Monday, December 9, 2013

European Roots for Native Americans?

An analysis of ancient DNA from a 24,000-year-old Siberian skeleton generates a new model for the original peopling of the Western Hemisphere.

Native Americans may not have descended from East Asians who crossed the Bering Land Bridge more than 15,000 years ago, according to a new genomic analysis of a millennia-old Siberian skeleton. A portion of the nuclear DNA recovered from the upper arm bone of a 4-year-old boy that was buried near the Siberian village of Mal’ta about 24,000 years ago is shared by modern Native Americans and no other group. But the boy appears to have been descended from people of European or western Asian origin.

Eske Willerslev, a University of Copenhagen ancient DNA expert, announced the findings last week at the Paleoamerican Odyssey conference in Santa Fe, New Mexico, and the resulting manuscript is in press at Nature. In addition to finding genome regions shared by modern Native Americans, he and collaborator Kelly Graf of Texas A&M University found that the boy’s Y chromosome and mitochondrial DNA belonged to haplogroups that are found almost exclusively in Europeans and people living in Asia west of the Altai Mountains.

Conspicuously absent from the child’s DNA, however, was any connection to modern East Asians, a genetic relationship present in the genomes of virtually all Native Americans. This means that the population from which the boy came must have included ancestors of modern Native Americans, upsetting the popular belief that the original inhabitants of North, Central, and South America descended directly from East Asians.

According to Science, Willerslev and Graf suggest that at some point before 24,000 years ago, the ancestors of modern Native Americans and those of East Asians split into two genetically distinct groups. The Mal’ta boy belonged to a population that migrated to Siberia from Eurasia and mixed with the second before the newly formed population moved into the New World, eventually populating the Americas.

Previously, the presence of European DNA in the modern Native American genome was attributed to interbreeding after Europeans made contact. This new finding may turn that supposition on its head. “The west Eurasian [genetic] signatures that we very often find in today's Native Americans don't all come from postcolonial admixture,” Willerslev said during his presentation. “Some of them are ancient.”

Though reconstructing humanity’s westward expansion into the New World involves some speculation, recovering the intact DNA of the Mal’ta boy represents a technological feat: his is oldest complete genome of a modern human sequenced to date.
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References:

Grant, Bob. 2013. “European Roots for Native Americans?”. The Scientist. Posted: October 29, 2013. Available online: http://www.the-scientist.com/?articles.view/articleNo/38061/title/European-Roots-for-Native-Americans-/

Sunday, December 8, 2013

Figurines reveal secrets of ancient African rituals

Secrets of sixty remarkable clay figurines – up to 1,400-years-old and excavated by archaeologists from The Universities of Ghana and Manchester, and the Ghana Museums and Monuments Board (GMMB)– are to be revealed at an exhibition which started on 25 October.

The beautiful objects – up to 31cm in height – will take pride of place at the Manchester Museum, part of the University, the first time they will be seen publicly outside Ghana.

Invoking the ancestors

The figurines, including two-headed humans, a chameleon, a crocodile and a man on horseback, are thought by the team to have been used to invoke the help of ancestors to cure illnesses.

Using computed tomography scanning techniques at The University of Manchester, the team revealed hidden channels within the objects which they think had a medicinal function, used for liquid ritual offerings.

The figurines show people with congenital conditions including anencephaly – which still affects children in Africa today.

Others depict costumes, ornaments and weapons that were worn and used, as well as animals that had symbolic roles.

Some figurines in the collection were also possibly ‘scapegoats’, intended as the focus or recipient of disease and misfortune rather than their human keepers.

The figures have been dated to between the 6th and the 14th centuries.

Further analysis by the team, led by Professor Benjamin Kankpeyeng from The University of Ghana working with Professor Timothy Insoll from The University of Manchester, will show what liquid ritual offerings were actually used.

The figurines were found in a village called Yikpabongo in Koma Land in the north of Ghana. They come from two mounds thought to be used as a shrine by the makers of the objects.

Illegal excavations

Because the figurines are highly sought after in the art market, some mounds in the region have been illegally excavated.

They have been added to the International Council of Museums Red List, a register of archaeological material at risk.

Professor Kankpeyeng said: “These figurines are unique to the region and offer an insight into aspects of past human beliefs, ways of understanding and creativity.

“This has not always been possible, where there is no tradition of making representations, or when they simply have not survived.

“Their exquisite and consistent appearance obviously required a great deal of skill, suggesting those who made them were a specialist occupation.

“Unfortunately, some of the mounds have been illegally excavated to obtain figurines to sell and The Ghana Museums and Monuments Board and other national, regional, and local stakeholders continue working hard to combat this.

“The people of the villages of Koma Land have a keen sense of the figurines as part of their heritage and deeply resent the unethical trade in such material.” No connection with current inhabitants

Professor Insoll said: “Little is known about the people who made the figurines, who have no connection with Koma Land’s current inhabitants.

“In fact, we know little in general about the past in this part of Ghana, because there are few historical sources before the late 19th century and oral traditions are scarce.

“But archaeology is unlocking some of the secrets of the past, and this project shows what can be achieved.

“We now know the figurines may have had ritual and medicinal functions and the mounds they were found in were perhaps medicine shrines, or places for disposal of material considered dangerous.

“We also know these people were farmers, who traded with cowry shells, used iron tools and lived in villages, with complex religious beliefs.

“The horse or camel and rider figurine indicates awareness of animals used in long distance travel.

“The people of the villages of Koma Land in Ghana are involved in this fieldwork and have a keen sense of the figurines as part of their heritage.

“So we are proud that this exhibition actively involves Ghanaian archaeologists and museum curators who are coming to Manchester to support it.”
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References:

Past Horizons. 2013. "Figurines reveal secrets of ancient African rituals". Past Horizons. Posted: October 28, 2013. Available online: http://www.pasthorizonspr.com/index.php/archives/10/2013/figurines-reveal-secrets-of-ancient-african-rituals

Saturday, December 7, 2013

One, Two, Buckle My Shoe: Importance of Language to Learning Math

Talk to your toddler. And use numbers when you talk. Doing so may give a child a better head start in math than teaching her to memorize 1-2-3 counting routines.

That's the takeaway of an international study published this week in the online early edition of the Proceedings of the National Academy of Sciences. Led by David Barner, associate professor of psychology and linguistics in the Division of Social Sciences at the University of California, San Diego, the study examined how well children ages 2 to 4 understand number concepts. It has been known since the 1970s that learning to count is different than comprehending what numbers really mean, said Barner, director of the Language and Development Lab at UC San Diego. A youngster who can recite numerals in the correct order, to 10 or even 20, will not necessarily be able to correctly answer "How many?" when presented with a small pile of five or even fewer. It has also been known for a long time that "later mathematical achievements are affected by the very earliest experiences, but it has been difficult to point to what exactly it is about these early experiences that matters," Barner said. So Barner and colleagues -- from University College London, King Saud University, University of Nova Gorica and MIT -- looked into the possible role of language. The researchers found a natural experiment among speakers of Slovenian in the capital Ljubljana and speakers of the Saudi dialect of Arabic. In both cases, in addition to singular and plural forms for words, the languages also make a finer grammatical distinction for sets of two. They have a "dual marker," or a piece of grammar that is similar to a plural, but that speakers use when talking about quantities of exactly two. Children who speak these dual-marking languages seem to grasp the concept of "two" much earlier than their English-speaking counterparts, Barner said, even when the children have received little to no training on counting. In fact, they are faster to begin learning number words than children learning any other language reported so far, including Russian, Japanese and Mandarin Chinese, despite the fact that some of those studied had much more experience with counting routines. "Our study provides the strongest evidence to date that the language a child speaks affects the rate at which they learn number words, and also that hearing number words in naturalistic speech -- not just in counting routines and procedures -- is a critical part of number word learning," Barner said. Interestingly, the early advantage conferred by language seems to disappear when looking at numbers over two and as the children grow. Where there are drastic differences among 2-year-olds who are "two-knowers," by age 4 the English speakers in San Diego have actually surpassed their counterparts in Riyadh and Ljubljana, and more of them understand "three" and higher. "Language provides really rich cues to number meaning," Barner said, "but language only gets you so far." After that, you do need to teach the routines. "We know that early learning about number is a critical foundation to later mathematics performance in the classroom," Barner said, "so it can only be beneficial to also expose kids to speech that contains informative cues to number concepts." In the simplest terms: It is important to teach children to memorize their 1, 2, 3s along with their A, B, Cs. And singing songs like "One, Two, Buckle My Shoe" can't hurt. But it's at least as important to put numbers into natural speech and say to your 12- to 24-month-old "There are two buttons," when pointing to a pair.
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References:

Science Daily. 2013. “One, Two, Buckle My Shoe: Importance of Language to Learning Math”. Science Daily. Posted: October 28, 2013. Available online: http://www.sciencedaily.com/releases/2013/10/131028162057.htm

Friday, December 6, 2013

Common bias known as the 'endowment effect' not present in hunter-gatherer societies

Centuries of economic theory have been based on one simple premise: when given a choice between two items, people make the rational decision and select the one they value more. But as with many simple premises, this one has a flaw in that it is demonstrably untrue.

The fields of psychology and behavioral economics have experimentally identified a laundry list of common biases that cause people to act against their own apparent interests. One of these biases — the mere fact of possessing something raises its value to its owner — is known as the "endowment effect."

A new interdisciplinary study from the University of Pennsylvania has delved into whether this bias is truly universal, and whether it might have been present in humanity's evolutionary past.

The study was led by Coren Apicella, an assistant professor in Penn's School of Arts and Sciences' Department of Psychology, and Eduardo Azevedo, an assistant professor in Wharton's Department of Business Economics and Public Policy. They collaborated with Yale's Nicholas Christakis and the University of California, San Diego's James Fowler.

It will be published in the Common Bias Known as the 'Endowment Effect' Not Present in Hunter-Gatherer SocietiesCommon Bias Known as the 'Endowment Effect' Not Present in Hunter-Gatherer Societies.

A classic endowment effect experiments involves giving participants one of two items, such as a chocolate bar and a mug, and then asking whether they would like to trade for the other. As the starting item is selected at random, there should be a 50 percent chance that participants initially receive the item they like best and thus a 50 percent chance that they will trade.

"What we see, however, is that people trade only about 10 percent of the time," Azevedo said. "Simply telling someone they own something makes them value it more. That is, the way you ask the question changes what item people prefer, unlike what you would expect from rational economic behavior."

One problem with these experiments is that they generally involve participants from so-called "WEIRD" — western, educated, industrialized, rich and democratic — societies. Apicella drew on her decade-long study of the Hadza people of Tanzania to provide a new perspective. The Hadza are one of the last hunter-gatherer societies on Earth, living in small, nomadic camps that communally share nearly all their possessions.

"We wanted to examine whether the endowment effect was something that occurs in non-WEIRD societies, since they represent the vast majority of human populations that have ever existed," Apicella said. "Even if it's not a perfect window into our past, it's at least a different perspective than what you get when you study your average college student. The fact that the Hadza remain relatively isolated from Western culture, media and ideals makes them a good group with which to investigate the history and universality of biases like the endowment effect."

The history of the endowment effect is of particular interest to evolutionary psychologists, as experiments to test its presence in non-human primates, such as orangutans, chimpanzees and gorillas, has been met with mixed results. That some non-human primates exhibit the bias could mean that it was present in the last common ancestor between them and humans, but it could also mean that they learned the behavior by participating in other reward-based studies.

The area of North Tanzania where the Hadza live provided a natural way to further investigate the role of culture in transmitting this bias, as a large lake separates some, but not all, of the camps from a nearby village. People living in the camps on the near side of the lake have much more frequent interactions with tourists and commerce, often buying items from stores in the village, or selling bows and arrows to visitors.

The researchers conducted versions of the endowment effect experiment in several different camps, and compared the results.

In order to avoid bias from items that might be more or less valuable in the environment the Hadza live in, the researchers constructed the experiments so that participants chose between items that had only cosmetic differences. Participants would be given either a package of cookies, with the option to trade it for a different flavor, or given a lighter, with the option to trade it for a different color. They also ensured that the participant knew that the variety he or she received at the start was a random choice, and varied whether the participant got to physically hold the item before given the option to trade it for another variety.

"We wanted to use both food and tools, as experiments with non-human primates show an endowment effect for the former but not the latter," Apicella said. "However, we saw that it didn't make a difference whether a person was choosing between cookies or lighters. The difference-maker was their relative level of isolation from modern life."

"The more isolated Hadza traded about 50 percent of the time — which is what rational people should do," Azevedo said. People near the village traded about 25 percent of the time, which is much closer to the 10 percent we see with Western students."

"To make sure this wasn't a case of the more capitalistic people moving closer to the village, we also asked the people about their social networks," Azevedo said. "The percentage of people who named someone in a distant camp was very small. Quantitatively, it seems impossible that the difference in endowment effect between two camps could be explained by migration."

With that potential caveat accounted for, one explanation for the apparent lack of an endowment effect in the more isolated camps is that the bias is a learned behavior that comes with exposure to capitalistic societies. However, an alternative explanation could be that both groups experience the effect, but it is suppressed in the more communal groups by social pressures.

"We need to study this further to see which explanation holds," Apicella said. "Either way the results suggest that these isolated hunter-gatherers are more rational than the average western consumer when it comes to economic decisions."
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References:

EurekAlert. 2013. “Common bias known as the 'endowment effect' not present in hunter-gatherer societies”. EurekAlert. Posted: October 28, 2013. Available online: http://www.eurekalert.org/pub_releases/2013-10/uop-cbk102813.php

Thursday, December 5, 2013

Huge ancient monument found in Sweden

Archaeologists have discovered a monumental structure with high wooden poles, dated at 400-500 AD in Uppsala, Sweden.

Archaeologists in Sweden have found two long rows of wooden post holes at nearly right angles to each other. One of the rows is a kilometre long and consists of 144 post holes. The other extends at least 500 metres. The holes are spaced every six metres and the rows are 500 metres apart.

“We think the wooden poles were high, perhaps over eight to ten metres. They have been easily spotted from a distance,” says the project leader of the dig, Lena Beronius-Jörpeland, an archaeologist with the Swedish National Heritage Board.

A newer version of such rows is found in Denmark, from the Viking era. But there it served as a defensive wall.

“As this is such a large tract of land, we don’t think these rows of posts would work well as protection. In those days they had castles which served that function, but they were much smaller. Maybe this monument had multiple functions,” said Beronius-Jörpeland to the Swedish newspaper Dagens Nyheter.

Connection with the royal burial mounds

The site is just a few hundred metres from a well-known landmark, the Royal Mounds [Kungshögarna]. These are from the decades around 600 AD and had significant functions for religion and trade.

The researchers are speculating about links between the monumental linear structures and the burial mounds. The area they are in is one of the most important known from the Swedish Iron Age.

“We know there was some sort of judicial court associated with the kings who are buried in the mounds. It’s tempting to speculate that this had something to do with the newly discovered monument. Maybe it was intended as a visual manifestation of power,” says Beronius-Jörpeland.

Inspiration from abroad

The excavation has revealed animal bones in some of the holes where pillars once stood. A puppy skeleton was dug out of one, which indicates that it was sacrificed when the post was erected or the construction was completed.

The excavation of the extensive monumental structure will continue as researchers seek information on possible similar constructions elsewhere in Europe or skirting the Mediterranean. The idea is to find out whether mighty leaders who ordered the construction in  Gamla Uppsala got their inspiration from abroad.
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References:

Veka, Camilla. 2013. “Huge ancient monument found in Sweden”. Science Nordic. Posted: October 26, 2013. Available online: http://sciencenordic.com/huge-ancient-monument-found-sweden

Wednesday, December 4, 2013

Viking 'Parliament' Discovered Beneath Parking Lot in Scotland

A Viking parliamentary site that dates to the 11th century has been found beneath a parking lot in Scotland.

The site, located in the town of Dingwall, Scotland, was dubbed a "Thing" site, referring to its name in antiquity. Like other Thing sites, this one was likely a place where ancient Norsemen gathered to settle legal disputes, uphold laws and make key political decisions.

"It's a fantastic find, really," said Oliver J. T. O'Grady, the director of the site's excavations and an archaeologist who runs an archaeological consulting firm called OJT Heritage. "No one's had dating [information] from a Thing site in Scotland."

The Thing

Historians had long wondered whether Dingwall was a site of a Viking parliamentary gathering known as the Thing because the word Dingwall probably originated from the word thingvellir, which means "the field of the assembly."

Such Thing sites are scattered from Iceland to Norway to the Shetland Islands, and Norsemen traveled from far and wide to get to the seasonal gatherings, often to settle disputes that would otherwise end in bloodshed. But Things were held mostly at open-air fields, and people only stayed temporarily, leaving relatively few archaeological traces of their presence.

"Many archaeologists have said, 'How do you find the archaeology of a bunch of people gathering together?'" O'Grady told LiveScience.

O'Grady and his colleagues at The Thing Project, which works on similar sites around Europe, were not deterred, because traces of temporary dwelling booths had turned up at other Thing sites.

Digging up democracy

Using historical records, the team found a mound near the inlet of an estuary in Dingwall that was called the moothill, or assembly mound, in the 13th century. Later on, Scottish earls were buried there. In 1947, local authorities bulldozed the top of the mound and turned the area into a parking lot. (Parking lots seem to be rich sources of history in the U.K. — Richard III's skeleton was found underneath a parking lot, as was a medieval knight in Scotland.)

The team dug a small trench across the mound and used radioactive carbon isotopes, or atoms of carbon with different molecular weights, to date the charcoal found in the soil. (These radioactive isotopes decay at different rates and can be used to date soils and objects.)

The team found that some of the upper layers of the soil date to the medieval period, likely when it was called the moothill, and contain shards of pottery and fragments of an iron vessel.

But below that, the team found the first layers that were used to construct the mound, with soil dating to around the 11th century.

By this period of history, the Vikings were no longer feared marauders sailing the seas and raiding Europe. Instead, the people who gathered at Dingwall were more likely subjects of Norse kings who ruled from the Orkney and Shetland Islands.

No one knows yet who built the site, though the sheer size of the mound suggests it was a fairly significant undertaking that required a lot of political power and resources.

No historical documents mention a Thing gathering site near the region, but Earl Thorfinn the Mighty came down from the Orkney Islands at the time and fought a battle in the general region.

"He would certainly have had a political reason to make a statement," O'Grady said.
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References:

Ghose, Tia. 2013. “Viking 'Parliament' Discovered Beneath Parking Lot in Scotland”. Live Science. Posted: October 24, 2013. Available online: http://www.livescience.com/40674-scotland-viking-parliament-spot-found.html

Tuesday, December 3, 2013

Ancient Magician's Curse Tablet Discovered in Jerusalem

A lead curse tablet, dating back around 1,700 years and likely written by a magician, has been discovered in a collapsed Roman mansion in Jerusalem, archaeologists report.

The mansion, which is being excavated by the Israel Antiquities Authority in the Givati Parking Lot, is located in what is known as the "City of David," an area that holds at least 6,000 years of human occupation. The mansion itself covers at least 2,000 square meters (about half an acre) and contains two large open courtyards adjacent to each other. It was in use between the late third century and A.D. 363, when it was destroyed in a series of earthquakes on May 18 or 19.

The text is written in Greek and, in it a woman named Kyrilla invokes the names of six gods to cast a curse on a man named Iennys, apparently over a legal case.

"I strike and strike down and nail down the tongue, the eyes, the wrath, the ire, the anger, the procrastination, the opposition of Iennys," part of the curse reads in translation. Kyrilla asks the gods to ensure that "he in no way oppose, so that he say or perform nothing adverse to Kyrilla … but rather that Iennys, whom the womb bore, be subject to her…"

To obtain her goal Kyrilla combined elements from four religions, Robert Walter Daniel, of the Institut für Altertumskunde at the University of Cologne, told LiveScience in an email. Of six gods invoked, four of them are Greek (Hermes, Persephone, Pluto and Hecate), one is Babylonian (Ereschigal) and one, Abrasax, is Gnostic, a religion connected to early Christianity. Additionally, the text contains magic words such as "Iaoth" that have a Hebrew/Judaism origin.

A professional magician likely created the curse for Kyrilla, who may have literally used a hammer and nails to perform a magical rite that enhanced the effectiveness of the curse, Daniel said.

"The hammering and nailing is a form of gaining control over the person(s) targeted in magical texts," he wrote in the email.

Kyrilla and her curse-recipient, both probably members of the Roman middle or upper class, were likely in some legal dispute, as the curse tablet bears similarities to others found in Cyprus that are known to have been used in legal cases. Additionally the word "opposition" in this text hints at a legal matter.

Exploring the mansion

The newfound artifacts hint at the wealth the occupants of the mansion would have enjoyed and include a miniature head of a boxer athlete used as a scale-weight and several gems, including one engraved with an image of Cupid holding a torch.

The curse tablet itself was excavated in the northwest part of the mansion. While the second-floor room where the tablet was originally placed has collapsed, the artifacts excavated near the tablet provide hints about what the room may have looked like when in use.

Archaeologists Doron Ben Ami and Yana Tchekhanovets, both with the Israel Antiquities Authority, told LiveScience in an email they discovered the remains of mosaics and frescos that contain geometric and floral motifs near the tablet. They also found carved bone fragments from a box that depict the "Triumph of Dionysus," a Greek god, along with maritime imagery such as seahorses.

The team also uncovered roof tiles in the mansion that contain the stamp of the Roman 10th legion, a unit that, for a time, was stationed in Jerusalem. "This practice is common for all the provinces of the Roman Empire. In peaceful times soldiers were responsible for 'civil engineering': They built roads and aqueducts, produced tiles and bricks, etc. The 10th legion produced so many tiles, that it was enough for many more years of construction activity in the city, long after the legion itself left Jerusalem," Ben Ami and Tchekhanovets said.

The researchers also found female figurines, probably depicting a goddess. They were likely used in a "private cult" whose members included residents of the mansion. These figurines were found at or below floor level and may not have been part of the second-floor room that the curse was placed in.

The researchers do not know the purpose of this second-floor room. However, Iennys appears to have been connected to it to such a degree that the curse tablet was placed there intentionally. "Since the curse is directed against Iennys it might have been hidden in or close to a place that he frequented," Daniel wrote in the email. Perhaps lennys lived or worked in the mansion or a courtroom was located near the second floor room, Daniel said.

The discovery was detailed recently in the journal Zeitschrift für Papyrologie und Epigraphik.
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References:

Jarus, Owen. 2013. “Ancient Magician's Curse Tablet Discovered in Jerusalem”. Live Science. Posted: Available online: http://www.livescience.com/40638-ancient-curse-tablet-discovered-in-jerusalem.html