Ice Foiled Ancient Settlement of Britain Seven Times
Kate Ravilious in Edinburgh, Scotland
for National Geographic News
September 18, 2006
If at first you don't succeed, then try, try again.
This appears to have been the motto of ancient humans trying to inhabit the British Isles. These settlers were beaten back by ice sheets at least seven times before managing to permanently establish themselves, researchers say.
Scientists have managed to piece together much of the human history of the British Isles as part of the Ancient Human Occupation of Britain Project, a collaboration among archaeologists, paleontologists, and geologists that has been running for the past five years.
Those researchers have unearthed a wealth of new findings. Humans, it appears, came to the British Isles at least 700,000 years ago, 200,000 years earlier than previously thought, but began to establish permanent residence only around 12,000 years ago.
The director of the project, Chris Stringer of the Natural History Museum in London, England, outlined the project's key findings at the British Association Science Festival in early September.
"In human terms Britain was the edge of the universe," he told attendees.
Hot and Cold
There were eight waves of migration from continental Europe to the British Isles, the scientists say. Each migration attempt occurred when ice sheets retreated northward and the climate became warmer.
The ancient humans ventured to Britain during periods of low sea level (when much of the water was locked up in ice sheets), strolling across land bridges that now lie underneath the English Channel and parts of the North Sea.
But during harsh glacial periods, ice sheets traveled as far south as London, defeating the first seven invasions (map of the United Kingdom).
"Either [the ancient humans] went extinct, or they traveled south and hunkered down in warmer areas such as Spain," said Mark White of England's Durham University, one of the project archaeologists.
Crumbling Cliffs
Many of the archaeological finds have occurred along the east coast of England, where there has been dramatic coastal erosion in recent years.
The earliest evidence for human occupation in the British Isles has been discovered at Pakefield, a site dated to 700,000 years ago and located near Lowestoft on Britain's east coast.
No human remains were found, but more than 30 flint tools have been unearthed, providing sufficient proof of human occupation.
Animal and plant fossils from the same time period show that Pakefield was once very different.
"The climate was almost Mediterranean, and there were animals like hippopotamuses, hyenas, and lions roaming around," said Simon Parfitt, a mammal fossil specialist based at the Natural History Museum in London.
It's hard to say what the Pakefield people were like, Parfitt says. But the kind of tools they used and the animals they hunted indicate that the Pakefield settlers were more human than ape.
"Essentially they would have been very robust early humans, who walked about on two legs and subsisted from hunting and gathering," he said.
Further Invasions
The next wave of immigrants appears to have developed more sophisticated tools such as hand axes.
At Happisburgh, also on the east coast of England, the scientists discovered huge piles of butchered animal bones and hand axes at least 500,000 years old.
The majority of the finds have been in the south of the British Isles. "Ice sheets would have ground everything to pieces further north," Parfitt explained.
But that doesn't mean that early humans didn't go farther north. Some evidence of settlement has been found in Wales and in England's Midlands and north.
After several more unsuccessful incursions, the Neandertals (often spelled "Neanderthals") strode over to the British Isles around 60,000 years ago and survived by hunting big game, researchers say.
At a quarry near Norwich, in eastern England, Durham University's White and his colleagues have been examining a woolly mammoth butchery site.
The Neandertals appear to have been picking off the weakest of the beasts and herding them into a swampy area to kill them.
The findings are changing the way that scientists perceive the Neandertal people. "It seems they were a lot more savvy than people give them credit for," White said.
Nonetheless, the Neandertals couldn't withstand the extreme cold and were pushed out by the next ice age. (Related: "Neandertals' Last Stand Was in Gibraltar, Study Suggests" [September 18, 2006].)
Around 20,000 years ago the world experienced its most recent glacial period. The ice gradually retreated, and by around 12,000 years ago the modern British population began to arrive.
Climate Cycles
Most glacial cycles are believed to occur because of changes in planetary motions known as Milankovitch cycles. All across northern Europe, Russia, and China, ancient peoples were likely to have followed the advance and retreat of the ice sheets, scientists say.
However, humans didn't always take advantage of the warm periods in Britain.
"There were four warm periods where the ice retreated, but humans, as far as we know, didn't come," White said.
The sea level may have been too high for them to cross, or perhaps they were just content to stay in continental Europe, he says. Or evidence of their presence in Britain during these periods may just not have been found yet.
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