Thursday, May 21, 2015

English speakers, you stink at identifying smells

Why do English speakers struggle to identify even common smells like cinnamon, asks linguist Asifa Majid. Is it down to language itself, or our environment?

Why study the language of olfaction?
There are centuries-old ideas that humans have evolved to be visual or auditory creatures, and that our senses of smell, taste and touch just aren't as important any more. We're looking to see whether that's reflected in different languages as well.

Are there languages which excel at describing smells?
Speakers of the Aslian languages – found throughout the Malay Peninsula – are particularly good at expressing olfactory experiences. For the Jahai group, for example, who live a hunter-gatherer lifestyle, we found that smell was as easy to talk about as colour – unlike in English.

How many smell words do the Jahai use?
They have about 12 that describe specific smell characteristics. These are words that can only be used for smells. For example, a term pronounced "pl'eng" is used for fresh blood, raw meat, mud, stagnant water, fresh fish, otters, some species of toad... These are different kinds of objects, but there seems to be a smell quality common to them.

What's a good smell-specific word in English?
A term in English that really picks up on a specific kind of smell quality is "musty" – something like when you open a door that's been closed for a long time, or maybe the smell of old books.

How good are English speakers at articulating what they smell?
We gave Jahai speakers and English speakers the same smell and asked them to describe it. Jahai speakers were quick and consistent. With English speakers, nearly everybody gave a different and lengthy description for the same smell. For the smell of cinnamon, for example, one participant went on and on, like "I don't know how to say it" and "I can't get the word" and "like that chewing gum smell" and finally "Big Red gum". It was hard for most English speakers to identify even the common smell of cinnamon.

Why do English speakers struggle when the Jahai don't?
Perhaps it's because the Jahai live in a tropical rainforest, where smells are simply more salient. But there seems to be something culturally different, too: people in the West seem to do everything they can to get rid of smells, and in many contexts odour is a taboo topic. This might be linked to changes in our smell environment since the industrial revolution. If you read stories from the UK or France from before the revolution, there's sewage in the streets and people are using perfume to cover up body odour. These days, we do everything we can to sanitise our environment.

What lessons do you draw from your cross-cultural studies of smell?
Our work with the Jahai is exciting because it shows us that we have the potential to experience our environment in so many different ways. It makes you rethink your way of being in the world.
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Reference:

Landau, Elizabeth. 2015. “English speakers, you stink at identifying smells”. New Scientist. Posted: March 30, 2015. Available online: http://www.newscientist.com/article/mg22530140.300-english-speakers-you-stink-at-identifying-smells.html

Wednesday, May 20, 2015

Earliest humans had diverse range of body types, just as we do today

One of the dominant theories of our evolution is that our genus, Homo, evolved from small-bodied early humans to become the taller, heavier and longer legged Homo erectus that was able to migrate beyond Africa and colonise Eurasia. While we know that small-bodied Homo erectus - averaging less than five foot (152cm) and under 50kg - were living in Georgia in southern Europe by 1.77 million years ago, the timing and geographic origin of the larger body size that we associate with modern humans has, until now, remained unresolved.

But a joint study by researchers at the Universities of Cambridge and Tübingen (Germany), published today in the Journal of Human Evolution, has now shown that the main increase in body size occurred tens of thousands of years after Homo erectus left Africa, and primarily in the Koobi Fora region of Kenya. According to Manuel Will, a co-author of the study from the Department of Early Prehistory and Quaternary Ecology at Tübingen, "the evolution of larger bodies and longer legs can thus no longer be assumed to be the main driving factor behind the earliest excursions of our genus to Eurasia".

Researchers say the results from a new research method, using tiny fragments of fossil to estimate our earliest ancestors' height and body mass, also point to the huge diversity in body size we see in humans today emerging much earlier than previously thought.

"What we're seeing is perhaps the beginning of a unique characteristic of our own species - the origins of diversity," said Dr Jay Stock, co-author of the study from the University of Cambridge's Department of Archaeology and Anthropology. "It's possible to interpret our findings as showing that there were either multiple species of early human, such as Homo habilis, Homo ergaster and Homo rudolfensis, or one highly diverse species. This fits well with recent cranial evidence for tremendous diversity among early members of the genus Homo."

"If someone asked you 'are modern humans 6 foot tall and 70kg?' you'd say 'well some are, but many people aren't,' and what we're starting to show is that this diversification happened really early in human evolution," said Stock.

The study is the first in 20 years to compare the body size of the humans who shared the earth with mammoths and sabre-toothed cats between 2.5 and 1.5 million years ago. It is also the first time that many fragmentary fossils - some as small as toes and tiny ankle bones no more than 5cm long - have been used to make body size estimates.

Comparing measurements of fossils from sites in Kenya, Tanzania, South Africa, and Georgia, the researchers found that there was significant regional variation in the size of early humans during the Pleistocene. Some groups, such as those who lived in South African caves, averaged 4.8 feet tall; some of those found in Kenya's Koobi Fora region would have stood at almost 6 foot, comparable to the average of today´s male population in Britain.

"Basically every textbook on human evolution gives the perspective that one lineage of humans evolved larger bodies before spreading beyond Africa. But the evidence for this story about our origins and the dispersal out of Africa just no longer really fits," said Stock. "The first clues came from the site of Dmanisi in Georgia where fossils of really small-bodied people date to 1.77 million years ago. This has been known for several years, but we now know that consistently larger body size evolved in Eastern Africa after 1.7 million years ago, in the Koobi Fora region of Kenya."

"We tend to simplify our interpretations because the fossil record is patchy and we have to explain it in some way. But revealing the diversity that exists is just as important as those broad, sweeping explanations."

Previous studies have been based on small samples of only 10-15 fossils because techniques for calculating the height and body mass of individuals required specific pieces of bone such as the hip joint or most of a leg bone. Stock and Will have used a sample size three times larger, estimating body size for over 40 specimens contained in collections all over Africa and Georgia, making it the largest comparative study conducted so far.

Instead of waiting for new fossils to be discovered and hoping that they contained these specific bones, Stock and Will decided to try a different approach and make use of previously over-looked fossils. In what Stock describes as a "very challenging project," they spent a year developing new equations that allowed them to calculate the height and body mass of individuals using much smaller bones, some as small as toes. By comparing these bones to measurements taken from over 800 modern hunter-gatherer skeletons from around the world and applying various regression equations, the researchers were able to estimate body size for many new fossils that have never been studied in this way before.

"In human evolution we see body size as one of the most important characteristics, and from examining these 'scrappier' fossils we can get a much better sense of when and where human body size diversity arose. Before 1.7 million years ago our ancestors were seldom over 5 foot tall or particularly heavy in body mass.

"When this significant size shift to much heavier, taller individuals happened, it occurred primarily in one particular place - in a region called Koobi Fora in northern Kenya around 1.7 million years ago. That means we can now start thinking about what regional conditions drove the emergence of this diversity, rather than seeing body size as a fixed and fundamental characteristic of a species," said Stock.
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Reference:

EurekAlert. 2015. “Earliest humans had diverse range of body types, just as we do today”. EurekAlert. Posted: March 26, 2015. Available online: http://www.eurekalert.org/pub_releases/2015-03/uoc-ehh032615.php

Tuesday, May 19, 2015

Study underscores complexity of geopolitics in the age of the Aztec empire

New findings from an international team of archaeological researchers highlight the complexity of geopolitics in Aztec era Mesoamerica and illustrate how the relationships among ancient states extended beyond warfare and diplomacy to issues concerning trade and the flow of goods.

The work was done by researchers from North Carolina State University, the Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Unidad Mérida, El Colegio de Michoacán and Purdue University.

The researchers focused on an independent republic called Tlaxcallan in what is now central Mexico, about 75 miles east of modern Mexico City. Tlaxcallan was founded in the mid-13th century and, by 1500, was effectively surrounded by the Aztec Empire - but never lost its independence. In fact, Tlaxcallan supported Cortés and played a critical role in the Spanish Conquest of Mexico in the 16th century.

The new research focuses on where the people of Tlaxcallan obtained their obsidian in the century before the arrival of Cortés. Obsidian is a volcanic glass that was widely used in everything from household tools and weapons to jewelry and religious objects. But Tlaxcallan did not have a source of obsidian within its territory - so where did it come from?

"It turns out that Tlaxcallan relied on a source we hadn't expected, called El Paredón," says Dr. John Millhauser, an assistant professor of anthropology at NC State and lead author of a paper on the work. "Almost no one else was using El Paredón at the time, and it fell just outside the boundaries of the Aztec Empire. So, one question it raises is why the Aztecs - who were openly hostile to Tlaxcallan - didn't intervene."

One possible explanation is that the Aztecs didn't intervene because it would have been too much effort. "Obsidian was widely available and was an everyday good. It probably wasn't worth the time and expense to try to cut off Tlaxcallan's supply of obsidian from El Paredón because other sources were available," Millhauser says.

The finding drives home how complex international relations were during the Aztec Empire's reign.

"The fact that they got so much obsidian so close to the Aztec Empire makes me question the scope of conflict at the time," Millhauser says. "Tlaxcallan was able to access a source of household and military goods from a source that required it to go right up to the border of enemy territory."

At the same time, the research makes clear that there was an economic rift between Tlaxcallan and the Aztecs. Previous research shows that more than 90 percent of Aztec obsidian came from a source called Pachuca, further to the north. But the new research finds that only 14 percent of the obsidian at Tlaxcallan was from Pachuca - most of the rest came from El Paredón.

For this study, the researchers systematically collected artifacts from the surfaces of stone-walled terraces at the site of the pre-Columbian city of Tlaxcallan. A representative number of the artifacts were then analyzed using x-ray fluorescence. This information was compared with samples from known sources of obsidian in the region to determine where the obsidian artifacts came from.

"All of this drives home the fact that geopolitics mattered for the economies of ancient states," Millhauser says. "Political stances and political boundaries influenced everyday behavior, down to the flow of basic commodities like obsidian. The popular conception of the Aztec Empire as all powerful before the arrival of Cortés is exaggerated. The region was a politically and culturally complicated place."
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Reference:

EurekAlert. 2015. “Study underscores complexity of geopolitics in the age of the Aztec empire”. EurekAlert. Posted: March 25, 2015. Available online: http://www.eurekalert.org/pub_releases/2015-03/ncsu-suc030915.php

Monday, May 18, 2015

Local cults of saints played a role in Scandinavian Christianisation

There is a clear link between the celebration of native saints and the ecclesiastical organisation that emerged in Scandinavia in the 12th century. Yet, according to a new doctoral thesis in history from the University of Gothenburg, important differences can be noted between Sweden and Denmark.

Local cults of saints emerged during the Early Middle Ages in the area of Scandinavia that was separated into the ecclesiastical provinces of Lund and Uppsala, roughly corresponding to modern-day Denmark and Sweden. Dioceses and other institutions were established in both provinces in the 11th and 12th centuries.

A Scandinavian perspective

This first-ever comparative study of all 23 native saints in both provinces yields a comprehensive Scandinavian perspective that has been missing in previous research on European cults of saints.

‘These early cults of saints served several purposes. The celebration of local saints supported the Christianisation, but cults were also a way to confirm sacred places. It wasn’t unusual that churches and monasteries were built in these locations. New sacred places could also be used to support local leaders or to create new pilgrimage sites and thereby facilitate the undertaking of pilgrimages for the new Christians,’ says Sara Ellis Nilsson, author of the thesis.

These saints were often individuals who had lived in the location in question, such as Elin of Skövde, Botvid of Södermanland, Thøger of Vestervig and Margareta of Roskilde. They were important role models for people in areas that had recently been Christianised. All saints were considered to have performed miracles, which were documented in their biographies. Some saints were martyrs, whereas others were canonised based on their good deeds. For example, Elin of Skövde collected money for the construction of a church.

Ellis Nilsson shows that Denmark was interested in papal canonisation much earlier than Sweden, indicating stronger ties to the Papacy.

‘In Denmark, the holy person had to be canonised by the pope in order to be officially celebrated by the church. That wasn’t necessary in Sweden,’ she says.

Medieval church books

Her research on local cults has at times consisted of meticulous detective work to sort through the remains of medieval church books. After the Reformation, these books were cut up in pieces and used as new book covers, often for 17th century account books. One hundred years ago, efforts to catalogue the fragments were initiated. This work has resulted in a digital catalogue of the Swedish fragments, which means that these valuable sources can be used once again.

Ellis Nilsson has studied parchment fragments of church books and other texts, which comprise the earliest preserved evidence of these cults.

‘One can find a lot of information in these texts. The native saints were venerated and celebrated in church and had their own days in the Calendar. For example, in dioceses where they were considered to be important, the saint’s feast day was for everybody to enjoy and not just the priests. This was the case for Elin, who continued to be venerated in the Diocese of Skara for a long time. In contrast, the status of the Danish female saints was not nearly as long-lasting, probably because they did not have enough support from wealthy families and the Church. They were never given their own official feast days,’ says Ellis Nilsson.
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Reference:

Past Horizons. 2015. “Local cults of saints played a role in Scandinavian Christianisation”. Past Horizons. Posted: March 25, 2015. Available online: http://www.pasthorizonspr.com/index.php/archives/03/2015/local-cults-of-saints-played-a-role-in-scandinavian-christianisation

Sunday, May 17, 2015

After learning new words, brain sees them as pictures

When we look at a known word, our brain sees it like a picture, not a group of letters needing to be processed. That's the finding from a Georgetown University Medical Center (GUMC) study published in the Journal of Neuroscience, which shows the brain learns words quickly by tuning neurons to respond to a complete word, not parts of it.

Neurons respond differently to real words, such as turf, than to nonsense words, such as turt, showing that a small area of the brain is "holistically tuned" to recognize complete words, says the study's senior author, Maximilian Riesenhuber, PhD, who leads the GUMC Laboratory for Computational Cognitive Neuroscience.

"We are not recognizing words by quickly spelling them out or identifying parts of words, as some researchers have suggested. Instead, neurons in a small brain area remember how the whole word looks -- using what could be called a visual dictionary," he says. This small area in the brain, called the visual word form area, is found in the left side of the visual cortex, opposite from the fusiform face area on the right side, which remembers how faces look. "One area is selective for a whole face, allowing us to quickly recognize people, and the other is selective for a whole word, which helps us read quickly," Riesenhuber says.

The study asked 25 adult participants to learn a set of 150 nonsense words. The brain plasticity associated with learning was investigated with functional magnetic resonance imaging (fMRI), both before and after training.

Using a specific fMRI technique know as fMRI-rapid adaptation, the investigators found that the visual word form area changed as the participants learned the nonsense words. Before training the neurons responded like the training words were nonsense words, but after training the neurons responded to the learned words like they were real words. "This study is the first of its kind to show how neurons change their tuning with learning words, demonstrating the brain's plasticity," says the study's lead author, Laurie Glezer, PhD. The findings not only help reveal how the brain processes words, but also provides insights into how to help people with reading disabilities, says Riesenhuber. "For people who cannot learn words by phonetically spelling them out -- which is the usual method for teaching reading -- learning the whole word as a visual object may be a good strategy."

In fact, after the team's first groundbreaking study on the visual dictionary was published in Neuron in 2009, Riesenhuber says they were contacted by a number of people who had experienced reading difficulties and teachers helping people with reading difficulties, reporting that learning word as visual objects helped a great deal. That study revealed the existence of a neural representation for whole written real words -- also known as an orthographic lexicon --the current study now shows how novel words can become incorporated after learning in this lexicon.

"The visual word form area does not care how the word sounds, just how the letters of the word look together," he says. "The fact that this kind of learning only happens in one very small part of the brain is a nice example of selective plasticity in the brain."
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Reference:

Science Daily. 2015. “After learning new words, brain sees them as pictures”. Science Daily. Posted: March 24, 2015. Available online: http://www.sciencedaily.com/releases/2015/03/150324183623.htm

Saturday, May 16, 2015

Archaeologists discover Maya 'melting pot'

Archaeologists working in Guatemala have unearthed new information about the Maya civilization's transition from a mobile, hunter-gatherer lifestyle to a sedentary way of life.

Led by University of Arizona archaeologists Takeshi Inomata and Daniela Triadan, the team's excavations of the ancient Maya lowlands site of Ceibal suggest that as the society transitioned from a heavy reliance on foraging to farming, mobile communities and settled groups co-existed and may have come together to collaborate on construction projects and participate in public ceremonies.

The findings, to be published this week in Proceedings of the National Academy of Sciences, challenge two common assumptions: that mobile and sedentary groups maintained separate communities, and that public buildings were constructed only after a society had fully put down roots.

"There has been the theory that sedentary and mobile groups co-exited in various parts of the world, but most people thought the sedentary and mobile communities were separate, even though they were in relatively close areas," said Inomata, a UA professor of anthropology and lead author of the PNAS study. "Our study presents the first relatively concrete evidence that mobile and sedentary people came together to build a ceremonial center."

A public plaza uncovered at Ceibal dates to about 950 B.C., with surrounding ceremonial buildings growing to monumental sizes by about 800 B.C. Yet, evidence of permanent residential dwellings in the area during that time is scarce. Most people were still living a traditional hunter-gatherer-like lifestyle, moving from place to place throughout the rainforest, as they would continue to do for five or six more centuries.

The area's few permanent residents could not have built the plaza alone, Inomata said.

"The construction of ceremonial buildings is pretty substantial, so there had to be more people working on that construction," he said.

Inomata and his colleagues theorize that groups with varying degrees of mobility came together to construct the buildings and to participate in public ceremonies over the next several hundred years. That process likely helped them to bond socially and eventually make the transition to a fully sedentary society.

"This tells us something about the importance of ritual and construction. People tend to think that you have a developed society and then building comes. I think in many cases it's the other way around," Inomata said. "For those people living the traditional way of life, ceremony, ritual and construction became major forces for them to adapt a new way of life and build a new society. The process of gathering for ritual and gathering for construction helped bring together different people who were doing different things, and eventually that contributed to the later development of Mayan civilization."

The transition was gradual, with the Maya making the shift to a fully sedentary agrarian society, reliant on maize, by about 400 or 300 B.C., Inomata said.

"The most fascinating finding is that different peoples with diverse ways of life co-existed in apparent harmony for generations before establishing a more uniform society," said Melissa Burham, a study co-author and a graduate student in the UA School of Anthropology. "Discovering an ancient 'melting pot' is definitely the unexpected highlight of this research."
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Reference:

2015. “Archaeologists discover Maya 'melting pot'”. Phys.Org. Posted: March 23, 2015. Available online: http://phys.org/news/2015-03-archaeologists-maya-pot.html

Friday, May 15, 2015

Archivists unearth rare first edition of the 1815 'Map that Changed the World'

A rare early copy of William Smith's 1815 Geological Map of England and Wales, previously thought lost, has been uncovered by Geological Society archivists. The new map has been digitised and made available online in time for the start of celebrations of the map's 200th anniversary, beginning with an unveiling of a plaque at Smith's former residence by Sir David Attenborough.

The map, the first geological map of a nation ever produced, shows the geological strata of England, Wales and part of Scotland. The newly discovered copy is thought to have been one of the first ten produced by William Smith (1769-1839), who went on to produce an estimated 370 hand-coloured copies of the map in his lifetime.

Now fully restored and digitised, images of the new map can be viewed on the Geological Society's image library from March 23 -- William Smith's birthday. It will also be on display at the Geological Society during a number of events celebrating the map's bicentennial.

Often called 'the Father of English Geology', William Smith pioneered the science of stratigraphy and geological mapping. His map of England and Wales became the basis for all future geological maps of Britain, and influenced geological surveys around the world. 'Smith's importance to the history of our science cannot be overstated' says John Henry, Chair of the Geological Society's History of Geology Group. 'His map is a remarkable piece of work. It helped shape the economic and scientific development of Britain, at a time before geological surveys existed.'

Smith's story was popularised by Simon Winchester's 2001 book, 'The Map that Changed the World', which tells the story of his relationship with the Geological Society, who produced their own geological map of Britain in 1820.

'These maps are extremely rare' says Henry. 'Each one is a treasure, and to have one of the very first produced is tremendously exciting.'

Although it is difficult to estimate the value of individual William Smith maps, an early copy was recently made available for sale at £150,000. The newly discovered map was found by the Society's then Archive Assistant Victoria Woodcock in 2014, during an audit of the Society's archives led by Geological Society Archivist Caroline Lam.

'The map was found among completely unrelated material, so at first I didn't realise the significance of what I'd uncovered' says Woodcock. 'Once we had worked out that it was an early copy of one of the earliest geological maps ever made, I was astonished. It's the kind of thing that anyone working in archives dreams of, and definitely the highlight of my career so far!'

The map was identified as a first edition due to its lack of serial number, and geological features which Smith was known to have updated on later versions.

'The very first batch of maps Smith produced did not have a series number or signature' says Henry. 'Other indications that it is a first edition is the geology depicted on the Isle of Wight, the lack of an engraved line on the Welsh border, and lack of granite around Eskdale in the Lake District.'

Records of the Geological Society's Council minutes from 1815 suggest the map was purchased by the Society in that year for the sum of £5 5s. Since then, its 'disappearance' means it has rarely been exposed to light, preserving the incredibly bright original colours. A number of organisations, including the Geological Society, the Natural History Museum, the British Geological Survey and National Museum Wales, are joining together throughout 2015 to celebrate the bicentennial of William Smith's map through a range of events. 'We're incredibly excited by the discovery' says Geological Society President Professor David Manning. 'It's wonderful that the map has been restored and made publicly available in time for the bicentennial celebrations, and we're very grateful to the sponsors who have made this possible.'
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Reference:

Science Daily. 2015. “Archivists unearth rare first edition of the 1815 'Map that Changed the World'”. Science Daily. Posted: March 23, 2015. Available online: http://www.sciencedaily.com/releases/2015/03/150323075432.htm