Lost landscape found off Scotland

14 July 2011 Last updated at 12:33 GMT By Martin Redfern BBC Science Explosions every 20 seconds sent sound waves to the oceanfloor revealing rolling valleys Geologists have discovered a vast new landscape that rose above the north Atlantic waves 56 million years ago.

It was caused by a sudden up-welling from the Earth's mantle and may explain rapid climate change that took place at about that time.

Discovered by UK researchers, the river-valley system is off the north west of Scotland, about 200km west of the Shetland Islands.

The results are published in the journal Nature Geoscience.

Over a six-month period the researchers reflected sound waves off the seabed to discover the new landscape.

They surveyed about 10,000 sq km of seabed; the sound waves reaching depths of up to several kilometres.

"It is supposed to be just boring layers of mud and sand down there," said Nicky White from the University of Cambridge, UK who was involved in the project.

"What we found was a big surprise: three-dimensional surfaces of hills and valleys," he told BBC News.

The lead author Ross Hartley, from the University of Cambridge, UK, plotted out the surfaces and discovered clear evidence of the drainage pattern of a river system, going down to what looked like a coastline.

It looked just like the surface of land, except that it was under a thousand metres of ocean, and a further 2000m of accumulated sediment.

Chipping away

The team managed to obtain drill samples; not complete cores that might contain macroscopic fossils, just chips from commercial drilling. But that was enough to prove that this had once been land.

In the sediments above and below there were the microscopic remains of plankton such as foraminifera. But at the suspected land surface they found pollen from terrestrial plants and lignite from rotted vegetation.

"This hidden landscape was above the waves between about 56 and 55 million years ago," said Dr White.

"It must have risen about a kilometre within 2 million years and then subsided just as quickly. That is extraordinary," he added.

Sudden pulse

In a second paper, Dr White proposes how that might have happened.

Sea level changes are not nearly enough to account for it, he thinks. It must be due to the slow but persistent upwards convection of mantle rock from great depths. It is what makes Iceland volcanic.

Fifty-six million years ago there must have been a sudden pulse in that plume. The material was not hot enough to result in partial melting and huge volcanic eruptions.

Instead, it spread out like ripples on a pond beneath the lithosphere, the 100km thick slab of hard rock that makes up the Earth's crust and the top of the mantle.

It may not have been an isolated event. There is evidence of other land surfaces higher up in the sediment column, though none seems quite as extensive as the landmass that rose from the Atlantic 56 million years ago.

That is so large that its edges disappear off the 10,000 square kilometre survey area.

Back then the climate was much warmer, and the boundary 55 million years ago between the Paleocene and the Eocene periods is marked by what is known as a thermal event - a very rapid rise in global temperatures accompanied by a rise in atmospheric carbon.

One explanation for the carbon is the sudden release of methane held as ice in gas hydrates on the ocean floor. The drop in pressure due to sudden uplift could explain its release.

The sudden rise of the range across the north Atlantic would also disrupt ocean circulation and currents, which transport heat around the planet, so that to would have had a significant effect on climate.

There is evidence on the sea floor of repeated pulses from the mantle plume so, say the researchers, it could happen again, but on timescales of millions of years.

They describe their results on the BBC's Material World on Radio 4 today. (14th July at 16:30 BST)

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'Giant wombat' found in Australia

6 July 2011 Last updated at 00:39 GMT By Phil Mercer BBC News, Sydney The Diprodoton optatum was an immense, hippo-sized beast Scientists in Australia have found the skeleton of a "giant wombat" which lived some two million years ago.

The plant-eating marsupial would have been the size of a four-wheel drive car and weighed three tonnes, experts say.

Its bones were found on a farm in north-eastern Australia's Queensland state.

The find is one of Australia's most significant pre-historic discoveries ever because the skeleton is complete, experts say.

It is the first time a complete skeleton of a Diprotodon optatum has been uncovered.

The animal was widespread across Australia about 50,000 years ago, when it is believed the first indigenous people lived.

'Wombat on steroids'

Prof Mike Archer, a professor of biological science at the University of New South Wales, described the discovery as extraordinary.

"We found the most gigantic marsupial ever known," he told the BBC.

"These were very huge animals but with pouches. If one tried to visualise what this thing looked like, you'd have to sort of think of a gigantic wombat on steroids."

The remains were unearthed at Floraville Station in northern Queensland - a region that has attracted scientists and fossil hunters for decades.

Researchers believe the area could contain a huge graveyard of mega-fauna that once roamed the Australian continent.

Every discovery offers more clues as to how and why they became extinct, possibly owing to hunting by humans or more likely because of a changing climate.

The specimen will be taken to the Riversleigh Fossil Centre, a World Heritage site in Queensland.

It is home to an array of prehistoric treasures, including the remains of a tree-dwelling crocodile, a carnivorous rat kangaroo and a marsupial lion.

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Remains found of early Europeans

20 June 2011 Last updated at 23:22 GMT By Jennifer Carpenter Science reporter, BBC News Teeth were among the ancient human remains found at the cave site Ancient remains uncovered in Ukraine represent some of the oldest evidence of modern people in Europe, experts have claimed.

Archaeologists found human bones and teeth, tools, ivory ornaments and animal remains at the Buran-Kaya cave site.

The 32,000-year-old fossils bear cut marks suggesting they were defleshed as part of a post-mortem ritual.

Details have been published in the journal PLoS One.

Archaeologist Dr Alexander Yanevich from the National Ukrainian Academy of Science in Kiev discovered the four Buran-Kaya caves in the Crimean mountains in 1991.

Since then, roughly two hundred human bone fragments have been unearthed at the site.

Among the shards of human bones and teeth, archaeologists have found ornaments fashioned from ivory, along with the abundant remains of animals.

The artefacts made by humans at the site allowed archaeologists to tie the ancient people to a cultural tradition known as the Gravettian.

This culture came to span the entire European continent and is named after the site of La Gravette in France, where this stone age culture was first studied.

Researchers were able to directly date the human fossils using radiocarbon techniques. The shape and form of the remains told the scientists they were dealing with modern humans (Homo sapiens sapiens).

Eastern promise

One thing that intrigued researchers was the scarcity of human long bones (bones from the limbs) in the caves.

The site yielded countless limb bones from antelope, foxes and hares.

Remains at the site bear cut marks where stone tools were used to remove flesh

But the human remains consisted of vertebrae, teeth and skull bones no larger than 12cm.

What is more, the positions of cut marks found on the human fragments were distinct from those found on the animal bones.

And while the bone marrow had been removed from butchered animals, it had been left alone in the case of the human remains at the site, explained co-author Sandrine Prat from the French National Centre for Scientific Research (CNRS) in Paris.

She suspects this demonstrates that human bones were processed differently from those of animals. Human flesh was removed as part of ritual "cleaning", not to be eaten.

Defining culture Continue reading the main story

These people had knives, lightweight tools, open air camps, they used mammoth bones to make tents”

End Quote Professor Clive Finlayson Director, Gibraltar Museum The finds offer anthropologists a glimpse into a very early and important human culture, said Professor Clive Finlayson, an evolutionary ecologist and director of the Gibraltar Museum.

"Gravettian culture is the culture that defines modern humans.

"These people had knives, lightweight tools, open air camps, they used mammoth bones to make tents," he said, adding that this was the earliest example of the Gravettian cultural tradition.

Professor Finlayson said that uncovering evidence of this culture in Ukraine gave weight to the idea that early modern people spread into Europe from the Russian plains, not north through the Balkans from the Middle East.

"What has excited me is that we have found evidence of humans where I would expect them to be, exploiting foods that I would expect them to be exploiting," Professor Finlayson told BBC News.

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New strain of MRSA found in cows

2 June 2011 Last updated at 23:39 GMT By Pallab Ghosh Science correspondent, BBC News Dr Garcia-Alvarez said finding a new strain in both in humans and cows is 'very worrying' A new strain of the MRSA "superbug" has been found in British cows and is believed to be infecting humans.

Environmental campaigners say the new strain has emerged because of the over-use of antibiotics by dairy farmers.

Dr Mark Holmes of Cambridge University, who led the research, said this was a "credible hypothesis".

The researchers, writing in the Lancet Infectious Diseases Journal, say there is no additional health risk from eating milk and dairy products.

'Financial pressure'

MRSA, or methicillin-resistant Staphylococcus aureus, is a drug-resistant form of a usually harmless bacterium which can be deadly when it infects wounds.

The 35 or so strains of antibiotic-resistant superbugs are genetically fairly similar. However, this new variety is very different and it is thought that it might have first emerged from cows.

Its discoverers have dubbed it "New MRSA"

Antibiotics are widely used by dairy farmers to treat cows with mastitis. However over-use means some bacteria become resistant and difficult to treat if humans become infected.

Dr Holmes said the problem might be exacerbated by financial pressures on diary farmers.

"If you drive your cows harder to produce more milk you get more mastitis," he told reporters at a news conference.

The Soil Association has called for a complete ban on routine use of antibiotics in farming.

Soil Association director Helen Browning said: "Dairy systems are becoming ever more antibiotic-dependent. We need to get farmers off this treadmill, even if that means that milk has to cost a few pennies more".

National Farmers' Union chief dairy adviser Rob Newberry said the health and welfare of cows were of "paramount importance" to British dairy farmers.

"In the interests of human and animal health, and animal welfare, it is important that veterinary medicines are administered as little as possible but as much as necessary," he said.

"Any antibiotic or veterinary medicine being administered to a food producing animal has strict conditions of use, including milk and meat withdrawal times, and in general, under European law, would only be available under prescription."

Dr Holmes and his colleague Dr Laura Garcia-Alvarez discovered the new strain while studying a bacterium known to cause mastitis in cows.

They found that, like other MRSA strains, it was resistant to the most commonly used antibiotics. However, the bug was found to be genetically very different.

Subsequent research showed that the strain was also present in humans.

Dr Garcia-Alvarez says that finding a new strain in both in humans and cows is "very worrying".

"Workers on dairy farms are at higher risk of carrying MRSA but we don't yet know if this translates to a higher risk [of them becoming ill]," she said.

'Very low risk'

Dr Holmes said very few people had been infected with the new strain, probably fewer than 100 a year in the UK. "But it does appear that the numbers are rising," he says.

The Health Protection Agency said the risk of becoming infected with the new strain was "very low".

Dr Holmes and Dr Garcia-Alvarez will now investigate the prevalence of the new strain and whether it is more or less harmful than current strains.

They also plan to conduct studies on farms to look for more MRSA strains of this type and explore any potential risks to farm workers.

MRSA is often found in hospitals and was linked to 1,593 deaths in 2007.

Since then the number of suspected fatal cases has fallen dramatically. There were 1,290 in 2008 and 781 in 2009.

A Department of Health spokesman said: "From the available evidence, we understand this new form of MRSA is rare in the UK and is not causing infections in humans.

"However, our expert committee, ARHAI, will be reviewing this issue at their next meeting and will consider potential medical, veterinary and food safety issues."

A Food Standards Agency spokesman said the study did not provide direct evidence that humans were being infected with MRSA from cattle.

"The risk of contracting this new strain of MRSA through drinking milk is extremely low because the vast majority of cows' milk is pasteurised and the pasteurisation process destroys all types of MRSA," he added.

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Deepest-living land animal found

2 June 2011 Last updated at 14:35 GMT By Jennifer Carpenter Science reporter, BBC News The worms survive in deep waters that are almost starved of oxygen Worms have been found living at depths in the Earth where it was previously thought animals could not survive.

Discovered in South African mines, the roundworms can survive in the stifling 48C (118F) water that seeps between cracks 1.3km beneath the Earth's crust.

The find has surprised scientists who, until now, believed only single-celled bacteria thrived at these depths.

Writing in the journal Nature, the team says this is the deepest-living "multi-cellular" organism known to science.

The researchers found two species of worm. One is a new species to science, which the scientists have named Halicephalobus mephisto after Faust's Lord of the Underworld.

The other is a previously known roundworm known as Plectus aquatilis.

Until now, only single-celled organisms, like bacteria and fungi, have been recovered from kilometres beneath the Earth's crust. The lack of oxygen is thought to stymie attempts by anything larger to make its home there.

But this has not stopped scientists looking.

Impossible depths

The Earth's subterranean world is only accessible to researchers in a handful of places worldwide where ore-mining requires drilling to reach depths of more than 3km.

Taking advantage of two such sites - the Beatrix and Driefontein gold mines in South Africa - the international team of researchers placed filters over the mines' bore-holes through which thousands of litres of groundwater pour.

From these samples they usually recover only bacteria; so the worms were a surprise.

"It scared the life out of me when I first saw them moving," said geo-microbiologist Dr Tullis Onstott of Princeton University in New Jersey, US. "They look like black little swirly things," he added.

These worms seem capable of surviving in very low levels of oxygen - at 1% of the levels found in most oceans, explained Dr Onstott.

But how did the worms get there?

The water in which the worms were found is between 3,000 and 10,000 years old, and so it is unlikely that the researchers brought the worms with them into the mines.

An ancient seep

The scientists, for now, believe that the animals originally came from the surface but got washed down into the cracks in the Earth's crust by ancient rainwater.

Dr Gaeten Borgonie, a member of research team, explained that he thinks the animals look very much like the tiny worms that live in rotting fruit and soil at the surface, and probably descended from them.

Worms at the surface experience great extremes of temperature and can survive being frozen and thawed, dehydrated and re-hydrated, he told BBC News.

Dr Borgonie believes that worms already have some of the "attributes necessary" to survive at these great depths. So it wasn't a surprise to him that the first multicellular organism to be found in the deep subsurface of the Earth was a worm.

The authors of the study expect to find other multicellular animals far beneath our planet's surface, and are preparing to descend again to search for others.

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Human brain's 'bat sight' found

26 May 2011 Last updated at 08:09 GMT Bats use sound to hunt The part of the brain used by people who can "see like a bat" has been identified by researchers in Canada.

Some blind people have learned to echolocate by making clicking noises and listening to the returning echoes.

A study of two such people, published in PLoS ONE, showed a part of the brain usually associated with sight was activated when listening to echoes.

Action for Blind People said further research could improve the way the technique is taught.

Bats and dolphins bounce sound waves off their surroundings and by listening to the echoes can "see" the world around them.

Continue reading the main story

[They] use echolocation in a way that seems uncannily similar to vision”

End Quote Dr Lore Thaler University of Western Ontario Some blind humans have also trained themselves to do this, allowing them to explore cities, cycle and play sports.

Brain scan

Researchers looked at two patients who use echolocation every day. EB, aged 43, was blinded at age 13 months. LB, 27, had been blind since age 14.

They were recorded echolocating, while microphones were attached to their ears.

The recordings were then played while their brain activity was being recorded in an fMRI machine.

Increased activity in the calcarine cortex was discovered.

Dr Lore Thaler, from University of Western Ontario, said: "This suggests that visual brain areas play an important role for echolocation in blind people."

The study looked at only two people so cannot say for certain what happens in the brains of all people who learn the technique, but the study concludes: "EB and LB use echolocation in a way that seems uncannily similar to vision."

Susie Roberts, rehabilitation officer at Action for Blind People, said: "This research into brain activity and echolocation is very interesting and improves our understanding of how some visually impaired people may be processing information to help them navigate safely.

"Further investigation may help to improve the way the technique is taught to people in the future, potentially improving their mobility and independence."

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