Tuesday, May 22, 2012

2,000-year-old stone anchor offers clues to Indo-Arab trade

Scientists of the National Institute of Oceanography (NIO) have found an Indo-Arabic stone anchor off the Kutch coast in Gujarat that offers significant clues to the Indo-Arabic and Indo-Persian trade of the first and second century B.C. It was found at a depth of more than 50 metres. The find has been published in the May issue of scientific journal "Current Science". "Ancient stone anchors serve to understand maritime contacts of India with other parts of the world... Arabs and Persians sailed the Indian Ocean and used the type of anchors under study since the 9th century. Indo-Arabian type stone anchors have been reported from the western Indian Ocean countries, namely east Africa, India, Persian Gulf countries and Sri lanka, suggesting close maritime contacts and trade relations among these countries. "The ports in the Gulf of Kachchh have contributed significantly to maritime trade since ancient times, and such trade was extensive between Gujarat and the Arab world even during the medieval period," the study reported. The antique broke into two pieces while being retrieved. "While the anchor was being retrieved, it fell from the dredger and broke into two pieces along a fracture plane that developed 70 cm below the upper circular hole," the study reported. Sila Tripathi, a marine archaeologist at the NIO who studied the anchor said more studies needed to be done to determine the exact source of the rock material. Tripathi said it was most likely of Indian origin. "More studies need to be done to know where it came from, which includes studying the nature of rock along the entire Western Indian coastline to find a match," he said. "Further comparative studies of epiclastic rocks from these areas are required to verify whether the stone anchor reported in this study could have been made from one of these rocks. An earlier study showed that stone anchors recovery from Indian waters are made of rocks found along the Indian coast. "As there are no associated finds along with the stone anchor in the present study, it is difficult to determine the exact age. However, on the basis of comparative analysis, similar type of Indo-Arabian-type of stone anchors have been dated between 9th and 17th century AD in the Indian waters," Tripathi said in his paper. The anchor stone is composed of quartz and feldspar grains floating in a ferruginous matrix. "No anchors have been reported so far from the northern coast of the Gulf of Kachchh. Further, the stone anchors reported from Gujarat or elsewhere in India are primarily from ports and harbour sites, sheltered bays and shipwreck sites. The anchor reported in this study has been found in none of the above described contexts. Very little is known about the finding of stone anchors in waters deeper than 20 m along the Indian Coast. "Recovery of a stone anchor from deeper water is a unique find where the seabed is thickly sedimented especially like the Gulf of Kachchh. This is the first stone anchor that has been found in the northern part of the Gulf of Kachchh at a depth greater than 50 m," the study reported. Maritime archaeological exploration in India has brought out a variety of stone anchors from Gujarat, Maharashtra, Goa, Kerala and Lakshadweep on the west coast, and Tamil Nadu and Odisha along the east coast. In recent years, 16 stone anchors consisting of Indo-Arabian, ring stone and single-hole types were discovered from Goa and Gujarat waters.

Tuesday, March 27, 2012

'Red Deer Cave people' may be new species of human

(Source: The Gurdian)
The fossilised remains of stone age people recovered from two caves in south west China may belong to a new species of human that survived until around the dawn of agriculture.

The partial skulls and other bone fragments, which are from at least four individuals and are between 14,300 and 11,500 years old, have an extraordinary mix of primitive and modern anatomical features that stunned the researchers who found them.

Named the Red Deer Cave people, after their apparent penchant for home-cooked venison, they are the most recent human remains found anywhere in the world that do not closely resemble modern humans.

The individuals differ from modern humans in their jutting jaws, large molar teeth, prominent brows, thick skulls, flat faces and broad noses. Their brains were of average size by ice age standards.

"They could be a new evolutionary line or a previously unknown modern human population that arrived early from Africa and failed to contribute genetically to living east Asians," said Darren Curnoe, who led the research team at the University of New South Wales in Australia.

"While finely balanced, I think the evidence is slightly weighted towards the Red Deer Cave people representing a new evolutionary line. First, their skulls are anatomically unique. They look very different to all modern humans, whether alive today or in Africa 150,000 years ago," Curnoe told the Guardian.

"Second, the very fact they persisted until almost 11,000 years ago, when we know that very modern looking people lived at the same time immediately to the east and south, suggests they must have been isolated from them. We might infer from this isolation that they either didn't interbreed or did so in a limited way."

One partial skeleton, with much of the skull and teeth, and some rib and limb bones, was recovered from Longlin cave in Guangxi province. More than 30 bones, including at least three partial skulls, two lower jaws and some teeth, ribs and limb fragments, were unearthed at nearby Maludong, or Red Deer Cave, near the city of Mengzi in Yunnan province.

At Maludong, fossil hunters also found remnants of various mammals, all of them species still around today, except for giant red deer, the remains of which were found in abundance. "They clearly had a taste for venison, with evidence they cooked these large deer in the cave," Curnoe said.

The findings are reported in the journal PLoS ONE.

The stone age bones are particularly important because scientists have few human fossils from Asia that are well described and reliably dated, making the story of the peopling of Asia hopelessly vague. The latest findings point to a far more complex picture of human evolution than was previously thought.

"The discovery of the Red Deer Cave people shows just how complicated and interesting human evolutionary history was in Asia right at the end of the ice age. We had multiple populations living in the area, probably representing different evolutionary lines: the Red Deer Cave people on the East Asian continent, Homo floresiensis, or the 'Hobbit', on the island of Flores in Indonesia, and modern humans widely dispersed from northeast Asia to Australia. This paints an amazing picture of diversity, one we had no clue about until this last decade," Curnoe said.

Much of Asia was also occupied by Neanderthals and another group of archaic humans called the Denisovans. Scientists learned of the Denisovans after recovering a fossilised little finger from the Denisova cave in the Altai mountains of southern Siberia in 2010.

The fossils from Longlin cave were found in 1979 by a geologist prospecting in the area. At the time, researchers removed only the lower jaw and a few fragments of rib and limb bones from the cave wall. The rest of the skeleton was left encased in a block of rock, which sat in the basement of the Yunnan Institute of Cultural Relics and Archaeology in Kunming, Yunnan, for 30 years. The fossils were rediscovered in 2009 by Ji Xueping, a researcher at the institute, who teamed up with Curnoe to examine the remains.

"It was clear from what we could see that the remains were very primitive and likely to be scientifically important. We had a skilled technician remove the bones from the rock, and they were glued back together. Only then was it clear what we had found: a partial skeleton with a very unusual anatomy," Curnoe said.

The fossils at Maludong were found in 1989 but went unstudied until 2008.

Lumps of charcoal uncovered alongside the Longlin fossils were carbon dated to 11,500 years, a time when modern humans in southern China began to make pottery for food storage and to gather wild rice in some of the first steps towards full-scale farming.

Marta Mirazón Lahr, an evolutionary biologist at Cambridge University, is convinced the remains are from modern humans. The unusual features, she said, suggest the Red Deer Cave people are either "late descendants of an early population of modern humans in Asia" or a very small population that developed the traits through a process known as genetic drift.

Chris Stringer, head of human origins at the Natural History Museum, London, was similarly sceptical.

"The human remains from the Longlin Cave and Maludong are very important, particularly because we do not have much well-described and well-dated material from the late Pleistocene of China.

"The fossils are unlike recent populations of modern humans in several respects, and the mosaic of more archaic features could indicate the dispersal of a poorly known and more primitive form of modern human that left Africa before the main exodus at about 60,000 years. This dispersal could have reached as far as China, surviving there for many millennia, before disappearing in the last 12,000 years."

But he added: "There might be another possible explanation for the more archaic features. Could these alternatively be attributed to gene flow from a more archaic population that survived alongside modern humans? In the case of the Longlin Cave and Maludong fossils, the most likely candidate would be the enigmatic Denisovans who apparently interbred with the ancestors of modern Australasians somewhere in south east Asia. Could these Chinese fossils be further evidence of such hybridisation?"

Friday, August 6, 2010

Britain secret file says massive UFO spotted

A spaceship that was "20 times the size of a football field" was spotted hovering over Britain's Manchester airport nearly 15 years back, says a secret defence ministry file that was released today.

The huge spacecraft was seen by a UFO expert in 1995 and its sketch was sent to the defence ministry, The Sun reported today, citing the secret files.

The UFO was described as oblong with a curved front and a series of small nozzles at the rear.

That's not the only UFO sighting.

A "cigar-shaped" object was seen over Lancashire in 1977 and a "strange, glowing object" was spotted near RAF Woodbridge, Suffolk, in 1980.

In 1998, a circular "space station" was seen in Gwent, South Wales.

"A proportion of sightings could not be explained," Nick Pope, who worked on the files, was quoted as saying.

Wednesday, October 7, 2009

A high-tech hunt for a lost Leonardo

Expert Uses Lasers, Neutrons To Uncover Da Vinci’s Largest Masterpiece, Hidden Inside A Wall

John Tierney

Florence, Italy: If you believe, as Maurizio Seracini does, that Leonardo da Vinci’s greatest painting is hidden inside a wall in Florence’s city hall, then there are two essential techniques for finding it.

First, concentrate on scientific gadgetry. After spotting what seemed to be a clue to Leonardo’s painting left by another 16th-century artist, Seracini led experts in mapping every millimeter of the wall with lasers, radar, ultraviolet light and infrared cameras. Once they identified the place, they developed devices to detect the painting by firing neutrons into the wall.

Seracini was standing in the Palazzo Vecchio’s grand ceremonial chamber, the Hall of 500, which was the center of Renaissance politics when Leonardo and Michelangelo were commissioned to adorn it with murals of Florentine military victories. In 2009, it remained the political hub, as evidenced by the sudden appearance of Florence’s new mayor Matteo Renzi.

The scientific lecture ceased as Seracini moved quickly to intercept the mayoral entourage. He was eager to use the second essential strategy for retrieving a Leonardo painting in Florence: find the right patron.

Seracini, an engineering professor at the University of California, San Diego, had spent years in bureaucratic limbo waiting to try his neutron-beam technique, but he saw this new mayor as his best hope yet.

The quest had begun more than three decades earlier. In 1975, after studying engineering in the US, Seracini returned to his native Florence and surveyed the Hall of 500. He was looking for “The Battle of Anghiari”, the largest painting Leonardo ever undertook (three times the width of “The Last Supper”). Although it was never completed, he left a central scene of clashing soldiers and horses that was hailed as an unprecedented study of anatomy and motion.

Then it vanished. During the remodeling of the hall in 1563, the architect and painter Giorgio Vasari covered the walls with frescoes of military victories by the Medicis.

But in 1975, when Seracini studied one of Vasari’s battle scenes, he noticed a tiny flag with “Cerca Trova”: essentially, seek and ye shall find. Was this Vasari’s signal that something was hidden underneath?

The technology of the 1970s did not provide much of an answer. In 2000 he returned to the hall with new technology.

The new analysis showed that the spot painted by Leonardo was right at the “Cerca Trova” clue. The even better news, obtained from radar scanning, was that Vasari had not plastered his work directly on top of Leonardo’s. He had erected new brick walls to hold his murals.

But how could anyone today know what lay behind the fresco and the bricks? Seracini was suggested to send beams of neutrons through the fresco.

One device can detect the neutrons that bounce back after colliding with hydrogen atoms, which abound in the organic materials (like linseed oil and resin) used by Leonardo. The other device can detect the gamma rays produced by collisions of neutrons with the atoms of different chemical elements. The goal is to locate the sulfur in Leonardo’s ground layer.

Developing this technology was difficult, but not as big a challenge as getting permission to use it. Once he gets permission, Seracini hopes to complete the analysis within a year. If he is right, then perhaps Vasari did Leonardo a favor by covering up the painting — and taking care to leave that cryptic little flag above the trove. NYT NEWS SERVICE

Friday, May 9, 2008

Once Lush Sahara Dried Up Over Millennia, Study Says

The grassy prehistoric Sahara turned into Earth's largest hot desert more slowly than previously thought, a new report says—and some say global warming may turn the desert green once again.

The new research is based on deposits from a unique desert lake in remote northern Chad.

Lake Yoa, sustained by prehistoric groundwater, has survived for millennia despite constant drought and searing heat.

The body of water contains an unbroken climate record going back at least 6,000 years, said study lead author Stefan Kröpelin of the Institute of Prehistoric Archaeology at the University of Cologne in Germany.

Ancient pollen, insects, algae, and other fossil clues preserved in the lake's sediments point to a gradual transformation to a desert environment.

Sahara Myth

The study contradicts past research that suggested the region dried up within a few hundred years. That research was based on windblown Saharan dust found in Atlantic Ocean sediments.

"This was a hypothesis used by most of the modelers and many of the scientific community who were not working themselves in the Sahara," Kröpelin said.

"To a large degree we can now show that such an abrupt drying out of the Sahara was a myth," he said.

The new study, which appears tomorrow in the journal Science, instead found evidence for a slow decline in tropical plants, followed by the gradual loss of savanna-type grasslands, and then the eventual spread of desert species.

Pollen samples revealed, for example, that the decrease in tropical trees accelerated after 4,800 years ago, while desert plants took root between 3,900 and 3,100 years ago.

Sand particles in the lake show that fierce desert winds didn't start picking up until about 3,700 years ago, the study found.

The only rapid change noted was in the lake itself, which switched from a freshwater to a salt lake between 4,200 and 3,900 years ago.

The transformation happened exactly in the time period when monsoon rains began moving away to the south, Kröpelin said.

This meant there was no longer surface water flowing in to counter salinity caused by evaporating water.

The study supports previous archaeological findings that human populations in the Sahara moved south over several millennia, following the monsoon rains, Kröpelin said.

First Reliable Record

About 20 feet (6 meters) of water evaporate from the lake every year, which is equivalent to the annual water consumption of about a million people, Kropelin noted.

"No team had ever succeeded in getting geological and paleoclimate information for the past 4,000 years since practically all the lakes had dried up, so there were no more geological archives available," he said.

The Lake Yoa data represent the first "reliable and high-resolution record" in the Sahara for verifying climate models, he added.

Such checks are important, he argues, "because if climate computer models don't work for the past, they probably won't work for the future."

Understanding climatic effects in the Sahara are especially important, since the region covers an area larger than the United States, Kröpelin said.

"Climate evolution in the Sahara reflects to a very large extent climate evolution on the African continent and beyond," he added.

Jonathan Holmes, of the Environmental Change Centre at University College London, was not involved in the study.

He wrote an accompanying commentary on Kröpelin's research in the same issue of Science.

The latest findings fill "an important gap in our understanding of the past 6,000 years of North African climate," he wrote in the article.

The study provides a more accurate picture of climate change in the region since the last ice age, because the "record comes from one of the few Saharan lakes in which sediments have accumulated without a break."

Similar lakes "probably do not exist," according to Holmes.

"However, improving existing geological records and using these to refine climate models would go a long way toward furthering our understanding," he wrote.

Modern Climate Change

Future research at Lake Yoa should provide clues to a potential regreening of the Sahara, triggered by the current trend of global warming, according to Kröpelin.

"I'm expecting reliable information on this possible trend," he said.

The last green phase, which started some 12,000 years ago, may be due to increased water evaporation from oceans. This led to monsoon rains that penetrated the interiors of tropical continents, he said.

"Now, today, man is probably causing the same thing," he said.

Kröpelin, who has studied the region for almost 30 years, said that since 1988 "there [has been] a strong indication [of] a return of increasing rains" in the eastern Sahara.

Already in some areas "you can see slight changes in the vegetation," he said.

Study confirms ancient Chile settlement is 14,000 years old

Scientists have confirmed that the famed Monte Verde archaeological site in southern Chile is about 14,000 years old, making it the earliest known human settlement in the Americas, the journal Science reported Thursday.

The age of Monte Verde has been the subject of controversy over the years, since estimates appeared to conflict with other archaeological evidence related to the settlement of North America.

The new findings support not only the age of the Monte Verde site, but also the coastal migration theory currently ascribed to by most scholars, which hypothesizes that people first entered the New World through the Bering land bridge more than 16,000 years ago.

The study, based on the first data compiled about the Monte Verde site in about a decade, identified nine species of seaweed and marine algae used as food by the settlement's inhabitants.

Carbon dating put the age of the seaweed samples at between 13,980 and 14,220 years old, confirming that the site was occupied some 1,000 years earlier than any other known human settlements in the Americas. The study appears in the May 9 issue of Science.

Discovered in 1976, Monte Verde is located in a peat bog about 500 miles (800 kilometers) south of Santiago, Chile.

Researchers say it could have supported between 20 to 30 people in a dozen huts along a small creek.

A wide variety of food has been found at the site, including extinct species of llama and an elephant-like animal called a gomphothere, shellfish, vegetables and nuts.

85,000-year-old finery recovered in Moroccan cave

Archaeologists have uncovered shells used for finery by prehistoric communities 85,000 years ago in a cave in eastern Morocco, the country's heritage institute said Tuesday.

A research team, led by archaeology and heritage institute (INSAP) member Abdel-Jalil Bouzouggar and Oxford University's Nick Barton, found the 20 perforated shells in a cave near Taforalt between March and April this year.

According to a statement from the Moroccan Ministry for Culture, the shells are the type prehistoric people would have worn. In 2007, Bouzouggar and Barton discovered 14 perforated shells in the same cave.

"This discovery shows that the making and use of objects of finery is very anchored in the traditions of Morocco's prehistoric people," said Bouzouggar, in whose opinion the country is the original center of artistic and symbolic creation.

Objects of finery discovered in Morocco are "now considered to be even more ancient than those discovered in Algeria, South Africa and in Palestine," said the Culture Ministry. Known as the "cave of pigeons," the 30-meter-deep, 10-meter high cave is situated 50 kilometers from Morocco's Mediterranean coast.