Bear DNA is clue to age of Chauvet cave art
19 April 2011 by _Michael Marshall_
(http://www.newscientist.com/search?rbauthors=Michael+Marshall)
EXPLORING a gorge in south-east France in 1994 for prehistoric artefacts,
Jean-Marie Chauvet hit the jackpot. After squeezing through a narrow
passage, he found himself in a _hidden cavern_
(http://www.newscientist.com/article/mg14519621.400-cave-art-work-of-great-talent.html)
, the walls of which
were _covered with paintings of animals_
(http://www.newscientist.com/article/mg14519621.400-cave-art-work-of-great-talent.html)
.
But dating the beautiful images - which featured in Werner Herzog's recent
documentary film _Cave of Forgotten Dreams_
(http://www.newscientist.com/blogs/culturelab/2011/03/ancient-paintings-unlocked-from-history.html)
- has
led to an _ugly spat_
(http://www.newscientist.com/article/dn3631-doubt-cast-on-age-of-oldest-human-art.html)
between archaeologists. Could the bones
of cave bears settle the debate?
_Within a year_
(http://www.newscientist.com/article/mg15020281.000-passions-run-high-over-french-cave-art.html)
of Chauvet's discovery, _radiocarbon
dating_
(http://www.newscientist.com/article/mg14619820.400-ancient-masters-put-painting-in-perspective.html)
suggested the images were between 30,000
and 32,000 years old, making them almost twice the age of the famous
_Lascaux cave art_ (http://www.lascaux.culture.fr/?lng=en#/en/00.xml) in
south-west France (see map). The result "polarised the archaeological world",
says
Andrew Lawson, a freelance archaeologist based in Salisbury, UK.
Lawson accepts the radiocarbon findings. "Nowhere else in western Europe
do we know of sophisticated art this early," he says. But _Paul Pettitt_
(http://www.sheffield.ac.uk/archaeology/staff/pettitt.html) of the University
of Sheffield, UK, is adamant that the paintings cannot be that old. The
dating study doesn't stand up, he claims, insisting that the paintings'
advanced style is enough to mark them as recent. To suggest otherwise, he
says,
would be like claiming to have found "a Renaissance painting in a Roman
villa".
Despite a comprehensive radiocarbon study published in 2001 that seemed to
confirm that the paintings were indeed 30,000 years old (Nature, _DOI:
10.1038/35097160_ (http://dx.doi.org/10.1038/35097160) ), Pettitt and his
colleagues were unconvinced. Two years later they argued that the cave walls
were still chemically active, so the radiocarbon dating could have been thrown
out by changes over the millennia to the pigments used to create the
paintings (Antiquity, vol 77, p 134).
To try to settle the controversy, Jean-Marc Elalouf of the Institute of
Biology and Technology in Saclay, France, and his team have turned to the
remains of cave bears. Along with mammoths and other huge mammals, cave bears
(Ursus spelaeus) dominated the European landscape until the end of the last
ice age.
The Chauvet cave contains several depictions of cave bears, and Elalouf
argues that these must have been painted while the bears still thrived in the
area. To pin down when the bears disappeared, his team collected 38
samples of cave bear remains in the Chauvet cave and
(http://www.newscientist.com/article/dn7462-dna-of-ancient-bears-successfully-sequenced.html)
.
They found that almost all the samples were genetically similar,
suggesting the cave bear population was small, isolated and therefore
vulnerable.
Radiocarbon dating showed the samples were all between 37,000 and 29,000
years old, hinting that by the end of that period they were extinct, at least
locally. Samples from a nearby cave, Deux-Ouvertures, gave similar results
(Journal of Archaeological Science, _DOI: 10.1016/j.jas.2011.03.033_
(http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WH8-52HS637-2&_user=88627
79&_coverDate=04/02/2011&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_so
rt=d&_docanchor=&view=c&_acct=C000000593&_version=1&_urlVersion=0&_userid=88
62779&md5=fb69e1ba22fe4c584a43fff8cc7404de&searchtype=a) ).
Given the age of the cave bear remains, "it is clear that the paintings
are very ancient", says Elalouf. _Michael Knapp_
(http://anatomy.otago.ac.nz/index.php?option=com_content&task=view&id=544&Itemid=46)
of the University
of Otago in Dunedin, New Zealand, who also studies cave bears, says he has
no doubts about the DNA analysis.
While we do not know exactly _when cave bears became extinct_
(http://dx.doi.org/10.1111/j.1502-3885.2008.00071.x) , all reliably dated
remains in
Europe are at least 24,000 years old, says _Martina Pacher_
(http://www.oeaw.ac.at/kfq/pacheren.html) of the Commission of Quaternary
Research in Vienna,
Austria. "So the results at Chauvet are not surprising, and I agree with
their conclusions," she says.
"We now have an independent line of evidence that the bears [in Chauvet]
date to before 29,000 years ago," Lawson says. "That bolsters the case for
an early date."
Pettitt remains unconvinced, calling the new research "sloppy". He says
that the team is trying to extrapolate the regional spread of the bears over
time by relying on evidence from just two caves.
Pettitt also questions whether the paintings show cave bears at all: brown
bears lived in the area long after the cave bears were gone. But Elalouf
says the two species can be distinguished by skull shape, and that the
paintings definitely show cave bears.
_http://www.newscientist.com/article/mg21028093.900-bear-dna-is-clue-to-age-
of-chauvet-cave-art.html_
(http://www.newscientist.com/article/mg21028093.900-bear-dna-is-clue-to-age-of-chauvet-cave-art.html)
