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The famous stone figures of Easter Island
BBC Two, Thursday 9 January 2003, 9pm
The Mystery of Easter Island
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The Mystery of Easter Island - questions and answers

What is known about who the first Easter Islanders were and when they arrived?

Scientists have debated these questions for years. Easter Island is the most remote inhabited island in the world, and yet somehow primitive stone age people found their way there. They could have come either from South America to the east - a theory championed by the great Norwegian explorer Thor Heyerdhal - or from the islands of Polynesia to the west. Gradually over the years scientific opinion gravitated towards a Polynesian origin, based on linguistic, cultural and biological evidence. But it wasn't until recently that genetics finally solved the mystery. By examining DNA from the bones of ancient Easter Islanders, and comparing it with DNA from Polynesians and South Americans, scientists have found that the Easter Islanders were of Polynesian origin.

There is however one last possibility for those who cling to the South American hypothesis - that the very first Easter Islanders were from South America, but they were wiped out by a later Polynesian "invasion". Few scientists find this idea credible.

As to when they arrived, again there is disagreement. Dating of charcoal associated with human settlements has suggested dates as early as AD400, but most scientists now seem to favour a slightly later date - around AD700-800.

How did the first Easter Islanders find the most remote island on Earth?

The Polynesians were fantastic navigators - perhaps the greatest sailors the world has ever seen. Over the course of a few thousand years they colonised every island between Hawaii, New Zealand and Easter Island - it was the last great wave of human colonisation of the planet. Their navigation was based on several techniques. First, they used the stars to set and keep a course. Then they made use of a number of signs that meant they knew where land was long before it actually came into sight. For example, they knew that birds such as the frigate bird and the tern roost ashore and then feed at sea. Dawn and dusk flight paths pointed the way to land. Similarly they knew that land often helps clouds to form, so the presence of clouds on the horizon might also signify land.

Using these and other ancient techniques scientists have now undertaken all the great Polynesian voyages - including the journey to Easter Island - using reconstructed Polynesian canoes. A voyage was made recently, by the members of the Polynesian Voyaging Society, from Mangareva to Easter Island - the trip took was remarkably quick - it took just 17 days.

Is there any consensus on how the famous stone figures were made, moved and erected?

Few topics on Easter Island have aroused so much passion as the question of how the statues were moved. Of the 887 statues that were carved, 540 were moved out of the quarry. It was a monumental achievement for a primitive people armed only with stone tools. Island legend says that the statues 'walked' from the quarry to their platforms around the island. Charlie Love and Sergio Rapu are among those who take this as a hint that the statues were moved upright. Charlie cites the dozens of statues that have been abandoned en route to their platforms, many of which are broken in pieces. This could only have happened if they fell from a vertical position. On the other hand Jo Anne Van Tilburg points out that moving the statues vertically was inherently unstable, and it would surely have made more sense to move them horizontally. Whether they were moved upright or lying down, it is generally agreed that large numbers of logs would have been necessary to use as rollers. Even here though there is a dissenting view: Sergio Rapu argues that rounded rocks could have been used as pivots under the base of the statues - and indeed some statues do have a base which appears grooved in a way that might support this idea. The truth is that no-one really knows how the statues were moved. This is one mystery that modern science has been unable to solve.

How much use is folklore and oral history in unlocking the mystery?

The problem with folklore and oral history is that so few people survived the depravations of 19th century slavers and western disease. Most scientists now regard these sources as unreliable, although they are still studied for any clues they might add to the science.

How does the size, style or location of statues vary over time?

Considering that they were made for almost one thousand years, the statues - or moai as they are also called - are remarkably uniform in their design. Jo Anne Van Tilburg believes that the design was handed down in something akin to a guild of statue carvers, ensuring continuity. However, there are some differences in the statues.

It seems that over time they got bigger (although this is complicated because it is impossible to date the statues themselves, and the dating of the context in which they occur is not always as reliable as scientists would like it to be). There are one or two odd statues - the famous kneeling statue in the quarry for example, which appears to be unique. Some statues are noticeably slim, others are fatter. And then there are the strange 'topknots' or pukao which appear balanced on the heads of some but not all of the statues. These are thought to be a later design embellishment.

What similarities are there between the idolatry on Easter Island and that of other cultures in the Pacific?

Polynesian culture was based on ancestor worship, but nowhere else in the Pacific did this lead to the carving of giant stone statues. The closest any other of the nearby islands got to this was on Pitcairn where images were set up on platforms (as a memorial to dead chiefs). These were on a much smaller scale than those of Easter Island.

Is there any indication that the explorers considered the ill effect they might have on the Islanders when they landed in 1722?

Early explorers were often surprisingly sensitive to their impact - certainly by the standards of their time. Although the Dutch sailors shot a dozen islanders dead within minutes of their arrival, the journals of the expedition leaders make it clear that this was due to panic on the part of one man, and it was an action they apparently regretted. The impact of disease was not fully understood at the time. Later visitors in the 19th century included slave traders who regarded the Polynesian islanders as little better than cattle.

Why couldn't agriculture feed the Islanders when bird stocks plummeted and fishing became impossible?

Agriculture on Easter Island is a marginal activity. The biggest problem is a shortage of water. Rainfall is sporadic in the summer growing season, and the islanders had to devise ingenious ways of conserving moisture to grow their basic foodstuffs. For example they covered their 'fields' with thousands of rocks, which acted as a kind of stone mulch, preventing the evaporation of moisture from the soil in the dry winds which blow across the island. Sweet potato and other plants were grown in gaps between the rocks.

Additionally, soil quality on the island is poor. So when the statue cult fell apart (and with it the complex social organisation which had supported statue building) food production was also affected. In the absence of any trees, soil was either washed away, or had its nutrients leached out of it.

Is there any evidence for similar ecological self-destruction elsewhere in Polynesia?

On some Polynesian islands strategies were found for coping with severe environmental problems. A common response was to send out people to search for new islands nearby. That option wasn't available on Easter Island because the trees had been cut down, and there were in any case no islands nearby to provide a new territory.

Weblinks and bibliography
kon-Tiki Museum
Thor Heyerdahl
Easter Island
Jo Anne Van Tilburg, British Museum Press, 1994
Easter Island, Earth Island
Paul Bahn, John Flenley, 1992
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