Thursday, September 30, 2010

No evidence for Clovis comet catastrophe, archaeologists say

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New research challenges the controversial theory that an ancient comet impact devastated the Clovis people, one of the earliest known cultures to inhabit North America.

Writing in the October issue of Current Anthropology, archaeologists Vance Holliday (University of Arizona) and David Meltzer (Southern Methodist University) argue that there is nothing in the archaeological record to suggest an abrupt collapse of Clovis populations. "Whether or not the proposed extraterrestrial impact occurred is a matter for empirical testing in the geological record," the researchers write. "Insofar as concerns the archaeological record, an extraterrestrial impact is an unnecessary solution for an archaeological problem that does not exist."

The comet theory first emerged in 2007 when a team of scientists announced evidence of a large extraterrestrial impact that occurred about 12,900 years ago. The impact was said to have caused a sudden cooling of the North American climate, killing off mammoths and other megafauna. It could also explain the apparent disappearance of the Clovis people, whose characteristic spear points vanish from the archaeological record shortly after the supposed impact.

As evidence for the rapid Clovis depopulation, comet theorists point out that very few Clovis archaeological sites show evidence of human occupation after the Clovis. At the few sites that do, Clovis and post-Clovis artifacts are separated by archaeologically sterile layers of sediments, indicating a time gap between the civilizations. In fact, comet theorists argue, there seems to be a dead zone in the human archaeological record in North America beginning with the comet impact and lasting about 500 years.





These are Clovis Points.





But Holliday and Meltzer dispute those claims. They argue that a lack of later human occupation at Clovis sites is no reason to assume a population collapse. "Single-occupation Paleoindian sites—Clovis or post-Clovis—are the norm," Holliday said. That's because many Paleoindian sites are hunting kill sites, and it would be highly unlikely for kills to be made repeatedly in the exact same spot.

"So there is nothing surprising about a Clovis occupation with no other Paleoindian zone above it, and it is no reason to infer a disaster," Holliday said.

In addition, Holliday and Meltzer compiled radiocarbon dates of 44 archaeological sites from across the U.S. and found no evidence of a post-comet gap. "Chronological gaps appear in the sequence only if one ignores standard deviations (a statistically inappropriate procedure), and doing so creates gaps not just around [12,900 years ago] but also at many later points in time," they write.

Sterile layers separating occupation zones at some sites are easily explained by shifting settlement patterns and local geological processes, the researchers say. The separation should not be taken as evidence of an actual time gap between Clovis and post-Clovis cultures.

Holliday and Meltzer believe that the disappearance of Clovis spear points is more likely the result of a cultural choice rather than a population collapse. "There is no compelling data to indicate that North American Paleoindians had to cope with or were affected by a catastrophe, extraterrestrial or otherwise, in the terminal Pleistocene," they conclude.

Saturday, September 25, 2010

Construction Secrets of Ancient Egypt's Pyramids

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Scientists from around the world have tried to understand how the Egyptians erected their giant pyramids. Now, an architect and researcher at the Norwegian University of Science and Technology (NTNU) says he has the answer to this ancient, unsolved puzzle.

Researchers have been so preoccupied by the weight of the stones that they tend to overlook two major problems: How did the Egyptians know exactly where to put the enormously heavy building blocks? And how was the master architect able to communicate detailed, highly precise plans to a workforce of 10,000 illiterate men?

A 7-million-ton structure

These were among the questions that confronted Ole J. Bryn, an architect and associate professor in NTNU's Faculty of Architecture and Fine Art when he began examining Khufu's Great Pyramid in Giza. Khufu's pyramid, better known as the Pyramid of Cheops, consists of 2.3 million limestone blocks weighing roughly 7 million tons. At 146.6 meters high, it held the record as the tallest structure ever built for nearly 4000 years.

What Bryn discovered was quite simple. He believes that the Egyptians invented the modern building grid, by separating the structure's measuring system from the physical building itself, thus introducing tolerance, as it is called in today's engineering and architectural professions.

The apex point a key

Bryn has studied the plans from the thirty oldest Egyptian pyramids, and discovered a precision system that made it possible for the Egyptians to reach the pyramid's last and highest point, the apex point, with an impressive degree of accuracy. By exploring and making a plan of the pyramid it is possible to prepare modern project documentation of not just one, but all pyramids from any given period.

As long as the architect knows the main dimensions of a pyramid, he can project the building as he would have done it with a modern building, but with building methods and measurements known from the ancient Egypt, Bryn says.

In a scientific article published May 2010 in the Nordic Journal of Architectural Research, Bryn discusses aspects that can explain the construction of a multitude of the Egyptian pyramids by taking the building grid, and not the physical building itself, as the starting point for the analysis.

A new map

If the principles behind Bryn's drawings are correct, then archaeologists will have a new "map" that demonstrates that the pyramids are not a "bunch of heavy rocks with unknown structures" but, rather, incredibly precise structures.

Ole J. Bryn's findings will be presented and explained at the exhibition The Apex Point in Trondheim from September 13th to October 1st. The exhibition is an official part of the program to celebrate the centenary (1910-2010) of the Norwegian University of Science and Technology.

About the author:

Ole J. Bryn is a former practising architect, and currently holds a position as Associate Professor at the Faculty of Architecture and Fine Art, the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway.

The development of Bryn's theories on the building grids used in Egyptian pyramids has benefited from cooperation with Dr. Michel Barsoum, Grosvenor and Distinguished Professor at the Department of Materials Science and Engineering, Drexel University, Philadelphia.

Thursday, September 23, 2010

Neanderthals More Advanced Than Previously Thought: They Innovated, Adapted Like Modern Humans

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For decades scientists believed Neanderthals developed `modern' tools and ornaments solely through contact with Homo sapiens, but new research from the University of Colorado Denver now shows these sturdy ancients could adapt, innovate and evolve technology on their own.

The findings by anthropologist Julien Riel-Salvatore challenge a half-century of conventional wisdom maintaining that Neanderthals were thick-skulled, primitive `cavemen' overrun and outcompeted by more advanced modern humans arriving in Europe from Africa.

"Basically, I am rehabilitating Neanderthals," said Riel-Salvatore, assistant professor of anthropology at UC Denver. "They were far more resourceful than we have given them credit for."

His research, to be published in December's Journal of Archaeological Method and Theory, was based on seven years of studying Neanderthal sites throughout Italy, with special focus on the vanished Uluzzian culture.

About 42,000 years ago, the Aurignacian culture, attributed to modern Homo sapiens, appeared in northern Italy while central Italy continued to be occupied by Neanderthals of the Mousterian culture which had been around for at least 100,000 years. At this time a new culture arose in the south, one also thought to be created by Neanderthals. They were the Uluzzian and they were very different.

Riel-Salvatore identified projectile points, ochre, bone tools, ornaments and possible evidence of fishing and small game hunting at Uluzzian archeological sites throughout southern Italy. Such innovations are not traditionally associated with Neanderthals, strongly suggesting that they evolved independently, possibly due to dramatic changes in climate. More importantly, they emerged in an area geographically separated from modern humans.

"My conclusion is that if the Uluzzian is a Neanderthal culture it suggests that contacts with modern humans are not necessary to explain the origin of this new behavior. This stands in contrast to the ideas of the past 50 years that Neanderthals had to be acculturated to humans to come up with this technology," he said. "When we show Neanderthals could innovate on their own it casts them in a new light. It `humanizes' them if you will."

Thousands of years ago, southern Italy experienced a shift in climate, becoming increasingly open and arid, said Riel-Salvatore. Neanderthals living there faced a stark choice of adapting or dying out. The evidence suggests they began using darts or arrows to hunt smaller game to supplement the increasingly scarce larger mammals they traditionally hunted.

"The fact that Neanderthals could adapt to new conditions and innovate shows they are culturally similar to us," he said. "Biologically they are also similar. I believe they were a subspecies of human but not a different species."

The powerfully built Neanderthals were first discovered in Germany's Neander Valley in 1856. Exactly who they were, how they lived and why they vanished remains unclear.

Research shows they contributed between 1 and 4 percent of their genetic material to the people of Asia and Europe. Riel-Salvatore rejects the theory that they were exterminated by modern humans. Homo sapiens might simply have existed in larger groups and had slightly higher birthrates, he said.

"It is likely that Neanderthals were absorbed by modern humans," he said. "My research suggests that they were a different kind of human, but humans nonetheless. We are more brothers than distant cousins."

Tuesday, September 21, 2010

Applying Physics to Red Sea Escape Route

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The biblical account of the parting of the Red Sea has inspired and mystified people for millennia. A new computer modeling study by researchers at the National Center for Atmospheric Research (NCAR) and the University of Colorado at Boulder (CU) shows how the movement of wind as described in the book of Exodus could have parted the waters.

The computer simulations show that a strong east wind, blowing overnight, could have pushed water back at a bend where an ancient river is believed to have merged with a coastal lagoon along the Mediterranean Sea. With the water pushed back into both waterways, a land bridge would have opened at the bend, enabling people to walk across exposed mud flats to safety. As soon as the wind died down, the waters would have rushed back in.



The study is intended to present a possible scenario of events that are said to have taken place more than 3,000 years ago, although experts are uncertain whether they actually occurred. The research was based on a reconstruction of the likely locations and depths of Nile delta waterways, which have shifted considerably over time.

"The simulations match fairly closely with the account in Exodus," says Carl Drews of NCAR, the lead author. "The parting of the waters can be understood through fluid dynamics. The wind moves the water in a way that's in accordance with physical laws, creating a safe passage with water on two sides and then abruptly allowing the water to rush back in."

The study is part of a larger research project by Drews into the impacts of winds on water depths, including the extent to which Pacific Ocean typhoons can drive storm surges. By pinpointing a possible site south of the Mediterranean Sea for the crossing, the study also could be of benefit to experts seeking to research whether such an event ever took place. Archeologists and Egyptologists have found little direct evidence to substantiate many of the events described in Exodus.

The work, published in the online journal, PLoS ONE, arose out of Drews' master's thesis in atmospheric and oceanic sciences at CU. The computing time and other resources were supported by the National Science Foundation.

-----Wind on the water -----

The Exodus account describes Moses and the fleeing Israelites trapped between the Pharaoh's advancing chariots and a body of water that has been variously translated as the Red Sea or the Sea of Reeds. In a divine miracle, the account continues, a mighty east wind blows all night, splitting the waters and leaving a passage of dry land with walls of water on both sides. The Israelites are able to flee to the other shore. But when the Pharaoh's army attempts to pursue them in the morning, the waters rush back and drown the soldiers.

Scientists from time to time have tried to study whether the parting of the waters, one of the famous miracles in the Bible, can also be understood through natural processes. Some have speculated about a tsunami, which would have caused waters to retreat and advance rapidly. But such an event would not have caused the gradual overnight divide of the waters as described in the Bible, nor would it necessarily have been associated with winds.

Other researchers have focused on a phenomenon known as "wind setdown," in which a particularly strong and persistent wind can lower water levels in one area while piling up water downwind. Wind setdowns, which are the opposite of storm surges, have been widely documented, including an event in the Nile delta in the 19th century when a powerful wind pushed away about five feet of water and exposed dry land.

A previous computer modeling study into the Red Sea crossing by a pair of Russian researchers, Naum Voltzinger and Alexei Androsov, found that winds blowing from the northwest at minimal hurricane force (74 miles per hour) could, in theory, have exposed an underwater reef near the modern-day Suez Canal. This would have enabled people to walk across. The Russian study built on earlier work by oceanographers Doron Nof of Florida State University and Nathan Paldor of Hebrew University of Jerusalem that looked at the possible role of wind setdown.

The new study, by Drews and CU oceanographer Weiqing Han, found that a reef would have had to be entirely flat for the water to drain off in 12 hours. A more realistic reef with lower and deeper sections would have retained channels that would have been difficult to wade through. In addition, Drews and Han were skeptical that refugees could have crossed during nearly hurricane-force winds.

-----Reconstructing ancient topography-----

Studying maps of the ancient topography of the Nile delta, the researchers found an alternative site for the crossing about 75 miles north of the Suez reef and just south of the Mediterranean Sea. Although there are uncertainties about the waterways of the time, some oceanographers believe that an ancient branch of the Nile River flowed into a coastal lagoon then known as the Lake of Tanis. The two waterways would have come together to form a U-shaped curve.

An extensive analysis of archeological records, satellite measurements, and current-day maps enabled the research team to estimate the water flow and depth that may have existed 3,000 years ago. Drews and Han then used a specialized ocean computer model to simulate the impact of an overnight wind at that site.

They found that a wind of 63 miles an hour, lasting for 12 hours, would have pushed back waters estimated to be six feet deep. This would have exposed mud flats for four hours, creating a dry passage about 2 to 2.5 miles long and 3 miles wide. The water would be pushed back into both the lake and the channel of the river, creating barriers of water on both sides of newly exposed mud flats.

As soon as the winds stopped, the waters would come rushing back, much like a tidal bore. Anyone still on the mud flats would be at risk of drowning.

The set of 14 computer model simulations also showed that dry land could have been exposed in two nearby sites during a windstorm from the east. However, those sites contained only a single body of water and the wind would have pushed the water to one side rather than creating a dry passage through two areas of water.

"People have always been fascinated by this Exodus story, wondering if it comes from historical facts," Drews says. "What this study shows is that the description of the waters parting indeed has a basis in physical laws."

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Thursday, September 16, 2010

Goddess of Fortune found at Sussita

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A wall painting (fresco) of Tyche, the Greek goddess of fortune, was exposed during the 11th season of excavation at the Sussita site, on the east shore of the Sea of Galilee, which was conducted by researchers of the University of Haifa.



Head of Tyche, goddess of fortune, on the fresco


Another female figure was found during this season, of a maenad, one of the companions of the wine god Dionysus.



Maenad figurine


“It is interesting to see that although the private residence in which two goddesses were found was in existence during the Byzantine period, when Christianity negated and eradicated idolatrous cults, one can still find clear evidence of earlier beliefs,” said Prof. Arthur Segal and Dr. Michael Eisenberg of the Zinman Institute of Archaeology at the University of Haifa, who headed the excavation.

The city of Sussita is located within the Sussita National Park under the management of the Israel Nature and Parks Authority, which has accompanied and assisted the excavation teams this season in enabling the continuation of excavation work and the conservation of the archaeological finds.

During the course of the excavations conducted by the team from the University of Concordia under the direction of Prof. Mark Schuler, in a residence that appeared, by the quality and complexity of its construction, to belong to one of the city notables, the excavators reached an inner courtyard with a small fountain at its center. Near the fountain they found a fresco of Tyche, who was apparently deified as the city’s goddess of fortune. Her head is crowned, her youthful gaze is focused, and she has abundant brown hair beneath her crown. According to the researchers, artistic analysis has indicated that the wall painting may be dated to the end of the Roman period or the beginning of the Byzantine period (3rd-4th centuries C.E.).

The goddess Tyche was not the only mythological figure to be discovered in this compound. Found on a bone plate was a wonderfully etched relief of a maenad, one of a group of female followers of Dionysus, the god of wine. According to Greek mythology, the maenads accompanied Dionysus with frenzied dances while holding a thyrsus, a device symbolizing sexuality, fertility, and the male sexual organ associated with sexual pleasure. The maenad of Sussita was also depicted as being in the midst of a frenzied dance. The researchers believe that both manifestations of the cult of Graeco-Roman female goddesses can be dated to the end of the Roman period, but there is no doubt that the residence in which they were found continued to exist even after Christianity triumphed over idolatry.

In this season the city’s Roman period basilica (1st-2nd centuries CE) began to be exposed. This is a large-sized building that incorporated the city’s central commercial, social and judicial areas. Besides the excellent architectural marble items that were unearthed there, the researchers also found decorations made of “stucco”, molded plaster used in the imitation of marble. “We could not fail to wonder how a relatively plebeian city could employ first-class builders and artisans. The stucco decorations demonstrate that despite everything, the city rulers were certainly not sparing of the costs and expenditure of construction,” the researchers noted.

Sussita was erected on a mountain top rising to the east of the Sea of Galilee during the 2nd century B.C.E. by the Seleucid rulers who then controlled the country. The city existed during the Hellenist, Roman, Byzantine and Umayyad periods, until it was destroyed by a violent earthquake in the year 749 C.E. Together with Beth Shean and other cities on the eastern bank of the Jordan River, Sussita was one of the cultural-geographical group of Decapolis cities - a region within which Jesus conducted some of the miracles described in the New Testament.

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Friday, September 3, 2010

From Israel: Evidence of Organized Feasting by Early Humans

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Community feasting is one of the most universal and important social behaviors found among humans. Now, scientists have found the earliest clear evidence of organized feasting, from a burial site dated about 12,000 years ago. These remains represent the first archaeological verification that human feasting began before the advent of agriculture.


This is a view of excavation area at Hilazon Tachtit Cave, Israel. (Credit: Naftali Hilger)

"Scientists have speculated that feasting began before the Neolithic period, which starts about 11.5 thousand years ago," says Natalie Munro of the University of Connecticut, and author of a research article in the Proceedings of the National Academy of Sciences. "This is the first solid evidence that supports the idea that communal feasts were already occurring -- perhaps with some frequency -- at the beginnings of the transition to agriculture."

At a burial cave in the Galilee region of northern Israel, Munro and her colleague Leore Grosman of Hebrew University in Jerusalem uncovered the remains of at least 71 tortoises and three wild cattle in two specifically crafted hollows, an unusually high density for the period. The tortoise shells and cattle bones exhibited evidence of being cooked and torn apart, indicating that the animals had been butchered for human consumption.

Each of the two hollows, says Munro, was manufactured for the purpose of a ritual human burial and related feasting activities. The tortoise shells were situated under, around and on top of the remains of a ritually-buried shaman, which suggests that the feast occurred concurrently with the ritual burial. On their own, the meat from the discarded tortoise shells could probably have fed about 35 people, says Munro, but it's possible that many more than that attended this feast.

"We don't know exactly how many people attended this particular feast, or what the average attendance was at similar events, since we don't know how much meat was actually available in the cave," says Munro. "The best we can do is give a minimum estimate based on the bones that are present."

A major reason why humans began feasting -- and later began to cultivate their own foods -- is because faster human population growth had begun to crowd their landscape. In earlier periods of the Stone Age, says Munro, small family groups were often on the move to find new sources of food. But around the time of this feast, she says, that lifestyle had become much more difficult.

"People were coming into contact with each other a lot, and that can create friction," she says. "Before, they could get up and leave when they had problems with the neighbors. Now, these public events served as community-building opportunities, which helped to relieve tensions and solidify social relationships."

But when a once-nomadic group of humans settles down, that can put tremendous pressure on the local resources. Munro notes that humans around the time of this feast were intensively using the plants and animals that their descendants later domesticated.

"The appearance of these feasts at the beginnings of agriculture is particularly interesting because people are starting to experiment with domestication and cultivation," she notes.

This combination of increased social interaction and changes in resources, says Munro, is what eventually led to the beginnings of agriculture.

"Taken together, this community integration and the changes in economics were happening at the very beginning when incipient cultivation was getting going," she says. "These kinds of social changes are the beginnings of significant changes in human social complexity that lead into the beginning of the agricultural transition."

Thursday, September 2, 2010

Ancient brewers tapped antibiotic secrets

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A chemical analysis of the bones of ancient Nubians shows that they were regularly consuming tetracycline, most likely in their beer. The finding is the strongest evidence yet that the art of making antibiotics, which officially dates to the discovery of penicillin in 1928, was common practice nearly 2,000 years ago.

The research, led by Emory anthropologist George Armelagos and medicinal chemist Mark Nelson of Paratek Pharmaceuticals, Inc., is published in the American Journal of Physical Anthropology.

“We tend to associate drugs that cure diseases with modern medicine,” Armelagos says. “But it’s becoming increasingly clear that this prehistoric population was using empirical evidence to develop therapeutic agents. I have no doubt that they knew what they were doing.”

Armelagos is a bioarcheologist and an expert on prehistoric and ancient diets. In 1980, he discovered what appeared to be traces of tetracycline in human bones from Nubia dated between A.D. 350 and 550, populations that left no written record. The ancient Nubian kingdom was located in present-day Sudan, south of ancient Egypt.
Green fluorescence in Nubian skeletons indicated tetracycline-labeled bone, the first clue that the ancients were producing the antibiotic.

Armelagos and his fellow researchers later tied the source of the antibiotic to the Nubian beer. The grain used to make the fermented gruel contained the soil bacteria streptomyces, which produces tetracycline. A key question was whether only occasional batches of the ancient beer contained tetracycline, which would indicate accidental contamination with the bacteria.

Nelson, a leading expert in tetracycline and other antibiotics, became interested in the project after hearing Armelagos speak at a conference. “I told him to send me some mummy bones, because I had the tools and the expertise to extract the tetracycline,” Nelson says. “It’s a nasty and dangerous process. I had to dissolve the bones in hydrogen fluoride, the most dangerous acid on the planet.”

The results stunned Nelson. “The bones of these ancient people were saturated with tetracycline, showing that they had been taking it for a long time,” he says. “I’m convinced that they had the science of fermentation under control and were purposely producing the drug.”

Even the tibia and skull belonging to a 4-year-old were full of tetracycline, suggesting that they were giving high doses to the child to try and cure him of illness, Nelson says.

The first of the modern day tetracyclines was discovered in 1948. It was given the name auereomycin, after the Latin word “aerous,” which means containing gold. “Streptomyces produce a golden colony of bacteria, and if it was floating on a batch of beer, it must have look pretty impressive to ancient people who revered gold,” Nelson theorizes.

The ancient Egyptians and Jordanians used beer to treat gum disease and other ailments, Armelagos says, adding that the complex art of fermenting antibiotics was probably widespread in ancient times, and handed down through generations.

The chemical confirmation of tetracycline in ancient bones is not the end of the story for Armelagos. He remains enthused after more than three decades on the project. “This opens up a whole new area of research,” he says. “Now we’re going to compare the amount of tetracycline in the bones, and bone formation over time, to determine the dosage that the ancient Nubians were getting.”