Bear market: Cave sheds light on ursine evolution

The ancestor of two main species of bear lived around 1.6 million years ago, according to analysis of bones found in the Chauvet Cave in southern France, better known for its dazzling examples of Stone Age artwork.

Well-preserved bear bones found in the cave were carbon-dated to 32,000 years before the present day, French researchers said in a study published on Monday.

Cave bears (Ursus spelaeus) lived in Europe and the Middle East from around 300,000 years ago to around 15,000 years ago, when they became extinct, they said.

The scientists also teased out pieces of so-called mitochondrial DNA -- material passed down on the maternal side -- from the bones and reassembled the sequence.

They then used this sample to calculate the species' history, using a method called the molecular clock, based on a regular rhythm of genetic change.

The cave bear was a sister to the brown bear and polar bear, and all descended from a common ancestor that lived around 1.6 million years ago, the investigators found.

The paper, by a team from the Institute of Biology and Technologies at France's Atomic Energy Commission (CEA), appears in the US journal Proceedings of the National Academy of Sciences (PNAS).

It is the first time that mitochondrial DNA has been recovered from subterranean remains of prehistoric animals.

The trick has been carried out on woolly mammoths and mastodons, whose remains were found in Siberian permafrost, and on the flightless New Zealand bird, the moa, which was wiped out several hundred years ago.

Caves, while less favourable than deep cold as a form of preservation, ensure stable temperatures, of 12-15 degrees Celsius (53.6-59 degrees Fahrenheit) and are sheltered from ultraviolet light.

"Our study ... demonstrates the feasibility of retrieving complete mitochondrial genomes from the subterranean milieu, an environment that contains remains for a variety of extinct species," the study says.

The Chauvet Cave, located in the Ardeche region of southern France, has the oldest-known cave paintings, with handprints and depictions of horses and other animals dated to around 30,000-32,000 years ago.

© 2008 AFP

Related stories:

Climate change wiped out cave bears 13 millennia earlier than thought
(PhysOrg.com) -- Enormous cave bears, Ursus spelaeus, that once inhabited a large swathe of Europe, from Spain to the Urals, died out 27,800 years ago, around 13 millennia earlier than was previously believed, scientists have reported.
Exploding asteroid theory strengthened by new evidence located in Ohio, Indiana
Geological evidence found in Ohio and Indiana in recent weeks is strengthening the case to attribute what happened 12,900 years ago in North America -- when the end of the last Ice Age unexpectedly turned into a phase of extinction for animals and humans -- to a cataclysmic comet or asteroid explosion over top of Canada.
Tuatara, the fastest evolving animal
In a study of New Zealand’s “living dinosaur” the tuatara, evolutionary biologist, and ancient DNA expert, Professor David Lambert and his team from the Allan Wilson Centre for Molecular Ecology and Evolution recovered DNA sequences from the bones of ancient tuatara, which are up to 8000 years old.
Tuatara evolving faster than any other species
New DNA research has questioned previous notions about the evolution of the tuatara.
Cave bears from the Carpathians as omnivorous as modern bears
Rather than being gentle giants, new research reveals that Pleistocene cave bears, a species which became extinct 20,000 years ago, ate both plants and animals and competed for food with the other contemporary large carnivores of the time such as hyaenas, lions, wolves, and our own human ancestors. The research is published this week in the Proceedings of the National Academy of Sciences (PNAS).
Anthropologists discover remains of earliest giant panda
Although it may sound like an oxymoron, a University of Iowa anthropologist and his colleagues report the first discovery of a skull from a "pygmy-sized" giant panda -- the earliest-known ancestor of the giant panda -- that lived in south China some two million years ago.
DNA analysis reveals rapid population shift among Pleistocene cave bears
Studying DNA obtained from teeth of ancient cave bears, researchers have been able to identify a shift in a particular population of the bears inhabiting a European valley in the late Pleistocene era. The findings illustrate the ability of DNA sequence analysis to reveal aspects of animal population dynamics in the distant past and potentially illuminate the influence of human migrations in animal population changes.
DNA of prehistoric cave bears sequenced
The genomic DNA sequencing of an extinct Pleistocene cave bear species – the kind of stuff once reserved for science fiction – has been logged into scientific literature thanks to investigators from the U.S. Department of Energy (DOE) Joint Genome Institute (JGI). The study, published in the June 2 online edition of the journal Science, has set the research community’s sights on traveling back in time through the vehicle of DNA sequencing to reveal the story of other extinct species – including our nearest relatives, the Neandertals.

News discussion:

General Science news