New DNA study in Science Traces the Genetic Roots of Modern
Photograph of "Neolithic burial HAL2"
from Halberstadt, Germany. This burial exemplifies the Linear Pottery
culture of the first Central European farmers, who lived about 7,500
years ago. The banded pottery and the flexed position of the legs
are hallmarks of this farming culture. The skeleton, excavated in
2000, was found in an excellent state of preservation and yielded
mitochondrial DNA type "N1a." The fact that 6 of the 24
skeletons are from this rare human lineage allowed the researchers
to investigate the mark the first European farmers left on the genetic
makeup of modern Europeans.
Image © Science
The farmers who brought agriculture to central Europe about 7,500 years
ago did not contribute heavily to the genetic makeup of modern Europeans,
according to the first detailed analysis of ancient DNA extracted from
skeletons of early European farmers.
The passionate debate over the origins of modern Europeans has a long
history. This work strengthens the argument that people of central European
ancestry are largely the descendants of "Old Stone Age," Paleolithic
hunter-gatherers who arrived in Europe around 40,000 years ago rather
than the first farmers who arrived tens of thousands of years later during
the Neolithic Age.
This paper appears in the 11 November 2005 issue of the journal Science
published by AAAS, the nonprofit science society.
The researchers from Germany, the United Kingdom and Estonia extracted
and analyzed DNA from the mitochondria of 24 skeletons of early farmers
from 16 locations in Germany, Austria and Hungary. Six of these 24 skeletons
contain genetic signatures that are extremely rare in modern European
Based on this discovery, the researchers conclude that early farmers did
not leave much of a genetic mark on modern European populations.
"This was a surprise. I expected the distribution of mitochondrial
DNA in these early farmers to be more similar to the distribution we have
today in Europe," said Science
author Joachim Burger from Johannes Gutenberg Universität Mainz in
"Our paper suggests that there is a good possibility that the contribution
of early farmers could be close to zero," said Science
author Peter Forster from the University of Cambridge in Cambridge, UK.
To get at questions surrounding the ancestry of modern Europeans, the
researchers studied mitochondrial DNA from early farmers in Central Europe.
Mothers pass mitochondrial DNA to their offspring primarily "as is,"
without mixing or recombination with mitochondrial DNA from fathers. Mitochondrial
DNA, therefore, provides a way for researchers to piece together how closely
members of a species are related, using maternal lineages as a guide,
In the new study, the researchers attempted to extract mitochondrial
DNA from the skeletons of 56 humans who lived in various parts of Central
Europe about 7500 years ago. These ancient humans all belonged to well
known cultures that can be identified by the decorations on their pottery
-- the Linearbandkeramik (LBK) and the Alföldi Vonaldiszes Kerámia
(AVK). The presence of these cultures in Central Europe marks the onset
of farming in the region. These farming practices originated in the "Fertile
Crescent" of the Near East about 12,000 years ago.
From bones and teeth of these 56 skeletons, the researchers extracted
mitochondrial DNA sufficient for analysis from 24 of the skeletons. Six
of the 24 early farmers belonged to the "N1a" human lineage,
according to genetic signatures or "haplotypes" in their mitochondrial
DNA that the researchers studied. These six skeletons are from archeological
sites all across central Europe. Few modern Europeans belong to this N1a
lineage, and those that do are spread across much of Europe.
The other 18 early farmers belonged to lineages not useful for investigating
the genetic origins of modern Europeans because their genetic signatures
from the scrutinized region of mitochondrial DNA are widespread in living
humans, according to the authors.
Geographic range of the first Central European farmers.
Image © Science
Using the tools of population genetics and a worldwide database of 35,000
modern DNA samples, the researchers investigated the genetic legacy of
early European farmers based on the fact that six of the 24 early European
farmers are from a lineage that is now extremely rare in Europe and around
the world. At least 8 percent of the early farmers belonged to the N1a
lineage, according to the researchers who estimate the range was between
8 and 42 percent.
Even this conservative estimate of 8 percent stands in stark contrast
to the current percentage of central Europeans who belong to the N1a lineage
— 0.2 percent. This discrepancy suggests that these early farmers
did not leave much of a genetic mark on modern Central Europeans, the
"It's interesting that a potentially minor migration of people into
Central Europe had such a huge cultural impact," said Forster.
Small pioneer groups may have carried farming into new areas of Europe,
the authors suggest. Once farming had taken hold, the surrounding hunter-gatherers
could have adapted the new culture and then outnumbered the original farmers,
diluting their N1a frequency to the low modern level. A range of archeological
research supports different aspects of this hypothesis, the authors say.
Alternatively, a different population may have replaced the early farmers
in Central Europe, eliminating most of the N1a types, but archaeological
evidence for this scenario is scant, according to the authors.
The authors: Wolfgang Haak, Barbara Bramanti, Guido Brandt, Marc Tänzer,
Kurt Werner Alt and Joachim Burger at Johannes Gutenberg Universität
Mainz in Mainz, Germany; Peter Forster, Shuichi Matsumura and Colin Renfrew
at University of Cambridge in Cambridge, UK; Richard Villems at Tartu
University in Tartu, Estonia; Detlef Gronenborn at Römisch-Germanisches
Zentralmuseum in Mainz, Germany. This study was supported by the Bundesministerium
für Bildung und Forschung (BMBF).
This press release is also available in German
and in French.
Daniel B. Kane
11 November 2005