology has become a valuable and widespread agricultural safeguard against increasingly common climatic extremes.

Nascent efforts toward fortifying and preserving indigenous cultures are gaining traction on most continents. In Africa, the Indigenous Peoples of Africa Coordinating Committee helps a network of 150 indigenous groups devise local and regional responses to climate change.

In Europe, the Institute of Development Studies is establishing an Indigenous Knowledge and Climate Change Research Network that aims to “look in greater depth at the learning, exchange and valuing of indigenous knowledge on climate change,” according to Blane Harvey, one of the project’s three directors.

North American scientists are collaborating with Inuit leaders to gain an understanding of changes in the Arctic and the potential impacts on native livelihoods.

In Colombia, Dr. Baptiste said that the Humboldt Institute recently introduced a national initiative to include all of the indigenous groups who own common lands in a broader debate about biodiversity management. Indigenous groups hold at least half of the country’s remaining wild forest.

Nonetheless, Dr. Baptiste cautions that at least in Colombia, most discussion surrounding the preservation and dissemination of indigenous culture remains little more than political oratory divorced from concrete action.
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References:

Walsh, Dylan. 2011. "Climate Change Takes a Toll on Cultures". New York Times. Posted: September 27, 2011. Available online: http://green.blogs.nytimes.com/2011/09/27/climate-change-takes-a-toll-on-cultures/

Translators of a faraway time

Norway’s rugged coast has perhaps no better analogue than the glacially scoured shoreline of Patagonia, 13,000 kilometres away and a hemisphere apart. The two countries’ similarities, isolated from each other, make them perfect natural laboratories for archaeologists interested in how early man lived in and adapted to marine environments.

Archaeologists from the two countries involved in a cooperative project called “Marine Ventures” met in Norway this summer in search of clues to the past.

Worlds apart – but almost the same

“Our project, Marine Ventures, gives us a valued opportunity to explore similarities and differences in both landscapes and marine pioneers between the two countries,” says Professor Hein Bjerck, from the Norwegian University of Science and Technology’s (NTNU) Museum of Natural History and Archaeology in Trondheim.

His Argentinean colleague, Lic. Ernesto Piana from Centro Austral de Investigaciones Cientificies – CONICET in Ushiaia, Tierra del Fuego, says that the two research groups can build on each other’s strengths. “As archaeologists, we are translators of what people did in the past,” he says. “Now, in bringing our knowledge together, we can be better translators. We in Argentina have more experience with organic material, while here in Norway there’s a greater understanding of landscapes. ”

Locations in Norway, organic material in Patagonia

Bjerck notes that the coasts of the two countries are extremely similar because of their history of glaciation during the Pleistocene. In this region, early man had to be dedicated to the sea. Despite the similarities between the two countries, however, they have very different physical characteristics, which affects archaeological remains.

“The main difference is that we have 1000 known localities in Norway from the early Mesolithic era (9500-8000 BC), but we don’t have any organic material,” Bjerck says. “In Patagonia, however, they have few very early locations, but much more information on the sites: tools, organic material, and food remains, like seal and mussels.”

“We’re looking at 30 years of research on the Mesolithic period. Putting it all together, both the Norwegian and the Argentinean, gives us a broader perspective on the dynamics of early marine adaptations,” Piana says.

Coastal landscapes

The glacial erosion of Patagonia and Scandinavia produced a characteristic coastal landscape with abundant skerries, islands, channels and fiords. This seascape constitutes highly productive marine habitats – and sheltered seas that are optimal for maritime foragers. “Tierra del Fuego is like a slightly sanded down version of Norway,” says Piana.

Scientific advantages

Patagonia and Northern Norway are situated on different continents – thus excluding all kinds of cultural contacts prior to the European visitors during the Historical periods.

“This is one of the obvious scientific advantages that allows us to study how human beings have adapted to their environmental, material and social surroundings in two different, yet similar settings,” the researchers say.

They note that the Norwegian record on adaptation to marine environments is solely archaeological, but this type of livelihood lasted in Patagonia until the European colonization of the region. As such, there is written source material about how local people lived in these marine environments, as well as in their collective memory and identities.
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References:

Past Horizons. 2011. "Translators of a faraway time". Past Horizons. Posted: September 27, 2011. Available online: http://www.pasthorizonspr.com/index.php/archives/09/2011/translators-of-a-far-away-time

Ancient ways and modern times

The Kumeyaay people practice their traditions and revive native crafts in remote areas of Mexico and California as encroaching civilization brings electricity and running water.

In the high table land, a small, rawboned woman picks her way across ash and sand to a cave where she slept as a girl when her family came to harvest pine nuts every August.

Teodora Cuero is 90 years old, half-blind behind her sunglasses, with skin like crinkled wax paper.

She moves her fingers over the lichen-mottled rock, and the memories flood her with emotion. She talks of lost friends and family members, how they used to live.

Her friend Mike Wilken, an anthropologist, listens with rapt attention. What she describes are final scenes from the Indians' ancient yearly migration between the sea and desert, a pattern of life in Southern California and northern Baja long before the Spanish set foot here.

The territory of Cuero's people, the Kumeyaay, extended along the coast from what is today Carlsbad in the north, to the Santo Tomas Valley in Baja in the south, and over the mountains to the desert. The international boundary that was drawn across that terrain would put the tribe on separate trajectories. So unlike the many native peoples of Southern California whose language and customs were extinguished, hers found a measure of refuge in the remote, dusty valleys just south of the border.

Ancient ways remained not only relevant but necessary to get by in areas that had few staples from the modern world. They endure in many forms today.

No one embodies this more than Cuero, who didn't have shoes and spoke only Kumeyaay until she was a teenager, living 80 miles from downtown San Diego.

Today she lives in a rock house for which her husband traded a horse, speaks mostly Kumeyaay, cooks on an antique wood-burning stove in the garden, uses plant remedies for ailments and relies on food she gathers from the land to supplement her rice and beans. Goats andhorses roam the dirt roads of her village, La Huerta, which got electricity seven years ago.

Her life is not a simple snapshot of the past, but a complex amalgam of old and new. Cuero has a cellphone and refrigerator. She naps on a bench seat extracted from a recently deceased Ford pickup. She drinks inky black coffee and smokes Marlboros.

Over the last three years, Wilken has worked with Kumeyaay elders like Cuero to document their language and those traditions they adapted to the times. His material goes to a National Science Foundation project on documenting endangered languages and a museum in Tecate he helped establish.

"There are certain stories people want to hear about the Indians," Wilken said. "That they are living a way of life that hasn't changed in thousands of years. They want to know about shamans and go to a sweat lodge. We have to get over some pre-formed idea of who they are and experience them as they are."

He began working with the Kumeyaay 15 years ago as an "applied" anthropologist, meaning he not only studied them but worked with them to make endangered traditions more useful to them. He helped find markets for their basketry and native medicines, and arranged cultural exchanges with the Kumeyaay in the United States, who wanted to learn more about their heritage.

"When people from the California communities meet Kumeyaay from Baja they say, 'This is how we lived 50 or 100 years ago,' " Wilken said.

::

The Kumeyaay greeted the first Spanish expedition in California in 1769. They had been here for at least 1,300 years, anthropologists say, maybe many thousands more. The Kumeyaay lived in temporary brush huts and moved throughout the year in search of food.

While many ended up in the Spanish missions and later on reservations, many others did not.

Into the early 20th century, clans of outliers still roamed the margins of the expanding Yankee society, following their old trails, speaking little English or Spanish and crossing the border without even knowing there was one.

Their exile was searingly documented in the autobiography of Delfina Cuero, who was born near Jamul in 1900 and told her story to an anthropologist in the 1960s.

As a child, Delfina, a cousin of Teodora Cuero's father, followed her parents around San Diego County, looking for ranch work while hunting and foraging. They collected shellfish and crabs on the rocks of Point Loma. They speared fish in the coastal waters and harvested greens and roots from the black mud of what is now called Mission Bay.

In spring, they went to the desert for agave stalks, which they roasted in pits for food. In summer, they moved to the mountains to collect pine nuts, then down into the valleys for acorns in fall.

When her father had ranch work, they would build a brush hut in a nearby arroyo. But as more and more ranches were cleared, ranchers told them to go away. They lost access to the coast, then Mission Valley, then the foothills. Their migration routes were cut off.
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References:

Mozingo, Joe. 2011. "Ancient ways and modern times". Los Angeles Times. Posted: September 26, 2011. Available online: http://articles.latimes.com/2011/sep/26/local/la-me-adv-kumeyaay-20110927

First Aboriginal genome sequenced

1920s hair sample reveals Aboriginal Australians' explorer origins.

A 90-year-old tuft of hair has yielded the first complete genome of an Aboriginal Australian, a young man who lived in southwest Australia.

He, and perhaps all Aboriginal Australians, the genome indicates, descend from the first humans to venture far beyond Africa more than 60,000 years ago, and thousands of years before the ancestors of most modern Asians trekked east in a second migration out of Africa.

"Aboriginal Australians are descendents of the first human explorers. These are the guys who expanded to unknown territory into an unknown world, eventually reaching Australia," says Eske Willerslev, a palaeogeneticist at the University of Copenhagen, Denmark, who led the study. It appears online today in Science¹.

Hanging on a hair

The oldest human remains in Australia date to around 50,000 years ago², and yet older stone tools found in India and elsewhere hint at an early southern migration of anatomically modern humans out of Africa and through India and Southeast Asia.

However, genetic studies of contemporary Asians and Oceanians haven't always told the same story. The most comprehensive genetic analysis carried out so far pointed to a single migration that spawned all Asian populations, including Aboriginal Australians³. But estimated times of the separation of European and Asian ancestors in this population does not chime well with the archaeological evidence for the continuous settlement of Australia from much earlier times.

A complete genome from an Aboriginal Australian would settle this debate, Willerslev says. Many contemporary Aboriginal Australians also descend from Europeans because of recent interbreeding between Aboriginals and Australian colonists. To get a better picture of the ancient history of Aboriginals, Willerslev wanted to sequence the genome of someone who did not descend from Europeans.

About a year ago, his team obtained a hair sample originally collected by the British ethnologist Alfred Cort Haddon. Historical records suggest that Haddon got the hair from a young Aboriginal man in the early 1920s while on a train journey from Sydney to Perth.

Willerslev believes that the man offered his hair to Haddon willingly, and a Danish bioethics review board saw no problem with sequencing his genome. Willerslev later received the blessing of a committee that represents Aboriginal people in the region where the man probably lived.

An analysis of his genome indicates that his ancestors started their journey more than 60,000 years ago, branching off from humans who left Africa. The ancestors of contemporary Europeans and most other Asians probably went their separate ways less than 40,000 years ago, according to Willerslev's team.

Ancient relations

Like other populations outside Africa, the Australian Aboriginal man owes small chunks of his genome to Neanderthals⁴. More surprisingly, though, his ancestors also interbred with another archaic human population known as the Denisovans. This group was identified from 30,000–50,000-year-old DNA recovered from a finger bone found in a Siberian cave⁵. Until now, Papua New Guineans were the only modern human population whose ancestors were known to have interbred with Denisovans.

A second study incorporating genomic surveys from different Aboriginal Australians paints an even clearer picture of their ancestors' exploits with the Denisovans. Researchers led by Mark Stoneking at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, calculated the portion of Denisovan ancestry found in the genomes of 243 people representing 33 Asian and Oceanian populations. Patterns of Denisovan interbreeding in human populations could reveal human migration routes through Asia, reasoned the team. The paper is published today in the American Journal of Human Genetics⁶.

This comparison revealed a patchwork in which some populations, including Australian Aboriginals, bore varying levels of Denisovan DNA, while many of their neighbours, like the residents of mainland Southeast Asia, contained none.

Stoneking says that this pattern hints at at least two waves of human migration into Asia: an early trek that included the ancestors of contemporary Aboriginal Australians, New Guineans and some other Oceanians, followed by a second wave that gave rise to the present residents of mainland Asia. Some members of the first wave (though not all of them) interbred with Denisovans. However, the Denisovans may have vanished by the time the second Asian migrants arrived. This also suggests that the Denisovan's range, so far linked only to a cave in southern Siberia, once extended to Southeast Asia and perhaps Oceania.

"Put together, these two papers make an overwhelming case for multiple waves of migration," says David Reich, a population geneticist at Harvard Medical School in Boston, an author on the second study.

Alan Redd, a biological anthropologist at the University of Kansas in Lawrence, says that the peopling of Australia may have been more complicated than either paper suggests. Dingoes, for instance, were brought to the island continent by humans who arrived in the last 5,000 years. "It's certainly possible that people were trickling in at different times," he says.
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References:

Callaway, Ewen. 2011. "First Aboriginal genome sequenced". Nature. Posted: September 22, 2011. Available online: http://www.nature.com/news/2011/110922/full/news.2011.551.html

Article References:

1. Rasmussen, M. et al. Science http://10.1126/science.1211177 (2011).
2. Bowler, J. et al. Nature 421, 837-840 (2003).
3. HUGO Pan-Asian SNP Consortium Science 326, 1541-1545 (2009).
4. Green, R. E. et al. Science 328, 710-722 (2010).
5. Reich, D. et al. Nature 468, 1053-1060 (2010).
6. Reich, D. et al. Am. J. Hum. Genet. 89, 1-13 (2011).