The emerging genetic picture of Europe:

-10 male lineages gave rise to the vast majority of Europeans
-Seven female lineages arose some 50,000 years ago
-80% of Europeans are descended from Paleolithic hunter-gatherers

Northern Europeans could be descended from as few as 50 individuals who survived the last ice age.

New DNA evidence suggests that a few hundred Stone Age hunter-gatherers were the ancestors of many modern day northern Europeans.

One theory is that the population expanded from a small enclave of foragers who retreated south to an area of the Balkans or Spain to escape the spread of the glaciers.

If true, northern Europeans share essentially the same genetic makeup as their bison-hunting forefathers.

According to Oxford University's Ryk Ward, the genetic data fits in surprisingly well with archaeological clues.

"Around 20,000 years ago, the population of Europe was forced to retreat into an area where there were no glaciers," says Professor Ward of the Institute of Biological Anthropology.

"From that population base, a very small number of individuals then became the ancestors of the current [northern] European population."


Out-of-Africa

He says it is impossible to specify exact numbers, but he believes that about 1,000 individuals gave rise to the modern northern European gene pool, and possibly as few as 50.

According to the joint US and UK team, northern Europeans diverged from their African roots as recently as 27,000 to 53,000 years ago.

"From a genetic standpoint, this is the first evidence that such a bottleneck occurred in Europeans," he told BBC News Online.

The evidence comes from a study of stretches of human DNA that contain individual variations of just a single letter in the genetic code.


Individual variation


Scientists are interested in studying these tiny molecular differences (single nucleotide polymorphisms or SNPs) because they could explain why some people are more susceptible to common diseases than others.

But they also provide a tool for studying our genetic history, by measuring the amount of shuffling of human DNA that has occurred over time.

Many scientists believe that humans arose in Africa, and then spread and conquered the rest of the world.

But during this long journey, the genetic history of the human race underwent a series of twists and turns.

Northern Europeans share SNPs with the Nigerian population, says Eric Lander of the MIT/Whitehead Center for Genomic Research in Cambridge, Massachusetts.

But he says the European samples show large clumps of unshuffled genetic material, suggesting a recent breeding bottleneck.

The study is reported in the 10 May issue of the journal Nature.

http://news.bbc.co.uk/1/hi/sci/tech/1334512.stm


Europe's 10 founding 'fathers'

More than 95% of European men alive today are descended from 10 ancient groups of forefathers, according to new genetic evidence.

Scientists believe that 80% of European men inherited their Y chromosomes from primitive hunter-gatherers who lived up to 40,000 years ago.

The other male ancestors are likely to have been migrants who arrived in Europe from the Near East about 10,000 years ago bringing with them farming technology.

The evidence comes from a new study of the male (Y) chromosome, which is passed only from father to son and can be used to trace paternal ancestry.


Genetic markers


An international research team studied genetic information from the Y chromosomes of more than 1,000 men from 25 communities across Europe and the Middle East.

Genetic tests revealed that 95% of the men could be grouped into 10 different categories, each representing a different paternal lineage.

Ornella Semino, a geneticist at the University of Pavia, Italy, and lead author of the Y chromosome research said the results showed "that about 80% of the European Y chromosomes trace back to Paleolithic ancestors and about 20% to the Neolithic farmers".

She said that most European men alive today would be able to trace their genetic roots by analysis of these Y chromosome markers.


Last glacial

The scientists, from eight European countries and the US, believe the male ancestors arrived in separate waves of migration.

The first two waves of migration into Europe happened during the Paleolithic period (25,000 to 40,000 years ago).

The other 20% of founding fathers probably arrived in one migration during the Neolithic period, about 10,000 years ago.

The settlers would have formed different clans, isolated by geographical features and glaciers.

But the advent of farming and the melting glaciers as the continent's climate warmed enabled the different groups to mingle.


Ancient settlers

The new data adds to previous evidence that modern European populations arose from the merging of local Paleolithic groups and Neolithic farmers arriving from the Near East after the invention of agriculture.

But scientists have debated whether it was local hunter-gatherers or newcomers bringing farming technology who passed on more of their genes.

The Y chromosome evidence suggests that the genetic template of modern European men was set by the hunter-gatherers as early as 40,000 years ago. Most modern European men still bear their genetic signature.

But the male gene pool was modified with the arrival of Neolithic farmers about 10,000 years ago.

Similar studies of mitochondrial DNA, a scrap of genetic material that is passed from mother to child, have traced the maternal ancestry of modern European women.

The Y chromosome data is "strikingly similar" to new findings on mitochondrial DNA said evolutionary geneticist Martin Richards of the University of Huddersfield, UK.

http://news.bbc.co.uk/1/hi/sci/tech/1015670.stm


Europe's seven female founders

Everyone in Europe is descended from just seven women.

Arriving at different times during the last 45,000 years, they survived wolves, bears and ice ages to form different clans that eventually became today's population.

These are the claims of Bryan Sykes, professor of human genetics at Oxford University.

Calling them "The Seven Daughters of Eve", Professor Sykes has individually named them Ursula, Xenia, Tara, Helena, Katrine, Valda and Jasmine. Professor Sykes arrived at his conclusion by studying mitochondrial DNA, which is passed down from mothers to children.

From 6000 random samples, and allowing for naturally occurring mutations, he established seven different clusters of DNA.


Ancestry traced

"It follows that the seven clusters must have sprung from one woman each," he told the BBC.

Professor Sykes says that the ancestry of 99% of Europeans can now be traced back to the seven women who founded the clans. He has also been quick to realise the commercial aspects of his project, founding a company, Oxford Ancestors, which offers to trace anyone's maternal ancestry for £120.

However, Professor Sykes went on to say that whilst his genetic work is rooted in fact, the names he has given to the women are hypothetical.

He says the names are an attempt to personalise DNA codes, which have traditionally been labelled alphabetically.

"For example, with the letter T, group T, I've just extended that to be the descendants of a woman called Tara," he said.


Ancient heritage

The study is being seen as further evidence of the way in which genetic research can shed light on human history.

His names for the women, which draw on Gaelic, Scandinavian and Persian heritage amongst others, reflect the huge geographic area from which modern Europeans descended.

His discovery also reinforces the theory that modern human beings have their origins in ancient Africa.

Professor Sykes found that the seven ancestral mothers have strong links to one of three clans that still exist in Africa today.

http://news.bbc.co.uk/1/hi/sci/tech/719376.stm