Wednesday, April 23, 2014

New insights into ancient Pacific settlers' diet: Diet based on foraging, not horticulture

Researchers from New Zealand's University of Otago studying 3000-year-old skeletons from the oldest known cemetery in the Pacific Islands are casting new light on the diet and lives of the enigmatic Lapita people, the likely ancestors of Polynesians.

Their results -- obtained from analysing stable isotope ratios of three elements in the bone collagen of 49 adults buried at the Teouma archaeological site on Vanuatu's Efate Island -- suggest that its early Lapita settlers ate reef fish, marine turtles, fruit bats, free-range pigs and chickens, rather than primarily relying on growing crops for human food and animal fodder.

The findings are newly published in the journal PLOS ONE. Study lead author Dr Rebecca Kinaston and colleague Associate Professor Hallie Buckley at the Department of Anatomy carried out the research in collaboration with the Vanuatu National Museum and researchers from the University of Marseilles and CNRS (UMR 7269 and UMR 7041) in France and The Australian National University, Canberra.

Dr Kinaston says the study is the most detailed analysis of Lapita diet ever undertaken and provides intriguing insights into the socio-cultural elements of their society.

"It was a unique opportunity to assess the lifeways of a colonising population on a tropical Pacific island," she says.

The researchers analysed the isotopic ratios of carbon, nitrogen and sulphur in adult human bone collagen and compared these with ratios in ancient and modern plants and animals from the location, which provided a comprehensive dietary baseline.

"Examining these ratios gave us direct evidence of the broad make-up of these adults' diets over the 10-20 years before they died, which helps clear up the long-running debate about how the Lapita settlers sustained themselves during the early phases of colonising each island during their eastward drive across the Pacific."

Dr Kinaston says it appears that the new colonists, rather than relying mainly on a "transported landscape" of the crop plants and domesticated animals they brought with them, were practicing a mixed subsistence strategy.

"The dietary pattern we found suggests that in addition to eating pigs and chickens, settlers were also foraging for a variety of marine food and consuming wild animals -- especially fruit bats -- and that whatever horticultural food they produced was not heavily relied on," she says.

Isotopic analysis of the ancient pig bones found at the site also suggests that they were free-ranging rather than penned and given fodder from harvested crops.

Study of the human bones revealed a sex difference in diet compositions, showing that Lapita men had more varied diets and greater access to protein from sources such as tortoises, pigs and chicken than women did.

"This may have resulted from unequal food distribution, suggesting that males may have been considered of higher status in Lapita society and treated preferentially," Dr Kinaston says.
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References:

Science Daily. 2014. “New insights into ancient Pacific settlers' diet: Diet based on foraging, not horticulture”. Science Daily. Posted: March 5, 2014. Available online: http://www.sciencedaily.com/releases/2014/03/140305191521.htm

Tuesday, April 22, 2014

New Texts Found in 'Dead Sea Scroll' Caves

An archaeologist says he discovered nine tiny scrolls with biblical text from the Qumran caves where the Dead Sea Scrolls were unearthed, according to news reports.

The newfound scrolls, which date back to about 2,000 years ago, were hidden inside three leather tefillin cases, also known as phylacteries, traditionally carried by observant Jewish men, Italian news agency Ansa Mediterranean reported. These cases were first pulled out of the caves in the 1950s, but their contents apparently were not examined until now.

Starting in the 1940s, the remains of more than 900 manuscripts were found in 11 caves near the site of Qumran in the West Bank. This collection Hebrew Bible texts, which came to be known as the Dead Sea Scrolls, included copies of Genesis, Exodus, Isaiah, Kings and Deuteronomy.

"'It's not every day that you get the chance to discover new manuscripts," archaeologist Yonatan Adler told Ansa Mediterranean. "It's very exciting."

The nine new documents have not been fully examined yet and it's not yet clear what's written in the text. Adler announced his findings at an international conference on Qumran and the Dead Sea Region at Lugano, Switzerland.
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References:

Gannon, Megan. 2014. “New Texts Found in 'Dead Sea Scroll' Caves”. Live Science. Posted: March 3, 2014. Available online: http://www.livescience.com/43798-new-texts-dead-sea-scroll-caves.html

Monday, April 21, 2014

Native American city on the Mississippi was America's first 'melting pot'

New evidence establishes for the first time that Cahokia, a sprawling, pre-Columbian city situated at the confluence of the Missouri and Mississippi rivers, hosted a sizable population of immigrants.

Cahokia was an early experiment in urban life, said Thomas Emerson, who led the new analysis. Emerson is Illinois state archaeologist and the director of the Illinois State Archaeological Survey at the University of Illinois.

Researchers have traditionally thought of Cahokia as a relatively homogeneous and stable population drawn from the immediate area, he said. "But increasingly archaeologists are realizing that Cahokia at AD 1100 was very likely an urban center with as many as 20,000 inhabitants," he said. "Such early centers around the world grow by immigration, not by birthrate."

The new analysis, reported in the Journal of Archaeological Research, tested the chemical composition of 133 teeth from 87 people buried at Cahokia during its heyday. The researchers looked specifically at strontium isotope ratios in the teeth and in the remains of small mammals from the same area.

"Strontium isotope ratios in rock, soil, groundwater and vegetation vary according to the underlying geology of a region," the researchers wrote. "As an animal eats and drinks, the local strontium isotope composition of the water, plants and animals consumed is recorded in its skeletal tissues." Strontium signatures may not be unique to a location, Emerson said, but the ratios in a person's teeth can be compared to those of plants and animals in the immediate environment.

"Teeth retain the isotopic signature of an individual's diet at various periods of life depending on the tooth type sampled, ranging from in utero to approximately 16 years of age," the researchers wrote. The strontium signature in the teeth can be compared to that of their place of burial, to determine whether the person lived only in that vicinity. Early teeth and later teeth may have different strontium signatures, an indication that the person immigrated.

By analyzing the teeth of those buried in different locations in Cahokia, Emerson, state archaeological survey bioarchaeologist Kristin Hedman and graduate student Philip Slater discovered that immigrants formed one-third of the population of the city throughout its history (from about AD 1050 through the early 1300s).

"This indicates that Cahokia as a political, social and religious center was extremely fluid and dynamic, with a constantly fluctuating composition," Emerson said.

The findings contradict traditional anthropological models of Cahokian society that are built on analogies with 19th-century Native American groups, Emerson said.

"Cahokia, because it was multiethnic and perhaps even multilingual, must have been a virtual 'melting pot' that fostered new ways of living, new political and social patterns and perhaps even new religious beliefs," he said.
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References:

EurekAlert. 2014. “Native American city on the Mississippi was America's first 'melting pot'”. EurekAlert. Posted: March 3, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-03/uoia-nac030314.php

Sunday, April 20, 2014

You're more biased than you think – even when you know you're biased

When it comes to the important issues, I’m pretty sure my opinions are just right. Of course I am: if I thought they were wrong, I’d trade them in for some different ones. But in reality, there’s plenty of evidence to suggest that we’re all at least somewhat subject to bias – that my support for stricter gun control laws here in the US, for example, is partly based on wanting to support my team. Tell Republicans that some imaginary policy is a Republican one, as the psychologist Geoffrey Cohen did in 2003, and they’re much more likely to support it, even if it runs counter to Republican values. But ask them why they support it, and they’ll deny that party affiliation played a role. (Cohen found something similar for Democrats. Maybe I mentioned Republicans more prominently because I’m biased?)

Surely, though, if you tell people you’re giving them biased information – if you specifically draw their attention to the risk of being led astray by bias – they’ll begin to question their own objectivity? Nope: even then, they’ll insist they’re reaching an unbiased conclusion, if a new paper by five Princeton researchers (which I found via Tom Jacobs at Pacific Standard) is anything to go by.

Emily Pronin and her colleagues asked Princeton students, and other people recruited online, to look at 80 paintings, and to give each a score from 1 to 10 based on their artistic merit. Half of the subjects weren’t told the artists’ identities. The other half were allowed to see a name, purportedly that of the painter of each picture. In fact, those names were a mixture of famous artists and names pulled from the phone book. As you’d predict, those who saw the names were biased in favour of famous artists. But even though they acknowledged the risk of bias, when asked to assess their own objectivity, they didn’t view their judgments as any more biased as a result.

Even when the risk of bias was explicitly pointed out to them, people remained confident that they weren’t susceptible to it; indeed, they actually rated their performance as more objective than they’d predicted it would be at the start of the test. “Even when people acknowledge that what they are about to do is biased,” the researchers write, “they still are inclined to see their resulting decisions as objective.”

This is more evidence for the “bias blind spot”, a term coined by Pronin which refers to the head-spinning fact that we have a cognitive bias to the effect that we’re uniquely immune to cognitive biases. Take the famous better-than-average effect, or Lake Wobegon effect, whereby the majority of people think they’re above average on any number of measures – their driving skills, their popularity, the quality of their relationship – when clearly they can’t all be right. It turns out the bias also applies to bias. In other words, we’re convinced that we’re better than most at not falling victim to bias. We seem to imagine we’re transparent to ourselves: that when we turn our attention within, we can clearly see all the factors influencing our decisions. The study participants “used a strategy that they thought was biased,” the researchers note, “and thus they probably expected to feel some bias when using it. The absence of that feeling may have made them more confident in their objectivity.”

This helps explain, for example, why it’s often better for companies to hire people, or colleges to admit students, using objective checklists, rather than interviews that rely on gut feelings. As Jacobs notes, it’s also why some orchestras ask musicians to audition from behind screens, so that only their music can be judged. It’s no good relying on the judges’ sincere confidence that they’d never let sexism or other biases get in the way. They may really believe it – but they’re probably wrong. Bias spares nobody. Except me, of course.
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References:

Burkeman, Oliver. 2014. “You're more biased than you think – even when you know you're biased”. The Guardian. Posted: February 28, 2014. Available online: http://www.theguardian.com/news/oliver-burkeman-s-blog/2014/feb/28/bias-political-psychology-burkeman-blog

Saturday, April 19, 2014

Talking Neanderthals challenge the origins of speech

We humans like to think of ourselves as unique for many reasons, not least of which being our ability to communicate with words. But ground-breaking research by an expert from the University of New England shows that our 'misunderstood cousins,' the Neanderthals, may well have spoken in languages not dissimilar to the ones we use today.

Pinpointing the origin and evolution of speech and human language is one of the longest running and most hotly debated topics in the scientific world. It has long been believed that other beings, including the Neanderthals with whom our ancestors shared Earth for thousands of years, simply lacked the necessary cognitive capacity and vocal hardware for speech.

Associate Professor Stephen Wroe, a zoologist and palaeontologist from UNE, along with an international team of scientists and the use of 3D x-ray imaging technology, made the revolutionary discovery challenging this notion based on a 60,000 year-old Neanderthal hyoid bone discovered in Israel in 1989.

"To many, the Neanderthal hyoid discovered was surprising because its shape was very different to that of our closest living relatives, the chimpanzee and the bonobo. However, it was virtually indistinguishable from that of our own species. This led to some people arguing that this Neanderthal could speak," A/Professor Wroe said.

"The obvious counterargument to this assertion was that the fact that hyoids of Neanderthals were the same shape as modern humans doesn't necessarily mean that they were used in the same way. With the technology of the time, it was hard to verify the argument one way or the other."

However advances in 3D imaging and computer modelling allowed A/Professor Wroe's team to revisit the question.

"By analysing the mechanical behaviour of the fossilised bone with micro x-ray imaging, we were able to build models of the hyoid that included the intricate internal structure of the bone. We then compared them to models of modern humans. Our comparisons showed that in terms of mechanical behaviour, the Neanderthal hyoid was basically indistinguishable from our own, strongly suggesting that this key part of the vocal tract was used in the same way.

"From this research, we can conclude that it's likely that the origins of speech and language are far, far older than once thought."
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References:

Science Daily. 2014. “Talking Neanderthals challenge the origins of speech”. Science Daily. Posted: March 2, 2014. Available online: http://www.sciencedaily.com/releases/2014/03/140302185241.htm

Friday, April 18, 2014

Candelabra found in Ibiza waters offers clues about medieval navigation routes

The history of medieval navigation on the Iberian peninsula is a great mystery. In the 1970s, a recreational diver found a bronze candelabra in Ibiza which Marcus H. Hermanns, a scientist from the German Archaeological Institute in Madrid, has now unveiled. It is a unique piece from the 10th century which could provide clues on sea routes in the period.

The scientist Marcus H. Hermanns from the German Archaeological Institute in Madrid works on research projects on underwater Spanish archaeological heritage.

He has just finished the catalogue of archaeological sites and pieces found to date underwater off the Balearic coast. "The list is part of the National R&D&I Plan to have an inventory of cultural heritage submerged under the waters of all coastal regions," Hermanns explains.

This collection has involved several years of archiving work, but also diving to check the state of shipwrecks and underwater archaeological sites. "These diving checks were made with the Spanish Guardia Civil's (Civil Guard's) Special Group for Underwater Activities (GEAS in Spanish) of the Ibiza division, and certain locations -- which are now being published -- caught our attention. We also carried out other, more detailed projects, such as analysing a bronze candelabra from the Middle Ages that is unique to the region," the archaeologist adds.

This piece, a description of which is published in the journal Archivo Español de Arqueología (Spanish Archaeology Archive), is unusual because there are not many similar models in the world. It is also unique to the Balearic region and dates back to the 10th century, an era in which marine activities on the Pityusic Islands (Ibiza and Formentera) are widely unknown.

"However, as it belongs to a private collection -- a diver in Ibiza found it in the 1970s -- it is quite a challenge gaining information about it," Hermanns remarks.

From Ibiza to the Muslim colony of Fraxinetum

Archaeologists know the location of the underwater site where the candelabra was found, so a diving check was carried out. It yielded no results, however. As the scientist explains, "the majority of the sea beds around the island, from 30 metres deep, are sandy and there is depth movement. You can be unlucky because the site could be covered on the day you are diving. We conducted several tests to find out the dynamics of the sea floor and the state the site was in."

This candelabra is noteworthy because the seaways that went along Ibiza to get to Mallorca are unknown. Moreover, on the route where it was found, several shipwrecks from the same period were also found in southern France.

"There was a link between the Iberian peninsula and the south of France at least, with a Muslim colony named Fraxinetum, according to the Latin documents preserved. There is also a group of sunken vessels that attest to it; this must have been a supply system for the colony from the south of the peninsula," the scientist claims.

Heermanns stresses that cases like these, in which objects currently held in private collections maintain well-documented account of the archaeological context in which it was found, are rare.

"There are few exceptions. This demonstrates the immense value that could be derived at institutional level, for example in diving federations, from raising awareness among recreational divers about underwater archaeology and the considerable cultural heritage to be found underwater," he emphasises. This candelabra is a unique piece, but coming from a location with no archaeological context, it is hard to imagine what use it had or any possible ritual implications.

"It belongs to the Caliphate era. We are uncertain of its symbology and precise use. For instance, it shows no traces of burning, among other reasons because it was restored differently from those found in investigations. However, it was worthwhile to make the study known to the scientific community because it might give clues on the importance of Ibiza in navigation routes," he concludes.
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References:

Science Daily. 2014. “Candelabra found in Ibiza waters offers clues about medieval navigation routes”. Science Daily. Posted: February 26, 2014. Available online: http://www.sciencedaily.com/releases/2014/02/140226074929.htm

Thursday, April 17, 2014

The pain of social exclusion

'Social' pain hurts physically, even when we see it in others

We would like to do without pain and yet without it we wouldn't be able to survive. Pain signals dangerous stimuli (internal or external) and guides our behaviour. Its ultimate goal is to prioritize escape, recovery and healing. That's why we feel it and why we're also good at detecting it in others. Pain in fact protects not only the individual but also his social bonds. The brain contains circuits related to the more physical aspects of pain and others related to affective aspects. As observed in a study just published by Giorgia Silani, Giovanni Novembre and Marco Zanon of the International School for Advanced Studies (SISSA) of Trieste in the journal Social Cognitive and Affective Neuroscience, social pain activates some brain circuits of physical pain whether we feel it personally or when we experience it vicariously as an empathic response to other people's pain.

The study by Silani and colleagues is innovative since it adopted a more realistic experimental procedure than used in the past and compared behaviours and the results of functional magnetic resonance imaging in the same subjects, during tests involving both physical and social pain. "Classic experiments used a stylized procedure in which social exclusion situations were simulated by cartoons. We suspected that this simplification was excessive and likely to lead to systematic biases in data collection, so we used real people in videos".

The subjects took part in the experimental sessions simulating a ball tossing game, where one of the players was deliberately excluded by the others (condition of social pain). The player could be the subject herself or her assigned confederate. In another series of experiments the subject or her confederate were administered a mildly painful stimulus (condition of physical pain). When the subject was not personally the target of the stimulus, she could witness the entirety of her confederate's experience.

"Our data have shown that in conditions of social pain there is activation of an area traditionally associated with the sensory processing of physical pain, the posterior insular cortex", explains Silani. "This occurred both when the pain was experienced in first person and when the subject experienced it vicariously".

"Our findings lend support to the theoretical model of empathy that explains involvement in other people's emotions by the fact that our representation is based on the representation of our own emotional experience in similar conditions" concludes Silani.
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References:

EurekAlert. 2014. “The pain of social exclusion”. EurekAlert. Posted: February 27, 2014. Available online: http://www.eurekalert.org/pub_releases/2014-02/isoa-tpo022714.php