Category: News stories

Early human fossils unearthed in Ukraine

  • Venue: BBC

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.

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

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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Scientists to sequence thousands of insect genomes

  • Venue: BBC

Thousands of insects are being lined up to have their genomes sequenced.

The five-year project will help researchers pinpoint vulnerable regions of insects’ genomes, which could be targeted with pesticides.

The project’s leaders hope the initiative will make a dent in the $50bn spent globally each year to control diseases transmitted by insects.

The final list of six-legged critters has yet to be finalised.

The project, called the 5000 Insect and Other Arthropod Genome Initiative, comes at a time when the costs of genome sequencing have fallen substantially and it is feasible to cheaply sequence large numbers of animals and plants.

Handfuls of bugs

Among the list of agriculturally important insects and other arthropods – animals with exoskeletons – to be sequenced are handfuls of bugs that act as disease vectors.

By comparing the genomes of these insects with those of their close relatives that don’t carry pathogens, researchers hope to pinpoint the genes that make one insect a disease-vector and another not.

What’s more, knowing the genes involved will help researchers better predict how insect immune systems will evolve in response to biopesticide control measures, such as Beauveria bassiana, a fungus used to control mosquitoes in malaria-ridden countries in Africa.

It is also hoped that the project will aid the search for suitable compounds for use as pesticides; ones that kill a targeted pest but leave the beneficial pollinating insects that also visit the crop plants unharmed.

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Powerful cosmic blast as black hole shreds star

  • Venue: BBC

Astronomers have spied a star’s swan song as it is shredded by a black hole.

Researchers suspect that the star wandered too close to the black hole and got sucked in by the huge gravitational forces.

The star’s final moments sent a flash of radiation hurtling towards Earth.

The energy burst is still visible by telescope more than two-and-a-half months later, the researchers report in the journal Science.

The Swift spacecraft constantly scans the skies for bursts of radiation, notifying astronomers when it locates a potential flare.

These bursts usually indicate the implosion of an ageing star, which produces a single, quick blast of energy.

But this event, first spotted on 28 March 2011 and designated Sw 1644+57, does not have the marks of an imploding sun.

What intrigued the researchers about this gamma ray burst is that it flared up four times over a period of four hours.

Astrophysicist Dr Andrew Levan from the University of Warwick, and his colleagues suspected that they were looking at a very different sort of galactic event; one where a passing star got sucked into a black hole.

The energy bursts matched nicely with what you might expect when you “throw a star into a black hole”, Dr Levan told BBC News.

Gasless centres

Black holes are thought to reside at the centres of most major galaxies. Some black holes are surrounded by matter in the form of gas; light is emitted when the gas is dragged into the hole. However, the centres of most galaxies are devoid of gas and so are invisible from Earth.

These black holes only become visible when an object such as a star is pulled in. If this happens, the star becomes elongated, first spreading out to form a “banana shape” before its inner edge – orbiting faster than the outer edge – pulls the star into a disc-shape that wraps itself around the hole.

As material drops into the black hole it becomes compressed and releases radiation that is usually visible from Earth for a month or so.

Events like these, termed mini-quasars, are incredibly rare – researchers expect one every hundred million years in any one galaxy.

The researchers used some of most powerful ground-based and space-based observatories – the Hubble Space Telescope, the Chandra X-ray Observatory and the Gemini and Keck Telescopes.

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Images capture moment brain goes unconscious

  • Venue: BBC

For the first time researchers have monitored the brain as it slips into unconsciousness.

The new imaging method detects the waxing and waning of electrical activity in the brain moments after an anaesthetic injection is administered.

As the patient goes under, different parts of the brain seem to be “talking” to each other, a team told the European Anaesthesiology Congress in Amsterdam.

But they caution that more work is needed to understand what is going on.

The technique could ultimately help doctors pinpoint damage in the brains of people suffering from stroke and head injury.

“Our jaws just hit the ground,” said anaesthesiologist Professor Brian Pollard from Manchester Royal Infirmary on seeing the images for the first time.

“I can’t tell you the words we used as it wouldn’t be polite over the phone.”

Although regions of the brain seem to be communicating as “consciousness fades”, Professor Pollard cautions that it is early days and that he and his team from the University of Manchester still have many brain scans to analyse before they can say anything conclusive about what is happening.

The finding supports a theory that is championed by Professor Susan Greenfield, from the University of Oxford, that unconsciousness is a process by which different areas of the brain inhibit each other as the brain shuts down.

The new technique, called Functional Electrical Impedance Tomography by Evoke Response (fEITER), is more compact than other brain imaging techniques, such as functional magnetic resonance imaging (fMRI), and so is easily transported into the operating theatre.

It involves attaching tens of electrodes to the patient’s head, which send low electrical currents through the skull. The currents are interrupted by the brain’s tissues and electrical signals.

Professor Pollard explained that the brain’s structures should not change over a minute-long scan, and so any differences that he and his team see as the patient falls asleep must therefore be due to changes in their brain’s activity.

It is hoped that this technique could be used to learn about the nature of consciousness, but it is also likely to help doctors make headway in monitoring the health of a person’s grey matter after they have suffered a head injury or stroke.

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Deepest-living land animal found

  • Venue: BBC

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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Mars ‘remains in embryonic state’

  • Venue: BBC

Mars formed in record time, growing to its present size in a mere three million years, more quickly than scientists previously thought.

Its rapid formation could explain why the Red Planet is about one tenth the mass of Earth.

The study supports a 20-year-old theory that Mars remained small because it avoided collisions with planetary building material.

The new finding is published in the journal Nature.

In our early Solar System, well before planets had formed, a frisbee-shaped cloud of gas and dust encircled the Sun.

Scientists believe that the planets grew from material pulled together by electrostatic charges – the same force that’s behind the “dust bunnies” under your bed.

These proto-planetary dust balls grew and grew until they formed what scientists term “embryo” planets.

These rocky masses were large enough to exert a considerable gravitational force on surrounding material, including other nascent planets.

Nudging each other with their gravitational fields, the embryos were often thrown from their regular orbits, sometimes into the path of another large rocky mass.

If collisions occurred, these nascent planets were either expelled from the Solar System or shattered into pieces. These pieces were often combined to form a larger planet. In fact, the Earth’s Moon is thought to be the result of an embryo planet colliding with our own planet.

By modelling this process, astro-physicists can determine the size of planets they expect to form at a given distance from the Sun. Mars is an outlier; it should have grown to around the size of the Earth, but remains about one-tenth its size.

Because of Mars’ small size, many scientists have long suspected that the Red Planet avoided the collisions that allowed other neighbouring planets to increase their girth.

Red Runt

By studying the chemical composition of meteorites, geochemist Dr Nicholas Dauphas of the University of Chicago in Illinois and Dr Ali Pourmand of the University of Miami in Florida joined forces to try to confirm this.

By measuring the concentration of elements Thorium and Hafnium in 44 space-rocks Dr Pourmand and Dauphas have come up with the most precise estimate of the time it took Mars to form.

Between 2 and 3 million years they suspect; short compared to the Earth, which is thought to have taken tens of millions of years to grow to its current size.

“We were pleasantly surprised because now we have precise evidence in support of the idea… that Mars is a stranded planetary embryo”, Dr Pourmand told BBC News.

He thinks that Mars was around more or less in its current size when the Earth was beginning to form.

Given this, Mars could not have experienced the same type of growth as the Earth and Venus, says Dr Pourmand.

It’s likely that Mars remains small because it deftly avoided colliding with other planets.

“The fact that Mars appears to have been left unscathed could just be down to luck,” says astrophysicist Dr Duncan Forgan of the University of Edinburgh, UK.

He explains that while it is unlikely that a planet could escape collisions for such long periods, statistically one expects it to happen from time to time.

When modelling planetary dynamics, researchers find it easier to predict what happens in general, he says, but it is much more difficult to determine what happens in specific solar systems, or in specific cases like Mars.

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Superbug Gene Found

  • Venue: Science Magazine

superbuggene_lgA gene that causes bacteria to become resistant to antibiotics has been found in drinking water in New Delhi, India. NDM-1 is commonly found in Escherichia coli but can spread to other bacteria thanks to their ability to swap DNA. The gene confers resistance to antibiotics, including potent, last-resort drugs called carbapenems.

India’s warm temperatures, over-crowding, and poor sanitation are likely to blame for the gene’s spread into the main water system from bacteria in people’s guts, write Timothy Walsh of Cardiff University in the United Kingdom and colleagues in a paper published online last week in The Lancet Infectious Diseases. The team, who found the gene in two out of 50 tap water samples and 51 of 171 samples taken from puddles and streams in the capital, say the gene could spread farther afield when tourists drink local water supplies and then return home.

NDM-1 has already been found in U.K. hospitals in bacteria infecting people who had medical treatment in India and those admitted with “traveler’s tummy.” The new finding raises concerns that resistant genes, so far found mainly in gut flora, are becoming widespread in natural environments, where they are highly mobile.

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Safe Sex, Duck Style

  • Venue: Science Magazine

Male mallard ducks (Anas platyrhynchos) are famous for their long, spiraling genitalia. Now scientists have discovered that they have something else to crow about. Mixing duck ejaculate with a common bacteria, Escherichia coli, researchers have found that mallard duck semen kills bacteria. Semen from males with more colorful bills harbored the greatest antibacterial activity, killing up to three times more bacteria than those with duller bills, the team reports online today in Biology Letters. The finding suggests that female ducks may be drawn to brightly colored males not just because they’re more flashy, but because they spread fewer germs through sexual intercourse.

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Can States Sue on Greenhouse Gas as a ‘Nuisance’? High Court Asks

  • Venue: Science Magazine

As the U.S. Environmental Protection Agency (EPA) is busy girding itself for a fight over new greenhouse gas emissions rules, the U.S. Supreme Court heard arguments today in a case on whether lawsuits over climate ought to be permitted.

At stake is whether greenhouse gas pollution may be considered a “nuisance” under U.S. law. The case stems from two 2004 federal lawsuits brought by seven states and several land-trust groups alleging that emissions from five major power companies could cause harm by contributing to global warming. Rising sea levels, loss of water in the Great Lakes, and reduced hydropower were among the injuries alleged by the plaintiffs; the lawsuits have since been combined, and two states have dropped out since the original suit was filed. The district court subsequently said in its decision that the case brought up a “political” question that the other branches of government, not the judicial branch, should consider, but an appeals court reversed that ruling. When the power companies appealed, the Supreme Court took the case.

In other pollution cases, the Supreme Court has supported suits claiming that pollution caused harm as a “nuisance” under common law, most often interpreted to prohibit noise and light pollution. The 80 minutes of occasionally spirited argument at the high court this morning focused on the two main issues in the greenhouse gas litigation: For the case to go forward, the plaintiffs must prove that the case has legal standing (they must show that the court is the right venue for resolving this dispute), and that the common law definition of nuisance can support suits over greenhouse gases. On the issue of standing, the court could rule that Congress or EPA is a more appropriate body to deal with pollution control.

The Obama Administration opposed the suing states in this case largely on grounds that they lack standing, marking a rare instance in which the Administration finds itself at odds with environmentalists on a major legal issue. (Environmentalists urged the states to try this legal strategy.) U.S. attorney Neal Katyal told the justices that the complexity of the issue suggests that the executive branch, namely EPA, is a better venue for controlling such an expansive type of pollution rather than the courts. “In the 222 years that this court has been sitting, it has never heard a case with so many potential perpetrators and so many potential victims,” he said in his opening remarks. “There are billions of emitters of greenhouse gasses on the planet and billions of potential victims as well.”

The attorneys for the power companies and the Obama Administration argued that the greenhouse gases case is fundamentally different from previous nuisance cases in which pollutants have played a central role. A landmark ruling by the Supreme Court in 1907, for example, found that a judge could stop a Tennessee copper company from polluting the Georgia environment under the nuisance doctrine. Such cases, Katyal said, “are essentially: A pollutes a river or something and hurts B.” But in the case of global warming pollution, he said, “A here is the world and B is the world, and that is such a difference in scale and scope to pose enormously difficult questions” about whether such suits should go forward.

If this case is allowed to proceed, asked the justices, should subsequent cases be limited to big polluters like the five targeted in this suit? “Your briefs talk a lot about how these are the five largest [U.S.] emissions producers, but I saw nothing in your theory to limit it to those five,” Justice Elena Kagan asked New York state attorney Barbara Underwood, who spoke on behalf of the six states in the suit. “Is there something that you think limits it to large emissions producers rather than anybody in the world?”

The states have argued that the larger the greenhouse gas emitter the stronger the connection linking pollution and potential harm. “These defendants,” Underwood said, speaking of the five polluters, “produce 650 million tons a year or 10% of U.S. emissions, and individually they produce amounts ranging from 1 to 3.5% of U.S. emissions.”

Those who challenged the states also suggested that courts would be ill-equipped to make the complex judgments that big regulatory agencies staffed with scientists and other experts make on a routine basis. Judges lack “the resources, the expertise” to be a “kind of super-EPA,” said Justice Ruth Bader Ginsburg.

But Underwood said courts could make such judgments—which could include determining how “substantial” an emitter must be to be found culpable—by relying on standards set by the agencies. She pointed to a cutoff set by EPA that limits regulated greenhouse gas polluters to those that emit 100,000 tons or more per year. “According to EPA’s own technical data, there would be at most a few thousand potential defendants.”

Because Justice Sonia Sotomayor recused herself—she sat on the panel that reviewed the issue in the appeals court—only eight justices heard the arguments. A 4-4 tie would mean litigation against the polluters could go forward, because that would leave in effect the earlier decision by the appeals court. While the tone of the questioning was largely skeptical toward the idea that such suits ought to go forward, divining a final ruling from the rough-and-tumble of oral argument can be difficult, especially because justices often ask tough questions of those they’re inclined to agree with—just to test their counterarguments. Eyes were squarely focused today on Justice Anthony Kennedy, often the swing judge when decisions are split 5-4 in favor of conservative decisions. Kennedy raised a concern that federal law, and EPA’s efforts to use that law, would necessarily “preempt” the common law. The court’s three liberal members, Ginsburg, Stephen Breyer, and Kagan, seemed skeptical on this issue, too.

At least one knowledgeable observer said a 4-4 tie was unlikely. “In short, this particular lawsuit seemed doomed, with the court’s biggest task figuring out how to say so without shutting the courthouse door entirely to such claims,” said longtime Supreme Court reporter Lyle Denniston.

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