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?"