10 MARCH 2006 VOL 311 SCIENCE www.sciencemag.org 1360
CREDIT: TERRY HUNT
NEWS OF THE WEEK
When Dutch explorers landed on a remote
Pacif ic island a few days after Easter Day
1722, they found eerie carvings of huge stone
statues, a barren landscape, and natives with
dwindling supplies of food and wood. Ever
since, Easter Island, now known as Rapa Nui,
has been considered a textbook example of a
once-thriving culture that doomed itself by
destroying its own fragile habitat.
Now a paper appearing online in Science
this week (www.sciencemag.org/cgi/content/
abstract/1121879) revises that story, implying
that construction of the statues and degradation
of the environment both began almost
immediately after humans set foot on the
island. New radiocarbon dates and a reanalysis
of old ones put humans first on Rapa Nui
at about 1200 C.E., 400 to 800 years later
than previously estimated and just 100 years
before the palm trees begin to vanish. “You
don’t have this Garden of Eden period for 400 to
800 years,” says lead author Terry Hunt of the
University of Hawaii, Manoa. “Instead, they
have an immediate impact. The destructionof-
the-environment story is on steroids.”
Other researchers, such as archaeologist
Patrick Kirch of the University of California,
Berkeley, agree that the new dates raise serious
questions about whether the Easter
Island residents ever lived sustainably on the
island. But some question the team’s dismissal
of some older radiocarbon dates. “I’m
not convinced they made the case for a later
occupation,” says Kirch.
By the time the Dutch landed, the Easter
Islanders—and the Polynesian rats that had
stowed away in their canoes—had destroyed
most of the subtropical trees and giant palms
that provided wood for canoes and for transporting
statues, as well as fuel for f ire. The
settlers also had wiped out many species of
birds. But most researchers thought that there
was a period during which the islanders had
lived in harmony with the environment,
before they taxed their resources with a complex
culture and statue building. Earlier
radiocarbon dates seemed to support that
idea, suggesting colonization between
800 C.E. and 1200 C.E. and ecological collapse,
as indicated by the disappearance of
palm trees, starting at least 400 years later.
Hunt and co-author Carl Lipo of California
State University, Long Beach, took eight samples
of wood charcoal from the bottom of the
oldest known archaeological site on the island,
called Anakena. When they got radiocarbon
dates that clustered at about 1200 C.E., Hunt at
first assumed the dates were wrong and put
them aside. But later he and Lipo decided to
scrutinize all earlier dates from Anakena, to
make sure they did not contain carbon from
marine organisms or old wood, which can
skew dates too old. After discarding what they
considered unreliable dates, the pair found a
high probability (50%) for the first human settlement
starting just after 1200 C.E. The evidence
does not rule out an occupation at
1000 C.E., but the probability is very low, says
Hunt. The new dates are a “signif icant
improvement” over the old ones, says radiocarbon-
dating expert Tim Higham of Oxford
University, U.K.
Although several researchers welcome the
rigorous analysis of dates, not everyone
agrees with the criteria the team used. “Some
of his criteria are fair; others are not,” says
zoologist David Steadman of the Florida
Museum of Natural History in Gainesville,
whose 1000 C.E. dates for Anakena were left
in the pair’s analysis.
The new results are in keeping with a trend
in the past decade toward later dates for colonization
of some of the outermost Pacif ic
islands. “This is an important paper, because it
is part of a revision on the chronology of the
Pacific that shows there is a big gap between
settling west Polynesia [e.g., Samoa] and the
marginal areas of south and east Polynesia,”
such as New Zealand, says archaeologist
Atholl Anderson of the Australian National
University in Canberra.
The new dates won’t be the final word on
the f irst colonization of Easter Island,
researchers say. “The chances you’re going
to f ind the f irst campf ire are pretty slim,”
says Steadman. “It will enliven the debate
and force everybody to take a critical look at
their dates.”
–ANN GIBBONS
Dates Revise Easter Island History
ARCHAEOLOGY
Monumental price. The building
of immense statues helped deforest
Easter Island.
Fran Bagenal of the University of Colorado,
Boulder, added that restoring money to those
two areas would “justify a delay in flagships”
such as the Solar Dynamics Observatory, to be
launched in 2008 to examine solar variability.
Some flagship missions already have been
delayed or canceled. A 2010 launch for
NASA’s $850 million Global Precipitation
Measurement mission has been stretched to
2013, and NASA has twice canceled plans for
a major spacecraft to study Jupiter’s moon
Europa. “This marks the first time in 4 decades
when we have no solar system flagship at all,”
noted Wes Huntress, a geophysicist at the
Carnegie Institution of Washington and a former
NASA space science chief.
That somber situation might look good to
life and microgravity scientists, who would
be largely shut out over the next 4 years of
space station construction and perhaps
longer. Before the Columbia disaster, NASA
planned 28 shuttle flights, many carrying scientific
equipment to and from the facility.
Now the number stands at 16. “It is the same
space station,” Griff in said. “But we are
largely deferring utilization.”
In good news for the station’s partners,
NASA agreed to launch the European and
Japanese scientif ic modules earlier than
planned so that non-U.S.-based research could
begin in 2008. In exchange for not launching a
Russian power module, NASA also will funnel
power to the Russian portion of the station. A
portion of that power was once designated for
experiments aboard the U.S. lab module.
–ANDREW LAWLER
Published by AAAS