Wednesday, January 29, 2014

Neanderthal ancestry in present-day humans



More than thirty thousand years ago, Homo sapiens migrating out of Africa began encountering Neanderthals, a lineage that had diverged from modern humans hundreds of thousands of years before. Despite their differences, Homo sapiens and Neanderthals mingled, and over time, produced children with genes from both lineages. Today, the biological remnants of that collision between two distinct populations remain alive in the genomes of humans with European and Asian ancestry.

Now, Howard Hughes Medical Institute (HHMI) researchers at Harvard Medical School have analyzed exactly which areas of the human genome retain segments of Neanderthal DNA, passed down throughout the generations. The findings were published January 29, 2014 in Nature.

"The goal was to understand the biological impact of the gene flow between Neanderthals and modern humans," says David Reich, an HHMI investigator at Harvard Medical School and the lead scientist on the new research. "We reasoned that when these two groups met and mixed, some new traits would have been selected for and remained in the human genome, while some incompatibilities would have been selected against and removed."

Reich has been interested in what happens when populations collide. "Throughout history, groups of humans have been on the move. Until recently, researchers did not have the ability to learn much about what happened when two populations met each other, and in particular whether they mixed or one replaced the other," Reich says. What really happens, he argues, is that populations mix, and that later people carry DNA from both ancestral groups.

In late 2013, Reich was one of the leaders of a team that published the complete genome of a Neanderthal woman, based on analysis of DNA isolated from a toe bone discovered in modern-day Siberia. To determine how the human-Neanderthal genetic mixing may have played out, Reich and his colleagues compared that completed Neanderthal genome with the genomes of 1,004 present-day humans from around the globe.

"If a gene variant is absent in Africans today, but present in modern day non-Africans as well as the Neanderthal genome, that's good evidence that it originates from Neanderthals," Reich says. Since humans met Neanderthals as they migrated out of Africa, those populations that remained in Africa had little contact or genetic mixing with Neanderthals. Reich's group also leveraged other genetic information, including the size of different gene fragments, to determine whether genes were inherited from Neanderthals or not.

The researchers found that today, humans in east Asia have, on average, more of their genome originating from Neanderthals than Europeans, and modern-day Africans have little or none. Those findings confirmed previous studies. But then, the scientists took their analysis a step further and examined which genes most often have Neanderthal ancestry in present-day people. They found that some genes had variants of Neanderthal origin in more than sixty percent of Europeans or Asians, while other genes were never of Neanderthal heritage.

The scientists discovered that the genetic changes most often inherited from Neanderthals were disproportionately in genes related to keratin, a component of skin and hair.

"This suggests that as humans were adapting to the non-African environment they were moving into, they may have been able to exploit adaptations that Neanderthals had already achieved," Reich says. More work is needed, however, to show the exact biological implications of the Neanderthal keratin genes and how they differ from the versions of keratin related proteins that would have already been present in modern humans.

His group analyzed not only which Neanderthal genes remain in the human population today, but also which parts of today's genomes lack Neanderthal genes altogether.

"The most interesting findings were about the places in the genome that are devoid of Neanderthal genes – 'Neanderthal ancestry deserts'," says Reich. "At these locations, Neanderthal genetic material was not tolerated by modern humans and removed by the action of natural selection."

The most striking area of the human genome that lacked Neanderthal genes was the X chromosome—one of the sex chromosomes. In humans, women have two X chromosomes and men have an X and a Y chromosome. The team's observation that the X chromosome had very little Neanderthal ancestry suggested something the scientists hadn't predicted -- a biological phenomenon called hybrid sterility. When two organisms are distantly related, Reich explains, genes related to fertility, inherited on the X chromosome, can interact poorly with genes elsewhere in the genome. The interference between the pairs of genes can render males—who only have one X chromosome—infertile.

"When you have populations that have sufficiently diverged, this male-only sterility can occur," Reich says.

To confirm whether hybrid sterility could have occurred during the interbreeding between modern humans and Neanderthals, Reich's team looked at whether genes expressed in the testes were more or less enriched in Neanderthal DNA. Indeed, genes important for the functioning of the testes had a particularly low inheritance of Neanderthal ancestry. The combined evidence that both the testes and the X chromosome lack Neanderthal DNA, Reich says, suggests that modern human males who inherited a Neanderthal X chromosome often may have been unable to have children, and therefore pass along this X chromosome. Today, that translates into a near- absence of Neanderthal DNA on the X chromosomes of humans.

"It tells us that when Neanderthals and modern humans met and mixed, they were at the very edge of being biological compatible," he says.

Further studies on the legacy of Neanderthal genes in human biology could help shed light on not only human history, but the overall biological idea of hybrid sterility.

"The other direction we want to go is to use this information as a tool for understanding human disease genes," Reich adds. Already, the new study revealed that genetic changes that affect risk for lupus, diabetes, and Crohn's Disease likely originate from Neanderthals.

Monday, January 27, 2014

300,000-Year-Old Hearth Found in Israel


Humans, by most estimates, discovered fire over a million years ago. But when did they really begin to control fire and use it for their daily needs? That question – one which is central to the subject of the rise of human culture – is still hotly debated. A team of Israeli scientists recently discovered in the Qesem Cave, an archaeological site near present-day Rosh Ha’ayin, the earliest evidence – dating to around 300,000 years ago – of unequivocal repeated fire building over a continuous period. These findings not only help answer the question, they hint that those prehistoric humans already had a highly advanced social structure and intellectual capacity.

Excavations in Qesem Cave have been ongoing since 2000. The team is headed by Profs. Avi Gopher and Ran Barkai of Tel Aviv University. Dr. Ruth Shahack-Gross of the Kimmel Center for Archeological Science at the Weizmann Institute has been involved in this archaeological research since excavations began, and she collects samples on-site for later detailed analysis in the lab. Shahack-Gross, whose expertise is in the identification of archaeological materials, identified a thick deposit of wood ash in the center of the cave. Using infrared spectroscopy, she and her colleagues were able to determine that mixed in with the ash were bits of bone and soil that had been heated to very high temperatures. This was conclusive proof that the area had been the site of a large hearth.

Next, Shahack-Gross tested the micro-morphology of the ash. To do this, she extracted a cubic chunk of sediment from the hearth and hardened it in the lab. Then she sliced it into extremely thin slices – so thin they could be placed under a microscope to observe the exact composition of the materials in the deposit and reveal how they were formed. With this method, she was able to distinguish a great many micro-strata in the ash – evidence for a hearth that was used repeatedly over time. These findings were published in the Journal of Archaeological Science.

Around the hearth area, as well as inside it, the archaeologists found large numbers of flint tools that were clearly used for cutting meat. In contrast, the flint tools found just a few meters away had a different shape, designed for other activities. Also in and around the area were large numbers of burnt animal bones – further evidence for repeated fire use for cooking meat. Shahack-Gross and her colleagues have shown that this organization of various “household” activities into different parts of the cave points to an organization of space – and a thus kind of social order – that is typical of modern humans. This suggests that the cave was a sort of base camp that prehistoric humans returned to again and again. “These findings help us to fix an important turning point in the development of human culture – that in which humans first began to regularly use fire both for cooking meat and as a focal point – a sort of campfire – for social gatherings,” she says. “They also tell us something about the impressive levels of social and cognitive development of humans living some 300,000 years ago.” The researchers think that these findings, along with others, are signs of substantial changes in human behavior and biology that commenced with the appearance in the region of new forms of culture – and indeed a new human species – about 400,000 years ago.

Friday, January 24, 2014

Discovered in Israel: Major church with a splendid mosaic from the Byzantine period





Photographic credit: AFP PHOTO/MENAHEM KAHANA

The discovery was made during a salvage excavation as part of development work by the Israel Land Authority prior to the construction of a new neighborhood at Moshav Aluma, near Pelugot Junction * Israel Antiquities Authority archaeologists say, "The church probably served as a center of Christian worship for neighboring communities."



Photographic credit: Yoli Shwartz, Dr. Davida Dagan. courtesy of the Israel Antiquities Authority


Impressive archaeological finds including a major church some 1,500 years old with a magnificent mosaic and five inscriptions were uncovered during Israel Antiquities Authority salvage excavations, prior to the construction of a new neighborhood at Moshav Aluma in Shafir Regional Council, near Pelugot Junction. The excavations were directed by archaeologists Dr. Daniel Varga and Dr. Davida Dagan, and funded by the Israel Land Authority.

According to archaeologist Dr. Daniel Varga, directing the excavations on behalf of the Israel Antiquities Authority, "An impressive basilica building was discovered at the site, 22 meters long and 12 meters wide. The building consists of a central hall with two side aisles divided by marble pillars. At the front of the building is a wide open courtyard (atrium) paved with a white mosaic floor, and with a cistern. Leading off the courtyard is a rectangular transverse hall (narthex) with a fine mosaic floor decorated with colored geometric designs; at its center, opposite the entrance to the main hall, is a twelve-row dedicatory inscription in Greek containing the names Mary and Jesus, and the name of the person who funded the mosaic's construction."

The main hall (the nave) has a colored mosaic floor adorned with vine tendrils to form forty medallions. The medallions contain depictions of different animals, including: zebra, leopard, turtle, wild boar, various winged birds and botanical and geometric designs. Three medallions contain dedicatory inscriptions in Greek commemorating senior church dignitaries: Demetrios and Herakles. The two were heads of the local regional church. On both sides of the central nave are two narrow halls (side aisles), which also have colored mosaic floors depicting botanical and geometric designs, as well as Christian symbols.

A pottery workshop, mainly for the production of jars, was also uncovered during the excavations and yielded numerous finds, including: amphorae, cooking pots, kraters, bowls and different kinds of oil lamps. Glass vessels typical of the Byzantine period were also discovered at the site. The finds indicate a rich and flourishing local culture.

This church is part of a large and important Byzantine settlement that existed in the region. The settlement was located next to the main road running between Ashkelon on the sea coast to the west, and Beit Guvrin and Jerusalem to the east. Excavations by the Israel Antiquities Authority along this road have revealed other communities from the same period, but no churches have been found in them. The recently uncovered church may have served as a center for Christian worship for all the surrounding communities. Wine presses and pottery workshops found in the region attest to the economy of the local residents during the Byzantine period, who made their living from the production and exportation of wine via the coast to the entire Mediterranean region.

As for the future of the site, it has been decided to cover it over and preserve it for future generations. The magnificent mosaic that has come to light will be conserved, removed from the site and displayed to the public at a regional museum or visitors' center.

Thursday, January 23, 2014

Sea Peoples Settled In Jordan Valley (the biblical city of Jabesh Gilead)


Swedish archaeologists in Jordan led by Professor Peter M. Fischer from the University of Gothenburg have excavated a nearly 60-metre long well-preserved building from 1100 B.C. in the ancient settlement Tell Abu al-Kharaz. The building is from an era characterised by major migration.


Reconstruction of the building from 1100 B.C.

New finds support the theory that groups of the so-called Sea Peoples emigrated to Tell Abu al-Kharaz. They derive from Southern or Eastern Europe and settled in the Eastern Mediterranean region all the way to the Jordan Valley.

‘We have evidence that culture from present Europe is represented in Tell Abu al-Kharaz. A group of the Sea Peoples of European descent, Philistines, settled down in the city,’ says Peter Fischer. ‘We have, for instance, found pottery resembling corresponding items from Greece and Cyprus in terms of form and decoration, and also cylindrical loom weights for textile production that could be found in central and south-east Europe around the same time.’

Tell Abu al-Kharaz is located in the Jordan Valley close to the border to Israel and the West Bank. It most likely corresponds to the biblical city of Jabesh Gilead. The Swedish Jordan Expedition has explored the city, which was founded 3200 B.C. and lasted for almost 5 000 years. The first excavation took place in 1989 and the most recent in autumn 2013. All in all, 16 excavations have been completed.

Peter M. Fischer and his team of archaeologists and students have surveyed an urban settlement that flourished three times over the 5 000 years: around 3100–2900 B.C. (Early Bronze Age), 1600–1300 B.C. (Late Bronze Age) and 1100–700 B.C. (Iron Age). These are the local periods; in Sweden, they occurred much later.

Remarkably well-preserved stone structures have been exposed during the excavations. The finds include defensive walls, buildings and thousands of complete objects produced locally or imported from south-east Europe.

‘What surprises me the most is that we have found so many objects from far away. This shows that people were very mobile already thousands of years ago,’ says Fischer.

The scientists have made several sensational finds in the last three years, especially during the excavation of the building from 1100 B.C. where containers still filled with various seeds were found. There are also finds from Middle Egypt that were exported to Tell Abu al-Kharaz as early as 3100 B.C.

The exploration of the 60-metre long building discovered in 2010 continued during the most recent excavation. It was originally built in two levels of which the bottom level is still standing with walls reaching 2.5 metres in height after more than 3 000 years.

The archaeologists found evidence indicating that the Philistines who lived in the building together with local people around 1100 B.C. utilised a defence structure from 3 000 B.C. in the form of an old city wall by constructing their building on top of it. In this way, they had both easy access to building material and a solid surface to build on.

‘One of our conclusions after the excavation is that ”Jordanian culture” is clearly a Mediterranean culture even though the country does not border the Mediterranean Sea. There were well-organised societies in the area long before the Egyptian pyramids were built,’ says Peter M. Fischer.

Thursday, January 16, 2014

Nordic "grog" proves presence of a trading network across Europe -- more than 3,000 years ago


As early as at least 1500-1300 BC Nordic peoples were imbibing an alcoholic "grog" or extreme hybrid beverage rich in local ingredients, including honey, bog cranberry, lingonberry, bog myrtle, yarrow, juniper, birch tree resin, and cereals including wheat, barley and/or rye -- and sometimes, grape wine imported from southern or central Europe.

New research published in the Danish Journal of Archaeology examines evidence derived from samples inside pottery and bronze drinking vessels and strainers from four sites in Denmark and Sweden. The research proves the existence of an early, widespread, and long-lived Nordic grog tradition, one with distinctive flavors and probable medicinal purposes -- and the first chemically attested evidence for the importation of grape wine from southern or central Europe as early as 1100 BC, demonstrating both the social and cultural prestige attached to wine, and the presence of an active trading network across Europe -- more than 3,000 years ago.

"Far from being the barbarians so vividly described by ancient Greeks and Romans, the early Scandinavians, northern inhabitants of so-called Proxima Thule, emerge with this new evidence as a people with an innovative flair for using available natural products in the making of distinctive fermented beverages," notes Dr. Patrick E. McGovern, lead author of the paper. "They were not averse to adopting the accoutrements of southern or central Europeans, drinking their preferred beverages out of imported and often ostentatiously grand vessels. They were also not averse to importing and drinking the southern beverage of preference, grape wine, though sometimes mixed with local ingredients."

To reach their conclusions the researchers, based at the University of Pennsylvania Museum of Archaeology and Anthropology, obtained ancient residue samples from four sites in a 150-mile radius of southern Sweden and encompassing Denmark.

The oldest, dated 1500 -- 1300 BC, was from Nandrup in northwestern Denmark, where a warrior prince had been buried in an oak coffin with a massively hafted bronze sword, battle-ax, and pottery jar whose interior was covered with a dark residue that was sampled.

A second Danish sample, dated to a later phase of the Nordic Bronze Age from about 1100 -- 500 BC, came from a pit hoard at Kostr├Žde, southwest of Copenhagen. A brownish residue filling a perforation of a bronze strainer, the earliest strainer yet recovered in the region, was sampled.

A third Danish sample was a dark residue on the interior base of a large bronze bucket from inside a wooden coffin of a 30-year-old woman, dating to the Early Roman Iron Age, about 200 BC, at Juellinge on the island of Lolland, southwest of Kostr├Žde. The bucket was part of a standard, imported Roman wine-set, and the woman held the strainer-cup in her right hand.

A reddish-brown residue filling the holes and interior of a strainer-cup, again part of imported Roman wine-set, provided the fourth sample. Dating to the first century AD, the strainer-cup was excavated from a hoard, which also included a large gold torque or neck ring and a pair of bronze bells, at Havor on the Swedish island of Gotland in the Baltic Sea.

According to Dr. McGovern, the importation of southern wine grew apace in the Bronze and Iron Ages, and eventually eclipsed the grog tradition -- but never completely. Many of the ingredients in Nordic grog went on to be consumed in birch beer and as the principal bittering agents (so-called gruit) of medieval beers, before hops gained popularity, and the German purity law (Reinheitsgebot) which limited ingredients of beer to barley, hops and water was enacted in Bavaria in 1516 and eventually became the norm in northern Europe.

"About the closest thing to the grog today is produced on the island of Gotland in the Baltic Sea," Dr. McGovern noted. "You can taste Gotlandsdryka in farmhouses. It's made from barley, honey, juniper, and other herbs like those in the ancient version."


Tuesday, January 14, 2014

First farmers and stockbreeders painted with the same pigments that their hunters ancestors



The first of the analyzed figures, depicting a bovid, belongs to the Levantine art practiced by the nomadic hunters-gatherers who inhabited the Iberian Peninsula about 10,000 years ago. On the other hand, the second figure, depicting a quadruped, has a schematic style, developed by the first producers, farmers and stockbreeders who lived in the area between 6,500 and 3,500 years ago. The first style is characterized by the naturalism of its shapes and scenes, while the second outlines its reasons, sometimes even reaching abstraction.

The artists used iron oxides and terrigenous as pigments. These materials are easily found in the environment of the analyzed shelters: the Abrigo Grande de Minateda, the most emblematic to define the origin and evolution of rock art in the Mediterranean Basin of the Iberian Peninsula, and the Abrigo del Barranco de la Mortaja.

Alberto Jorge, CSIC researcher at the National Museum of Natural Sciences, states: "The compositions of the pigments used in both styles, separated by several millenniums in time, are identical, which means that the artists did not turn to intentioned recipes as it was previously thought. The truth is that it is an abundant and good-quality pigmenting material that was easy to find nearby".

New interpretations

Another conclusion of the work has implications in the research methodology of the pigments of rock art outdoors. The presence of calcium oxalate would prove that pigment and carrier merged with the outer layer over the centuries. Jorge explains: "This result would question the studies conducted so far, based on distinguishing three stratigraphic layers – surface, pigment and patina-, as these are continuously merged and altered, which introduces a clear random factor in the dating". Researchers have also detected the presence of certain fatty acids, which would suggest that when pigments were processed, applied or stored, could come into contact with animal skins.

CSIC researcher adds: "From now on, we need to be very cautious when we talk about rituals in the preparation of pigments, as these interpretations came up when substances such as calcium phosphates, interpreted as charred and crushed bones, were found in the pigments. These extrapolations are not correct since we also found these substances in the rocky substrate itself".

Monday, January 13, 2014

The Surprising Diets of the Middle and Lower Class in Pompeii



University of Cincinnati archaeologists are turning up discoveries in the famed Roman city of Pompeii that are wiping out the historic perceptions of how the Romans dined, with the rich enjoying delicacies such as flamingos and the poor scrounging for soup or gruel.

Steven Ellis, a University of Cincinnati associate professor of classics, will present these discoveries on Jan. 4, at the joint annual meeting of the Archaeological Institute of America (AIA) and American Philological Association (APA) in Chicago.

UC teams of archaeologists have spent more than a decade at two city blocks within a non-elite district in the Roman city of Pompeii, which was buried under a volcano in 79 AD. The excavations are uncovering the earlier use of buildings that would have dated back to the 6th century.

Ellis says the excavation is producing a complete archaeological analysis of homes, shops and businesses at a forgotten area inside one of the busiest gates of Pompeii, the Porta Stabia.

The area covers 10 separate building plots and a total of 20 shop fronts, most of which served food and drink. The waste that was examined included collections from drains as well as 10 latrines and cesspits, which yielded mineralized and charred food waste coming from kitchens and excrement. Ellis says among the discoveries in the drains was an abundance of the remains of fully-processed foods, especially grains.

“The material from the drains revealed a range and quantity of materials to suggest a rather clear socio-economic distinction between the activities and consumption habits of each property, which were otherwise indistinguishable hospitality businesses,” says Ellis. Findings revealed foods that would have been inexpensive and widely available, such as grains, fruits, nuts, olives, lentils, local fish and chicken eggs, as well as minimal cuts of more expensive meat and salted fish from Spain. Waste from neighboring drains would also turn up less of a variety of foods, revealing a socioeconomic distinction between neighbors.

A drain from a central property revealed a richer variety of foods as well as imports from outside Italy, such as shellfish, sea urchin and even delicacies including the butchered leg joint of a giraffe.

“That the bone represents the height of exotic food is underscored by the fact that this is thought to be the only giraffe bone ever recorded from an archaeological excavation in Roman Italy,” says Ellis. “How part of the animal, butchered, came to be a kitchen scrap in a seemingly standard Pompeian restaurant not only speaks to long-distance trade in exotic and wild animals, but also something of the richness, variety and range of a non-elite diet.”

Deposits also included exotic and imported spices, some from as far away as Indonesia.

Ellis adds that one of the deposits dates as far back as the 4th century, which he says is a particularly valuable discovery, since few other ritual deposits survived from that early stage in the development of Pompeii.

“The ultimate aim of our research is to reveal the structural and social relationships over time between working-class Pompeian households, as well as to determine the role that sub-elites played in the shaping of the city, and to register their response to city-and Mediterranean-wide historical, political and economic developments. However, one of the larger datasets and themes of our research has been diet and the infrastructure of food consumption and food ways,” says Ellis.

He adds that as a result of the discoveries, “The traditional vision of some mass of hapless lemmings – scrounging for whatever they can pinch from the side of a street, or huddled around a bowl of gruel – needs to be replaced by a higher fare and standard of living, at least for the urbanites in Pompeii.”

Three Rare 2,000 Years Old Fabrics that were Dyed with an Extract from the Murex Snail Found in Israel



Thousands of fabrics dating to the Roman period have been discovered in the Judean Desert and regions of the Negev and the ‘Arava. Until recently, only two fabrics had been discovered that were colored with dye extracted from the murex snail. Now, within the framework of a study conducted by Dr. Na‘ama Sukenik of the Israel Antiquities Authority, three other rare fabrics belonging to pieces of prestigious textiles were identified. They might have been used as clothing in the Roman period.

These prestigious textiles, from the Wadi Murabba‘at caves located south of Qumran, were revealed in a study that analysis the dye of 180 textiles specimens from the Judean Desert caves. Among the many textiles, most of which were dyed using substances derived from plants, were two purple-bordeaux colored textiles – parts of tunics that were double dyed utilizing two of the most expensive materials in antiquity: Murex trunculus (Hexaplex trunculus) and American Cochineal insect .

A third textile, made of wool, indicating the thread fibers were dyed by exposing them to sunlight or heated after having been dyed, represent another use of the murex snail for achieving a shade of blue, and it is possible that the item in question is an indigo fabric made by means of a technique similar to making the tekhelet (blue)in a tzitzit.
The importance of this fabric is extremely significant as there are practically no parallels for it in the archaeological record. .

The testing of the fabrics, performed by Dr. Orit Shamir of the Israel Antiquities Authority, revealed that the two purple textiles were spinning in a unique manner characteristic of imported textiles, whereas the blue textile was spinning in the same fashion as the local textiles.

Of all of the dyes that were in use, purple is considered the most prestigious color of the earlier periods; however it seems the public’s fondness for this reached its peak in the Hellenistic-Roman period. The purple dyed fabrics attested to the prestige of the garment and the social status of its owner. There were times when the masses were forbidden from dressing in purple clothing, which was reserved for only the emperor and his family. These measures only served to increase the popularity of that color, the price of which soared and was equal to that of gold.

It is difficult to know for certain how such prestigious fabrics came to be in the Murabba‘at caves. They might have been part of the property belonging to Jewish refugees from the time of the Bar-Kokhba revolt and demonstrate their economic prosperity prior to the outbreak of the uprising.

Another possibility is that they were part of the possessions of a small Roman unit, which on the basis of the artifacts was stationed in the Murabba‘at caves following the Bar Kokhba revolt. It is likely these same soldiers brought some of their belongings from overseas to Israel and others they purchased from the local Jewish population during their service in the country.

The three fabrics shed light on the Murabba‘at caves and represent the most prestigious colors in antiquity: indigo, purple and crimson.

Tuesday, January 7, 2014

Ancient Artists Used Palace Floor as a Creative Canvas


The floors of Greek Bronze Age palaces were made of plaster that was often incised and painted with grids containing brightly colored patterns and/or marine animal figures.



Watercolor reconstruction of the Pylos Throne Room by Piet de Jong. (Credit: Courtesy of the Department of Classics, University of Cincinnati)

In researching one such floor in the Throne Room at the Palace of Nestor, one of the best-preserved palaces of the Mycenaean civilization, University of Cincinnati Department of Classics doctoral student Emily Catherine Egan has found evidence that the floor's painted designs, dating back to between 1300-1200 BC, were meant to replicate a physical hybrid of cloth and stone -- serving not only to impress but also to instruct the ancient viewer.

She will present her findings at the Annual Meeting of the Archaeological Institute of America, Jan. 2-5, in Chicago, one of a number of UC presentations at the conference. Her work at the Palace of Nestor builds on a long tradition in UC's McMicken College of Arts and Sciences since the remains of the site were first discovered in 1939 by UC archaeologist Carl Blegen.

According to Egan, "Mycenaean palatial floor paintings are typically believed to represent a single surface treatment -- most often cut stone or pieced carpets. At Pylos, however, the range of represented patterns suggests that the floor in the great hall of the palace was deliberately designed to represent both of these materials simultaneously, creating a new, clever way to impress visitors while simultaneously instructing them on where to look and how to move within the space."

As part of her work with UC's Hora Apotheke Reorganization Project (HARP), Egan conducted research on the painted floor at the Palace of Nestor from 2012-13. She examined firsthand sections of the floor, as well as published and unpublished excavation documents and drawings.

During her research, Egan noted that some of the intricate motifs of the Throne Room floor recalled the mottled and veined patterns of painted stone masonry, while other elements mimicked patterns on depictions of textiles in wall paintings both from Crete and the Greek mainland.

She contended that the hybrid combination of these materials on the Throne Room floor (also evident in other paintings in the palace) was specifically designed to "supersede reality. It depicted something that could not exist in the real world, a floor made of both carpet and stone. As such, the painting would have communicated the immense, and potentially supernatural power of the reigning monarch, who seemingly had the ability to manipulate and transform his physical environment."

Egan also argued that the hybrid quality of the floor was intended to draw attention to one of its other notable features -- a dramatic diagonal in the grid design, apparent upon standing at the doorway of the room. Past studies had posited that this introduction of a strong diagonal into the floor's otherwise regular grid pattern had been an uncorrected mistake.

However, Egan's firsthand examination of parts of the floor found evidence that small mistakes on individual painted tiles had been corrected by the ancient artists. Thus, she reasoned, "Since they corrected such small mistakes, it seems highly unlikely that those same artists would have left a major error, like misaligning a large portion of the room's floor, uncorrected. Instead, I believe that the diagonal was intentional -- a way to draw both a visitor's eyes and his or her footsteps toward the throne positioned along the right-hand wall of the room. It was painting with a purpose."

In addition, Egan's study at the Palace of Nestor has uncovered the first evidence for the use of a drafting technique called an artist's grid to paint a floor. Until now, artists' grids have only been identified in Bronze Age wall paintings, almost all of them from Crete. (An artist's grid is just that, a faint grid laid down on a surface to be painted in order to subdivide that surface and aid in breaking down and accurately spacing a complex, repeating pattern or design.)

According to Egan, "A fragment of wall painting from Pylos shows evidence of the use of an artist's grid, and nine squares of the Throne Room's floor feature the same technique. As on walls, the floor grids were used to create a range of sophisticated, balanced designs -- only this time on a horizontal rather than vertical canvas. This find is particularly exciting because it solves a longstanding riddle. When first excavated, these 'mini grids' were tentatively identified as functional elements of the room -- marking out places for dignitaries to stand on occasions of state. My re-study of the grids, however, now shows that they were artists' tools, providing us with important new information about how the painted floor was designed and constructed."

Monday, January 6, 2014

4.4 million-year-old African species Ardipithecus ramidus is related to the human lineage


One of the most hotly debated issues in current human origins research focuses on how the 4.4 million-year-old African species Ardipithecus ramidus is related to the human lineage. "Ardi" was an unusual primate. Though it possessed a tiny brain and a grasping big toe used for clambering in the trees, it had small, humanlike canine teeth and an upper pelvis modified for bipedal walking on the ground.

Scientists disagree about where this mixture of features positions Ardipithecus ramidus on the tree of human and ape relationships. Was Ardi an ape with a few humanlike features retained from an ancestor near in time (6 and 8 million years ago, according to DNA evidence) to the split between the chimpanzee and human lines? Or was it a true relative of the human line that had yet to shed many signs of its remote tree-dwelling ancestry?

New research led by ASU paleoanthropologist William Kimbel confirms Ardi's close evolutionary relationship to humans. Kimbel and his collaborators turned to the underside (or base) of a beautifully preserved partial cranium of Ardi. Their study revealed a pattern of similarity that links Ardi to Australopithecus and modern humans and but not to apes.

The research appears in the January 6, 2014, online edition of Proceedings of the National Academy of Science. Kimbel is director of the ASU Institute of Human Origins, a research center of the College of Liberal Arts and Sciences in the School of Human Evolution and Social Change. Joining ASU's Kimbel as co-authors are Gen Suwa (University of Tokyo Museum), Berhane Asfaw (Rift Valley Research Service, Addis Ababa), Yoel Rak (Tel Aviv University), and Tim White (University of California at Berkeley).

White's field-research team has been recovering fossil remains of Ardipithecus ramidus in the Middle Awash Research area, Ethiopia, since the 1990s. The most recent study of the Ardi skull, led by Suwa, was published in Science in 2009, whose work (with the Middle Awash team) first revealed humanlike aspects of its base. Kimbel co-leads the team that recovered the earliest known Australopithecus skulls from the Hadar site, home of the "Lucy" skeleton, in Ethiopia.

"Given the very tiny size of the Ardi skull, the similarity of its cranial base to a human's is astonishing," says Kimbel.

The cranial base is a valuable resource for studying phylogenetic, or natural evolutionary relationships, because its anatomical complexity and association with the brain, posture, and chewing system have provided numerous opportunities for adaptive evolution over time. The human cranial base, accordingly, differs profoundly from that of apes and other primates.

In humans, the structures marking the articulation of the spine with the skull are more forwardly located than in apes, the base is shorter from front to back, and the openings on each side for passage of blood vessels and nerves are more widely separated.

These shape differences affect the way the bones are arranged on the skull base such that it is fairly easy to tell apart even isolated fragments of ape and human basicrania.

Ardi's cranial base shows the distinguishing features that separate humans and Australopithecus from the apes. Kimbel's earlier research (with collaborator Rak) had shown that these human peculiarities were present in the earliest known Australopithecus skulls by 3.4 million years ago.

The new work expands the catalogue of anatomical similarities linking humans, Australopithecus, and Ardipithecus on the tree of life and shows that the human cranial base pattern is at least a million years older than Lucy's species, A. afarensis.

Paleoanthropologists generally fall into one of two camps on the cause of evolutionary changes in the human cranial base. Was it the adoption of upright posture and bipedality causing a shift in the poise of the head on the vertebral column? If so, does the humanlike cranial base of Ar. ramidus confirm postcranial evidence for partial bipedality in this species? Or, do the changes tell us about the shape of the brain (and of the base on which it sits), perhaps an early sign of brain reorganization in the human lineage? Both alternatives will need to be re-evaluated in light of the finding that Ardi does indeed appear to be more closely related to humans than to chimpanzees.

"The Ardi cranial base fills some important gaps in our understanding of human evolution above the neck," adds Kimbel. "But it opens up a host of new questions…just as it should!"