NEWS&ANALYSIS
ANCIENT DNA
Farming’s Tangled European Roots
Europeans found clues linking modern Europeans to ancient farming cultures in the Near
East. But the genes of living people can’t capture the full story. And although more recent
ancient DNA studies had suggested a complex transition, those studies focused on local
areas (Science, 2 October 2009, p. 137).
Now, a team led by paleogeneticists
Guido Brandt of the Johannes Gutenberg University in Mainz, Germany, and
Wolfgang Haak of the University of Adelaide
in Australia present a pan-European view.
They built an ancient DNA data set 10 times
bigger than any previously studied. They
retrieved mitochondrial DNA (mtDNA) from
Lineages
100
Frequencies of genetic lineages
CREDITS (LEFT TO RIGHT): ADAPTED FROM G. BRANDT ET AL., SCIENCE 342, 6155 (11 OCTOBER 2013); STATE OFFICE FOR HERITAGE MANAGEMENT AND ARCHAEOLOGY SAXONY-ANHALT
Revolutions are rarely simple. Take the
spread of agriculture across Europe. About
8500 years ago, the story went, the world’s
first farmers swept into the continent from the
Near East via what is today Greece and Bulgaria. These pioneers of the so-called Neolithic Revolution then took over every corner
of Europe, displacing the hunter-gatherers
already living there and eventually reaching
the far corners of northwest Europe 2500
years later. In this scenario, living Europeans
trace much of their DNA back to that incoming tide of Near Eastern farmers.
Two papers in Science this week use
ancient DNA from prehistoric skeletons to
from the Near East about 7500 years ago. In
the second event, beginning about 6000 years
ago, central European farmers spread to
Scandinavia, where they mixed with huntergatherers to give rise to the Funnel Beaker
culture. These people were talented animal
herders, but also continued to hunt and fish.
And in a plot twist typical of the farming
story, farmers carrying this mixture of farmer
and hunter-gatherer genes then migrated
from Scandinavia back into central Europe
about a thousand years later, further complicating the genetic picture.
The third event, about 4800 years ago,
brought another wave of farmers from
the East into Central Europe. And in the
fourth, starting about 4500 years ago, metalwielding farmers of the Iberian Peninsula’s
Bell Beaker culture flowed into the heart of
Hunter-gatherer
Early/Middle Neolithic
Late Neolithic/Early Bronze Age
Other
80
60
40
20
0
6000 B.C.E.
5000 B.C.E.
4000 B.C.E.
Early Neolithic
3000 B.C.E.
Middle Neolithic
Late Neolithic
2000 B.C.E.
2000 C.E.
Early Bronze Age
Bumpy road to agriculture. The spread of farming across Europe was marked by changes in the frequencies
of genetic markers in ancient skeletons, such as this farmer from Germany (right).
decisively upend that simple scenario. One
paper, on page 257 of this issue, shows that
farming penetrated Europe in a series of fits,
starts, and reinvasions, leaving few modern Europeans with the genetic signature of
the first farmers. The other paper, published
online (http://scim.ag/Bollongino), focuses
on a single cave that served as a kind of prehistoric catacomb, and suggests that farmers
and foragers lived side by side for centuries.
Both papers “contradict the superficial
model of European hunter-gatherers being
submerged by hordes of farmers” from the
Near East, and instead suggest a long and
messy transition, says geneticist Martin
Richards of the University of Huddersfield
in the United Kingdom. The complex pattern of dispersals demonstrates that “ancient
DNA is finally fulfilling all the promises we
were making for it more than 20 years ago,”
he adds. “It’s at last making a reality of prehistoric population genetics” on people no
longer around to provide cheek swabs.
Back in the 1970s, researchers seeking
genetic signatures of the first farmers in living
364 people from 25 sites in the MittelelbeSaale region of Germany, an ancient crossroads that was home to at least nine archaeological cultures between 7500 and 3500 years
ago. Based on links between bones and artifacts, the team tied specific genetic markers
to many of the cultures, mostly farmers and
some foragers.
They also added 198 ancient mtDNA samples taken from skeletons in Europe and Asia,
plus 68,000 mtDNA sequences from modern
Europeans and Asians. The data allowed the
group to track the distribution and frequency
of mtDNA genetic markers, called haplogroups, through time and space, and to tease
out four so-called population events—major
migrations that reshaped the genetic landscape of Europe. (Because mtDNA is inherited only from the mother, it reveals a history
of women.)
The oldest event was the farmers’ first
foray into Europe, when the people of the
Linear Pottery culture (LBK), who grew
cereals, raised cattle, and crafted distinctive
ceramics, surged rapidly into central Europe
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VOL 342
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the continent. These last events greatly influenced modern genetic diversity, the team concludes. Just 30% of modern Europeans carry
the genetic signature of the earliest farmers;
signatures from later population movements
now dominate (see graph).
Princeton University archaeologist Peter
Bogucki questions whether mtDNA can yield
such a clear picture of group movements,
however. He argues that people may not have
moved around in cohesive groups and that
small bands of wanderers may have had the
cumulative effect of “smearing” genetic signatures over large areas.
Either way, the Neolithic transition
appears to have been a prolonged, nonlinear
process. It “was accompanied by many trials and errors,” as farmers sometimes learned
from indigenous hunter-gatherers how to live
in the varying landscapes of the European
frontier, Haak says.
11 OCTOBER 2013
181
NEWS&ANALYSIS
Recent studies have suggested that
farmers and hunter-gatherers interacted
(Science, 30 August, p. 950). The second of
the new papers uses fresh data from a cave
near the city of Hagen in western Germany
to show that in some cases, the two groups
were long-term neighbors. Excavations at
the cave since 2006 have revealed hundreds
of human bones from two levels. The oldest, dated between 11,200 and 10,300 years
ago, harbored remains of hunter-gatherers
from the so-called Mesolithic period. A later
level, dated from 5900 to 4900 years old, long
after farming was established in the area, was
assumed to correspond to Neolithic farmers.
Paleogeneticist Ruth Bollongino of the
Johannes Gutenberg University and her colleagues partially or completely sequenced
mtDNA genomes from five Mesolithic skel-
etons and 20 Neolithic ones. As expected,
all the Mesolithic people belonged to an
mtDNA group called haplogroup U, typical
of European hunter-gatherers. Eight of the
Neolithic skeletons showed markers typical
of farmers—but 12 were also haplogroup U.
Just who were those “Neolithic” people
with apparent Mesolithic ancestry? To find
out, Bollongino and her colleagues analyzed
the nitrogen and carbon isotopic composition
of the skeletons to get an idea of what they had
eaten. They got another surprise: While the
Neolithic farmers had apparently munched
on herbivorous domesticated animals, those
with U haplogroups did not. Instead, they ate
great quantities of fish. Thus, the team concludes that they were hunter-gatherers, not
farmers. “It is very surprising that two culturally different groups used the same burial
site” for 800 years, Bollongino says. “It is difficult to imagine that the two groups did not
know of each other.”
Indeed, Bollongino points out, the fisherfolk held onto their distinct lifestyle for 2000
years after the LBK farmers first came to
the area. “This study provides the best direct
evidence yet for groups with not only different modes of subsistence but also different ancestry coexisting for long periods after
the introduction of agriculture,” says geneticist Pontus Skoglund of Uppsala University
in Sweden (Science, 27 April 2012, p. 400).
Researchers are now busy on the next
wave of studies: using ancient nuclear DNA
to get an even crisper picture of what both
men and women were doing during a revolution that apparently came in fits and starts.
–MICHAEL BALTER
J A PA N
Windfall for Tiny University With Outsized Ambitions
182
To chart a course for building a formidable institution from scratch, Omi assembled
a Nobel-studded team of advisers. They recommended that OIST enroll only graduate
students, recruit half its faculty from abroad,
and emphasize interdisciplinary research
and education. Government planners gave
OIST greater autonomy than other universities by placing it directly under the prime
minister’s office rather than the education
ministry. That privileged treatment riled
Dorfan, a physicist and former director of
what is now the SLAC National Accelerator
Laboratory in Menlo Park, California. One
element, he says, is top-flight faculty members like Keshav Dani, a 34-year-old physicist who studied at Caltech and the University of California, Berkeley. Dani accepted
a position at OIST over several tenure-track
offers from top U.S. and European universities. When he first visited the campus, he
says, “they laid out a fantastic vision and I
was blown away.” His startup
package included an expensive laser setup for femtosecond
spectroscopy.
OIST also has a mandate to
spur economic development
in Okinawa. Toward that end,
Dorfan says, the university
in April will establish its first
startup company, which will
commercialize a technique that
determines the molecular structure of proteins developed by
Powerful patron. A doubled budget will allow OIST OIST biologist Ulf Skoglund.
President Jonathan Dorfan, pictured with Prime Min- The technique is expected to be
used for drug discovery.
ister Shinzo Abe, to plan a major expansion.
Dorfan says he understands
some academics and politicians, who also why administrators at other universities
criticized the decision to put the institute in might envy OIST’s support. But by raising
Okinawa Prefecture, better known as a vaca- standards of research and setting a precetion destination than as a research hotbed.
dent for recruiting foreign talent, he argues,
OIST appears to have few detractors now. OIST is bound to benefit other schools in
“We’ve been able to establish the key ele- Japan as well.
ments [that] success can be built on,” says
–DENNIS NORMILE
11 OCTOBER 2013
VOL 342
SCIENCE
Published by AAAS
www.sciencemag.org
CREDITS: OIST (2)
TOKYO—Japan is doubling its bet on a
young graduate university, based on a
remote island, that has aspirations of becoming a research powerhouse. If approved by
the Diet, the annual budget of the Okinawa
Institute of Science and Technology (OIST)
will jump from $110 million this year to
$204 million in 2014. OIST’s governors
met last week with Japanese Prime Minister
Shinzo Abe to outline expansion plans. “We
said we admire and congratulate the government for being willing to try to
realize the vision for this university,” says neuroscientist Torsten
Wiesel, a 1981 Nobel laureate
who chairs OIST’s board.
OIST opened for research in
2005 and began taking students last year.
Now it intends to double its faculty roll to
100 within 7 years,
and ultimately up it to
300—roughly the size
of the California Institute of Technology
(Caltech). Enrollment
is slated to climb from
100 now to 1000. The unabashed hope is “to
make OIST the best research university in
the world,” says Koji Omi, a politician who
conceived the institute a decade ago. “We
have momentum now and we should capitalize on that by rapidly beginning to grow,”
says OIST President Jonathan Dorfan.