Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate Change Wiped Out Cave Bears 13 Millennia Earlier Than Thought

26.11.2008
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.

The new date coincides with a period of significant climate change, known as the Last Glacial Maximum, when a marked cooling in temperature resulted in the reduction or loss of vegetation forming the main component of the cave bears’ diet.

In a study published in Boreas, researchers suggest it was this deterioration in food supply that led to the extinction of the cave bear, one of a group of ‘megafauna’ – including woolly mammoth, woolly rhinoceros, giant deer and cave lion – to disappear during the last Ice Age.

They found no convincing evidence of human involvement in the disappearance of these bears. The team used both new data and existing records of radiocarbon dating on cave bear remains to construct their chronology for cave bear extinction.

“Our work shows that the cave bear, among the megafauna that became extinct during the Last Glacial period in Europe, was one of the earliest to disappear,” said Dr Martina Pacher of the Department of Palaeontology at the University of Vienna. “Other, later extinctions happened at different times within the last 15,000 years.”

Dr Pacher carried out the research alongside Professor Anthony J. Stuart of the Natural History Museum, London, and the University of Durham.

Many scientists previously claimed that cave bears survived until at least 15,000 years ago, but Dr Pacher and Professor Stuart claim that the methodology of these earlier studies included many errors in dating as well as confusion between cave bear and brown bear remains.

The pair also concluded, from evidence on skull anatomy, bone collagen and teeth, that these extinct mammals were predominantly vegetarian, eating a specialised diet of high-quality plants. Compared with other megafaunal species that would also become extinct, the cave bear had a relatively restricted geographical range, being confined to Europe, which may offer an explanation as to why it died out so much earlier than the rest.

“Its highly specialised mode of life, especially a diet of high-quality plants, and its restricted distribution left it vulnerable to extinction as the climate cooled and its food source diminished,” said Dr Pacher.

The brown bear, with which Ursus spelaeus shares a common ancestor, was spread throughout Europe and much of northern Asia and has survived to the present day.

“A fundamental question to be answered by future research is: why did the brown bear survive to the present day, while the cave bear did not?” said Professor Stuart. Answers to this question may involve different dietary preferences, hibernation strategies, geographical ranges, habitat preferences and perhaps predation by humans.

Cave bears were heavily built animals, with males growing up to around 1000kg. The maximum recorded weight of both Kodiak bears and polar bears – the largest bears living today – is 800kg, with averages of around 500kg.

Scientists have recovered a large quantity of cave bear remains from many cave sites, where they are believed to have died during winter hibernation. Caves provide an ideal environment for the preservation of these remains.

Despite over 200 years of scientific study – beginning in 1794 when a young anatomist, J. Rosenmüller, first described bones from the Zoolithenhöhle in Bavaria as belonging to a new extinct species, which he called cave bear – the timing and cause of its extinction remain controversial.

By far the best source of information on the appearance of cave bears in the flesh is to be found in red pigment cave paintings in the Grotte Chauvet in the Ardèche region of southern France. These are the only depictions in Palaeolithic art that can be attributed unambiguously to the cave bear.

Jennifer Beal | alfa
Further information:
http://www.boreas.dk
http://interscience.wiley.com

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Rutgers scientists discover 'Legos of life'

23.01.2018 | Life Sciences

Seabed mining could destroy ecosystems

23.01.2018 | Earth Sciences

Transportable laser

23.01.2018 | Physics and Astronomy

VideoLinks Science & Research
Overview of more VideoLinks >>>