Giant cave bears froze to death during the last Ice Age in Europe about 28,000 years ago, according to a study on Wednesday that cleared human hunters of driving them to extinction thousands of years later.
The largely vegetarian bears, weighing up to a ton and bigger than modern polar bears or Kodiak bears, apparently died off as a sharp cooling of the climate led to a freeze that killed off the fruits, nuts and plants they ate.
The bears vanished 27,800 years ago, or about 13,000 years earlier than previously believed, the scientists in Austria and Britain said in a study of bear remains using radiocarbon dating including at hibernation sites in the Alps.
"There is little convincing evidence so far of human involvement in extinction of the cave bear," they wrote in the journal Boreas. Some past reports have suggested that the cave bears' demise was linked to over-hunting.
Science & Technology
Mammoth bone with signs of a disease.
Mammoths were among the largest terrestrial mammals and roamed in Europe, Asia and North America in second half of Pleistocene. All mammoths died about 10 thousand years ago during last ice age. Many scientists tend to blame ancient hunters for extinction of mammoths. However, several researchers suggest another version of this "massacre". Researchers found mammoth bones, which carried traces of catastrophic changes - osteoporosis, osteomalacia (bone softening) and osteochondrosis nearly destroyed bones of giant vertebrates.
© The European Southern Observatory
Artist's impression of the planned European Extremely Large Telescope.
Artist's impression of the planned European Extremely Large Telescope.
The dream is to be able to see planets as small and as close to their host star as Earth is to the sun. That requires a telescope that can see objects nearly 3000 times smaller than those seen last month, and one that is not blinded by the host star's light - feats that are not possible with even the largest telescope today, the 10.4-metre Gran Telescopio Canarias in Spain's Canary Islands. But in less than a decade, a trio of gigantic telescopes will be able to carry off the task with ease.
© Ray Roberts/Rex Features
The gene might not play a role in our response to treatment for all conditions, and the experiment involved only a small number of people. Nonetheless, the discovery is a milestone in the quest to understand this phenomenon, which often blurs the results of clinical trials "To our knowledge, it's the first time anyone has linked a gene to the placebo effect," says Tomas Furmark of Uppsala University in Sweden.
He and his colleagues recruited 25 people with an exaggerated fear of public humiliation, otherwise known as social anxiety disorder. Participants had to give a speech at the start and end of an eight-week treatment - which unbeknownst to them and their doctors, was actually a placebo.
© CERN
In September this image was recorded when some of the first protons to be accelerated inside the Large Hadron Collider smashed into an absorbing device called a collimator at near light speed, producing a shower of particle debris. After a fault just nine days later, the accelerator faces a $29 million repair bill and will be working again in late summer 2009 at the earliest.
In September this image was recorded when some of the first protons to be accelerated inside the Large Hadron Collider smashed into an absorbing device called a collimator at near light speed, producing a shower of particle debris. After a fault just nine days later, the accelerator faces a $29 million repair bill and will be working again in late summer 2009 at the earliest.
The announcement comes in the same week an internal report revealed that the planned spring start-up won't now happen until late July 2009 at the earliest.
Repairs will cost 15 million Swiss francs, and spare parts another 10-20 million Swiss francs, says CERN spokesman James Gillies.
Buildings carved into the Pachallama peak mountainside in Peru by the Chachapoya
© Chris Peterson, Cloudbait Observatory
A composite, all-sky image of the 2008 Leonid outburst over Colorado.
A composite, all-sky image of the 2008 Leonid outburst over Colorado.
"On Nov. 17, 2009, we expect the Leonids to produce upwards of 500 meteors per hour," says Bill Cooke of the NASA Marshall Space Flight Center. "That's a very strong display."
Forecasters define a meteor storm as 1000 or more meteors per hour. That would make the 2009 Leonids "a half-storm," says Jeremie Vaubaillon of Caltech, who successfully predicted a related outburst just a few weeks ago.
It's not often that cultural and religious persecution makes countries more diverse, but the Spanish Inquisition might have done just that.
One in five Spaniards and Portuguese has a Jewish ancestor, while a tenth of Iberians boast North African ancestors, finds new research.
This melting pot probably occurred after centuries of coexistence and tolerance among Muslims, Jews and Christians ended in 1492, when Catholic monarchs converted or expelled the Islamic population, called Moriscos. Sephardic Jews, whose Iberian roots extend to the first century AD, received much the same treatment.
"They were given a choice: convert, go, or die," says Mark Jobling, a geneticist at the University of Leicester, UK. Some of those that became Christian would have ended up contributing genes to the Iberian pool.
One in five Spaniards and Portuguese has a Jewish ancestor, while a tenth of Iberians boast North African ancestors, finds new research.
This melting pot probably occurred after centuries of coexistence and tolerance among Muslims, Jews and Christians ended in 1492, when Catholic monarchs converted or expelled the Islamic population, called Moriscos. Sephardic Jews, whose Iberian roots extend to the first century AD, received much the same treatment.
"They were given a choice: convert, go, or die," says Mark Jobling, a geneticist at the University of Leicester, UK. Some of those that became Christian would have ended up contributing genes to the Iberian pool.
© NASA/JPL/U of Arizona
Step-like layers in a crater in the Arabia Terra region of Mars hint at past climate swings.
Step-like layers in a crater in the Arabia Terra region of Mars hint at past climate swings.
Discovered in four locations around a region just north of the equator called Arabia Terra, these sedimentary deposits have a regular, rhythmic pattern. Each step is a few metres tall, and the steps are bundled into groups of 10 .
Reading the pattern is only possible because of the stereo 3D view given by MRO's HiRISE camera, says lead author Kevin Lewis of Caltech.
A U.S.-led group, the Association of Space Explorers, says the international community must develop a coordinated response to the threat of asteroids.
Comment: But don't mention comets.