http://news.nationalgeographic.com/news ... hgene.html
James Owen
for National Geographic News
July 19, 2005
Despite invasions by Saxons, Romans, Vikings, Normans, and others, the genetic makeup of today's white Britons is much the same as it was 12,000 ago, a new book claims.
In The Tribes of Britain, archaeologist David Miles says around 80 percent of the genetic characteristics of most white Britons have been passed down from a few thousand Ice Age hunters.
Miles, research fellow at the Institute of Archaeology in Oxford, England, says recent genetic and archaeological evidence puts a new perspective on the history of the British people.
"There's been a lot of arguing over the last ten years, but it's now more or less agreed that about 80 percent of Britons' genes come from hunter-gatherers who came in immediately after the Ice Age," Miles said.
These nomadic tribespeople followed herds of reindeer and wild horses northward to Britain as the climate warmed.
"Numbers were probably quite small—just a few thousand people," Miles added.
These earliest settlers were later cut off as rising sea levels isolated Britain from mainland Europe.
New evidence for the genetic ancestry of modern Britons comes from analysis of blood groups, oxygen traces in teeth, and DNA samples taken from skeletal remains.
Ice Age hunter-gathers also colonized the rest of northwest Europe, spreading through what are now the Netherlands, Germany, and France. But Miles said differences between populations can be detected in random genetic mutations, which occurred over time.
The most visible British genetic marker is red hair, he added. The writer Tacitus noted the Romans' surprise at how common it was when they arrived 2,000 years ago.
"It's something that foreign observers have often commented on," Miles said. "Recent studies have shown that there is more red hair in Scotland and Wales than anywhere else in the world. It's a mutation that probably occurred between 8,000 and 10,000 years ago."
Stonehenge Manpower
Britain's population in the late Stone Age may have much been larger than historians once supposed. For instance, scientists have calculated that it would have taken around 30 million hours to create Stonehenge.
"By the time Stonehenge was built you'd had about a thousand years of farming," Miles said. "The population's expanding, and people are getting together to form big labor forces to put up these big public buildings."
Population estimates based on the size and density of settlements put Britain's population at about 3.5 million by the time Romans invaded in A.D. 43.
Many historians now believe subsequent invaders from mainland Europe had little genetic impact on the British.
The notion that large-scale migrations caused drastic change in early Britain has been widely discredited, according to Simon James, an archaeologist at Leicester University, England.
"The gene pool of the island has changed, but more slowly and far less completely than implied by the old invasion model," James writes in an article for the website BBC History.
For the English, their defining period was the arrival of Germanic tribes known collectively as the Anglo-Saxons. Some researchers suggest this invasion consisted of as few as 10,000 to 25,000 people—not enough to displace existing inhabitants.
Analysis of human remains unearthed at an ancient cemetery near Abingdon, England, indicates that Saxon immigrants and native Britons lived side by side.
"Probably what we're dealing with is a majority of British people who were dominated politically by a new elite," Miles said. "They were swamped culturally but not genetically."
Genetic Continuity
"It is actually quite common to observe important cultural change, including adoption of wholly new identities, with little or no biological change to a population," Simon James, the Leicester University archaeologist, writes.
One such change is the emergence of a Celtic identity in Britain. There are no historical references to Celts in ancient Britain.
Miles explained that "Celts" was a name applied to tribes in Gaul—modern-day France—though their language shared the same root as those spoken by British tribes.
"In the 18th and 19th centuries, as Ireland, Wales, and Scotland started to assert national identity, they began to talk about themselves as Celts," Miles added.
Miles acknowledged that the techniques used to explore genetic ancestry are still in their infancy and that many more samples are needed to fully understand the origins of the British people.
"By mapping the genetic variability of humans around the world, geneticists can begin to track their dispersal, migrations, and interrelationships," Miles writes