Science | News & Views

Elephants know when they need a helping trunk

Elephants can work cooperatively if that is the only way to reach food. This kind of coordinated behaviour was once thought to be unique to our nearest primate relatives.

Joshua Plotnik of Emory University in Atlanta, Georgia, and his colleagues have previously shown that elephants seem to recognise themselves in a mirror. To test the animals’ understanding of cooperation, Plotnik and his colleagues have developed an elephant version of an experiment originally run with chimps.

In this experiment, a pair of animals can bring a platform bearing food within their grasp if both simultaneously pull on the ends of a rope threaded through it. If only one pulls the rope, it unthreads from the platform, leaving the food out of reach.

The Thai elephants the researchers studied learned to tug in unison with their trunks. In experiments in which one animal was held back by up to 45 seconds, its partner would wait for it to turn up before starting to pull. Most strikingly, in trials in which one end of the rope was curled up and out of reach, both animals backed away from the apparatus, making no attempt to pull on the rope.

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Frogs re-evolved lost lower teeth

Taken from BBC Online

Tree-dwelling Gastrotheca guentheri are the only frogs with teeth on both their upper and lower jaw. The reappearance of these lower teeth after such a long time fuels debate about whether complex traits are lost in evolution or if they can resurface. Scientists suggest this new evidence identifies a “loophole” in previous theories.

The Gastrotheca genus of frogs carry eggs on their backs
Commonly known as “marsupial frogs”, the Gastrotheca genus carry their eggs in pouches. Unlike marsupial mammals such as kangaroos however, the frogs’ pouches are on their backs. The species Gastrotheca guentheri is even more unusual, being the only known frog to have teeth on its lower jaw.

Dr John Wiens led a team of scientists from Stony Brook University, New York to investigate this exceptional feature. Their findings are reported in the journal Evolution.

“I combined data from fossils and DNA sequences with new statistical methods and showed that frogs lost their teeth on the lower jaw more than 230 million years ago, but that they re-appeared in G. guentheri within the past 20 million years,” explains Dr Wiens.

In the past, scientists have argued that traits “lost” in evolution cannot return, an assertion known as Dollo’s law. The return of lower jaw (mandible) teeth in G. guentheri after more than 200 million years could make evolutionary biologists reconsider this law.

“The loss of mandibular teeth in the ancestor of modern frogs and their re-appearance in G. guentheri provides very strong evidence for the controversial idea that complex anatomical traits that are evolutionarily lost can re-evolve, even after being absent for hundreds of millions of years,” Dr Wiens says.

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Public belief in climate change weathers storm, poll shows

Taken from The Guardian

The public’s belief in global warming as a man-made danger has weathered the storm of climate controversies and cold weather intact, according to a Guardian/ICM opinion poll published today.

Asked if climate change was a current or imminent threat, 83% of Britons agreed, with just 14% saying global warming poses no threat. Compared with August 2009, when the same question was asked, opinion remained steady despite a series of events in the intervening 18 months that might have made people less certain about the perils of climate change. Emails between climate researchers that were released online in November 2009 had led to unfounded suggestions that the scientific basis for global warming was flawed. World leaders also failed to agree to a global deal to combat warming and a mistake over the melting of Himalayan glaciers was handled badly by the UN’s science panel.

Supporters of action on climate change, from government to business to campaigners, will be relieved that this series of negative news failed to increase scepticism significantly. Polling by other organisations in early 2010 suggested a rise in the proportion of those unconvinced of the danger of climate change. But over the 18-month period between the ICM polls, the proportion of people saying climate change is not a current threat rose by just 3% and was balanced by a 3% rise in those saying it is a threat, representing a small polarisation of the opposing viewpoints.

The UK also suffered two unusually cold winters in 2009 and 2010. But three times more people said the freezing weather had actually made them worry more about global warming than those who were less worried. The finding runs counter to the idea that people are influenced more by local conditions than by reports of globally rising temperatures. It may also indicate an understanding of how warming is projected to increase extreme weather events and that people distinguish between changes in short-term weather and long-term climate.

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Bees fare better in town than country

Researchers at the University of Worcester analysed the pollen collected by bees from 45 hives on National Trust property around the country.
They found that bees in towns and cities have a much more “varied diet”, taking pollen from different flowers.

For example at Kensington Palace in London, where the Duke of Gloucester is keeping bee hives, the samples contained large amounts of pollen from rockrose, eucalyptus and elderberry.
In contrast bees in the countryside tended to rely on fields of crops. At Nostell Priory in Yorkshire and Barrington Court in Somerset, the samples were heavily dominated by oilseed rape with little other pollen types detectable.

In the last 20 years there has been a dramatic 50 per cent decline in bee numbers in Britain. Climate change, pesticides and even a mystery disease known as ‘colony collapse disorder have been blamed’.

Experts also believe that intensive farming may have contributed to the decline of bees because it means there is less wild flowers in the countryside to provide the insects with a ’varied diet’. Matthew Oates, Nature Conservation Adviser at the National Trust, said there are “precious few” pollen sources for bees in the countryside because farmland is either taken over for “monoculture” like wheat or barley or grazed for livestock.

He urged farmers to allow more wild flowers on field margins and to plant seed mixes in unused areas. Mr Oates also said the study showed how important urban beekeepers are to boosting numbers and called on more people to install a bee hive in the town.

“These are interesting early findings, seemingly backing what we’ve suspected for a while – namely that bees today often fare better in urban environments than in contemporary farmland,” he said.

Already the middle class fad for keeping bees has seen a doubling in hives over the past two years, according to the British Beekeepers Association, with many new beekeepers coming from towns and cities.

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Sun’s ‘quiet period’ explained

Solar physicists may have discovered why the Sun recently experienced a prolonged period of weak activity.

The most recent so-called “solar minimum” occurred in December 2008.

Its drawn-out nature extended the total length of the last solar cycle – the repeating cycle of the Sun’s activity – to 12.6 years, making it the longest in almost 200 years.

During a solar minimum the Sun is less active, producing fewer sunspots and flares.

The new research suggests that the longer-than-expected period of weak activity may have been linked to changes in the way a hot soup of charged particles called plasma circulated in the Sun.

The study, conducted by Dr Mausumi Dikpati of the National Center for Atmospheric Research in Colorado and her US colleagues, is published in the journal Geophysical Research Letters.

The Sun’s activity strengthens and weakens on a cycle that typically lasts 10.7 years. Since accurate records began in 1755, there have been 24 such solar cycles.

The 23rd cycle, which ended in December 2008, was both longer than average and had the smallest number of sunspots for a century. Sunspots are areas of intense magnetic activity that are visible as dark spots on the star’s surface.

Currents of fire
The new research suggests that one reason for the prolonged period of weak activity could be changes in the Sun’s “conveyor belt”.

Similar to the Earth’s ocean currents, the Sun’s conveyor transports plasma across its surface to the pole. Here, the plasma sinks into the heart of the Sun before rising again at the equator.

During the 23rd cycle, these currents of fire extended all the way to the poles, while in earlier cycles they only extended about two thirds of the way.

Dr Roger Ulrich of the University of California, Los Angeles, a co-author of the study, said the findings highlighted the importance of our monitoring of the Sun.

The research team used sophisticated computer simulations to show how changes in the conveyor might have affected cycle duration. They found that the increased length of the conveyor and its slower rate of return flow explained the prolonged 23rd cycle.

However, Dr David Hathaway, a solar physicist from Nasa’s Marshall Space Flight Center in Alabama, who was not involved in the latest study, argued that it was the speed and not the extent of the conveyor that was of real importance.

The conveyor has been running at record high-speeds for over five years. Dr Hathaway said: “I believe this could explain the unusually deep solar minimum.”

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Woolly mammoth extinction ‘not linked to humans’

Woolly mammoths died out because of dwindling grasslands – rather than being hunted to extinction by humans, according to a Durham University study.

After the coldest phase of the last ice age 21,000 years ago, the research revealed, there was a dramatic decline in pasture on which the mammoths fed.

The woolly mammoth was once commonplace across many parts of Europe.

It retreated to northern Siberia about 14,000 years ago, where it finally died out approximately 4,000 years ago.

The reasons for its extinction are unclear and have been a matter of heated scientific debate.

Some scientists have argued that it was principally the result of climate change while others say that it was driven by pressures of a growing human population, or even a cataclysmic meteor strike.

Now, according to Professor Brian Huntley of Durham University, that debate has been settled.

“What our results have suggested is that the changing climate, through the effect it had on vegetation, was the key thing that caused the reduction in the population and ultimate extinction of mammoths and many other large herbivores,” he said.

Professor Huntley and his colleagues created a computer simulation of vegetation in Europe, Asia and North America over the last 42,000 years.

They did this by combining estimates of what the climate was like during this period with models of how various plants grow under different conditions.

They found that the cold and dry conditions during the ice age, with reduced concentrations of carbon dioxide, didn’t favour the growth of trees.

So instead of forests there were vast areas of pasture, which was ideal for large herbivores, such as woolly mammoths. But as a result of a warmer, wetter climate and rising concentrations of carbon dioxide at the end of the ice age, trees emerged at the expense of the grasslands.

“During the height of the ice age, mammoths and other large herbivores would have had more food to eat,” said Professor Huntley.

“But as we shifted into the post-glacial stage, trees gradually displaced those herbaceous ecosystems and that much reduced their grazing area.”

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Climate change link to lizard extinction

By Victoria Gill
Science reporter, BBC News

Climate change could wipe out 20% of the world’s lizard species by 2080, according to a global-scale study.

An international team of scientists also found that rising temperatures had already driven 12% of Mexico’s lizard populations to extinction.

Based on this discovery, the team was able to make global predictions using an “extinction model”.

They conclude, in an article in Science journal, that “lizards have already crossed a threshold for extinctions”.

Although the grim prediction for 2080 could change if humans are able to slow global climate warming, the scientists say that a sharp decline in their numbers had already begun and would continue for decades.

The large research team was led by Barry Sinervo from the Department of Ecology and Evolutionary Biology at the University of California in Santa Cruz, US.

He said: “We are actually seeing lowland species moving upward in elevation, slowly driving upland species extinct, and if the upland species can’t evolve fast enough then they’re going to continue to go extinct.”

Lizards, the researchers say, are far more susceptible to climate-warming extinction than previously thought. Many species live right at the edge of their “thermal limits”.

Rising temperatures, they explained, leave lizards unable to spend sufficient time foraging for food, as they have to rest and regulate their body temperature.

A group of biologists including Dr Raymond Huey from the University of Washington in Seattle wrote an accompanying article in Science explaining the significance of the research.

Dr Huey and his colleagues said the predictions were “disturbing”.

But they pointed out that follow-up surveys were needed to confirm the results.

“Lizard populations rise and fall over time and failure to detect individuals during short surveys may indicate transient rarity rather than extinction,” they wrote.

But their article went on to say that the research team had shown that “climate-forced extinctions were not only in the future” but were “happening now”.

>>> Please read the full article at the BBC website, here

Brazil fire destroys snake and spider collection

A leading collection of dead snakes, spiders and scorpions housed at a research centre in Sao Paulo, Brazil, has been destroyed by fire.

The curator of the Butantan Institute said the destruction of the entire collection was a “loss to humanity”.

The nearly 80,000 preserved snakes and the thousands of specimens of spiders and scorpions were used in research.

Live animals housed nearby that are used to produce serums and vaccines were not harmed, the institute said.

“The entire collection was lost, the biggest collection of snakes in the world,” curator Francisco Franco said. “It’s a loss to humanity.”

A firefighter said the flammable liquid used to preserve the specimens helped spread the fire.

The cause of the blaze is being investigated.
Some of the specimens in the 100-year-old collection were of rare or extinct species.

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Cameron promises greenest government ever

New UK prime minister David Cameron has promised that his government will be the greenest ever.  

During a visit to the Department for Energy and Climate Change (DECC), Cameron said that the low carbon economy will be at the heart of his agenda and pledged to make all ministerial departments cut their carbon emissions by ten per cent.

“We’ve got a big, big opportunity here, I want us to be the greenest government ever. It’s a very simple ambition and one I’m absolutely committed to achieving,” he added.

He also highlighted his intention to focus on the green economy, saying: “We’ve got a real opportunity to drive the green economy, green jobs, green growth and make sure we have our share of the industries of the future.”

Liberal Democrat MP Chris Huhne has been placed in charge of the DECC, replacing Labour MP Ed Miliband, and it certainly seems like he has his work cut out for him if the government is going to place so much focus on environmental issues.

Huhne told reporters that he would be doing his bit to help cut carbon emissions by cycling to work.  But does the Con-Dem government have the potential to be the greenest ever?

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Gulf oil spill: plugging the leak

Since the Deepwater Horizon explosion two weeks ago, it has been hard not to view as primitive the efforts to contain the oil and prevent more of it leaking.

Whether it is the containment booms drafted in to prevent the oil washing ashore or early efforts to set the oil on fire, or even the attempts to funnel the leaking oil via giant sunken towers, the somewhat low-tech containment efforts starkly contrast with the often hi-tech methods usually witnessed in deep-sea drilling.

The latest BP plan being weighed up is similarly low-tech. Engineers may try to plug the well by pumping debris into it at high pressure, a method known as a “junk shot”.

“They are actually going to take a bunch of debris – some shredded up tyres, golf balls and things like that – and under very high pressure shoot it into the preventer itself and see if they can clog it up to stop the leak,” the US Coast Board Admiral Thad Allen told CBS News yesterday.

Tyres, golf balls, and “things like that” do not immediately inspire confidence, However Dr Simon Boxall, oceanographer at the National Oceanography centre in Southampton, Hampshire, said the unique conditions of the Deepwater Horizon spill – there has never been an oil leak at this depth before – mean all traditional methods “go out of the window”.

There have been blow outs in shallow water, but with those you’re looking at 100-metre-deep tops, where you can get divers down and you can get equipment down,” he said.

“It’s nothing compared to doing it 1,500m [5,000ft] down – this goes beyond all our technological knowhow and experience.”.

Boxall said a junk shot has been tried before, although he was only aware of one incident, which took place at a much shallower depth.

“We’re working in completely new territory, but the idea is not quite as daft as it sounds,” he said.

“Bear in mind the pressures at these depths are phenomenal, so what seems like an odd thing to bung a hole with at the surface can actually work quite well. Golf balls seem really quite hard but actually they’re quite soft.

“Certainly if you add a tonne of pressure per square inch to a golf ball then it starts to give. So I guess what they’re looking to do is use these things that are slightly plastic in their feel to bung into a hole which will help bung it up.”

The main problem for engineers is how to get the debris into the well almost a mile beneath the surface. The plan is to block the well beneath the semi-operational cut-off valves – at the moment, the well is partly shut off, restricting the oil flow – without making the spill worse.

“They’re planning to sort of try and insert them somehow magically before the cut off valve, but that doesn’t quite make sense,” Boxall said.

“All these things you can imagine are perfectly feasible on land if you had whatever technology was available to bung them in the hole.

“But when you’re looking at some mechanism to fire them into a hole when you’re a mile down in seawater, I can’t imagine what they would use, unless they’re using compressed air – but that is difficult at those depths anyway because the pressures are so great.”

He added: “There are one or two engineers out there who seem to be thinking: ‘This is ok as long as we don’t cause more damage than we solve.’”

BP’s ultimate solution to the leak is to drill a relief well, but that could take up to three months before that is completed. In the meantime, they will continue to try and position a cofferdam over one of the leaks today.

>>> Please read the full article at the guardian website, here