Trapping the Antimatter!

Creating matter’s strange cousin antimatter is tricky, but holding onto it is even trickier. Now scientists are working on a new device that may be able to trap antimatter long enough to study it.
Antimatter is like a mirror image of matter. For every matter particle (say an electron, for example), a matching antimatter particle is thought to exist (in this case, a positron) with the same mass, but an opposite charge.

The problem is that whenever antimatter comes into contact with regular matter, the two annihilate. So any container or bottle made of matter that attempts to capture antimatter inside would be instantly destroyed, along with the precious antimatter sample one tried to put inside the bottle.

Physicist Clifford Surko of the University of California, San Diegois hard at work to overcome that issue. He and his colleagues are building what they call the world’s largest trap for low-energy positrons – a device they say will be able to store more than a trillion antimatter particles at once.

The key is using magnetic and electric fields, instead of matter, to construct the walls of an antimatter “bottle.”

“We are now working to accumulate trillions of positrons or more in a novel ‘multicell’ trap– an array of magnetic bottles akin to a hotel with many rooms, with each room containing tens of billions of antiparticles.”

Surko presented his work today (Feb. 18) here at the annual meeting of the American Association for the Advancement of Science.

The researchers are also developing methods to cool antiparticles to super-cold temperatures so that the particles’ movements are slowedand they can be studied. The scientists also want to compress large clouds of antiparticles into high-density clumps that can be tailored for practical applications.

“One can then carefully push them out of the bottle in a thin stream, a beam, much like squeezing a tube of toothpaste. These beams provide new ways to study how antiparticles interact or react with ordinary matter. They are very useful, for example, in understanding the properties of material surfaces.”

Surko said another project is to create a portable antimatter bottle that could be taken out of the lab and into various industrial and medical situations.
“If you could have a portable trap it would greatly amplify the uses and applications of antimatter in our world.”

Antimatter may sound exotic, butit’s already used in everyday technology, such as medical PET (Positron Emission Tomography) scanners. During a PET scan, the patient is injected with radioactive tracer molecules that emit positrons when they decay. These positrons then come into contact with electrons in the body, and the two annihilate, releasing two gamma-ray photons. The gamma-ray photons are then detected by the scanner, giving a 3-D image of what’s going on inside the body.
[Via: LiveScience]

Mass Extinctions Linked to Loss in Biodiversity

Mass extinctions, that occured in Earth’s unrecorded history, are among a few questions yet to be answered. Two of the greatest mass extinctions in Earth’s history may have been caused by the loss of diversity in the oceans. New research shows that the die-off of species may have ultimately led to the collapse of marine ecosystems.The study could be an ominous warning for the future of life on Earth as modern ocean diversity begins to dwindle. Conservation biologists regularly note the precipitous decline of key species, such as cod, bluefin tuna, swordfish and sharks. Lose enough of these top-line predators (among other species), and the fear is that the oceanic web of life may collapse.

In a new paper in Geology, researchers at Brown University, Rhode Island, and the University of Washington used a group of marine creatures similar to today’s nautilus to examine the collapse of marine ecosystems that coincided with two of the greatest mass extinctions in the Earth’s history. They attribute the ecosystems’ collapse to a loss of enough species occupying the same space in the oceans, called ‘ecological redundancy.’ While the term is not new, the paper marks the first time that a loss of ecological redundancy is directly blamed for a marine ecosystem’s collapse in the fossil record. Just as ominously, the authors write that it took up to 10 million years after the mass extinctions for enough variety of species to repopulate the ocean – restoring ecological redundancy – for the ecosystem to stabilise.

It’s definitely a cautionary tale because we know it’s happened at least twice before. And you have long periods of time before you have reestablishment of ecological redundancy. If the theory is true, the implications could not be clearer today.
In effect, weare currently responsible for the sixth major extinction event in the history of the Earth, and the greatest since the dinosaurs’s disappeared, 65 million years ago,” the 2006 report states.

According to the United Nations-sponsored report Global Biodiversity Outlook 2, the population of nearly one-third of marine species that were tracked had declined over the three decades that ended in 2000.The numbers were the same for land-based species. Whiteside and co-author Peter Ward studied mass extinctions that ended the Permian period 250 million years ago and another that brought the Triassic to a close roughly 200 million years ago. Both periods are generally believed to have ended with global spasms of volcanic activity. The abrupt change in climate stemming from the volcanism, notably a spike in greenhouse in the atmosphere, decimated species on land and in the oceans, losing approximately 90% of existing marine species in the Permian-Triassic and 72% in the Triassic-Jurassic.

The widespread loss of marine life and the abrupt change in global climate caused the carbon cycle, a broad indicator of life and death and outside influences in the oceans, to fluctuate wildly. The authors noted these “chaotic carbon episodes” and their effects on biodiversity by studying carbon isotopes spanning these periods.

The researchers further documented species collapse in the oceans by compiling a 50-million-year fossil record of ammonoids, predatory squid-like creatures that lived inside coiled shells, found embedded in rocks throughout western Canada. The pair found that two general types of ammonoids, those that could swim around and pursue prey and those that simply floated throughout the ocean, suffered major losses. The fossil record after the end-Permian and end-Triassic mass extinctions shows a glaring absence of swimming ammonoids, which, because they compete with other active predators including fish, is interpreted as a loss of ecological redundancy.

It means that during these low-diversity times, there are onlyone or two [ammonoids] taxa that are performing. It’s a much more simplified food chain. Only when the swimming ammonoids reappear alongside its floating brethren does the carbon isotope record stabilise and the ocean ecosystem fully recover, the authors report. That’s when we say ecological redundancy is reestablished.

An alternate and more viable theory which was proposed by Victor Babbit is that unleashed sulpher dominated gases had caused the extinction of dinosaurs. Hover your eyes over this paper and analyze whether it is plausible. My answer is “Yes! Why not?”

[Source: CosmosMagazine]

New Propulsion System for Robotic LanderPrototype

NASA’s Robotic Lunar Lander Development Project at Marshall Space Flight Center has completed a series of hot fire tests and taken delivery of a new propulsion system for integration into a more sophisticated free-flying autonomous robotic lander prototype. The project is partnered with the Johns Hopkins University Applied Physics Laboratory to develop a new generation of small, smart, versatile robotic landers to achieve scientific and exploration goals on the surface of the moon and near-Earth asteroids.The new robotic lander prototype will continue to mature the development of a robotic lander capability by bringing online an autonomous flying test lander that will be capable of flying up to sixty seconds, testing the guidance, navigation and control system by demonstrating a controlled landing in a simulated low gravity environment.

By the spring of 2011, the new prototype lander will begin flight tests at the U.S. Army’s Redstone Arsenal Test Center. The prototype’s new propulsion system consists of 12 small attitude control thrusters, three primary descent thrusters to control the vehicle’s altitude, and one large “gravity-canceling” thruster which offsets a portion of the prototype’s weight to simulate a lower gravity environment, like that of the moon and asteroids. The prototype uses a green propellant, hydrogen peroxide, ina stronger concentration of a solution commonly used in homes as a disinfectant. The by-products after use are water and oxygen.

The propulsion hardware acceptance test consisted of a series of tests that verified the performance of each thruster in the propulsion system. The series culminated in a test that characterized the entire system by running a scripted set of thruster firings based on a flight scenario simulation.
The propulsion system is currently at Teledyne Brown’s manufacturing facility in Huntsville, for integration with the structure and avionics to complete the new robotic lander prototype. Dynetics Corp. developed the robotic lander prototype propulsion system under the management of the Von Braun Center for Science andInnovation both located in Huntsville,

This is the second phase of a robotic lander prototype development program. Our initial “cold gas” prototype was built, delivered and successfully flight tested at the Marshall Center in a record nine months, providing a physical and tangible demonstration of capabilities related to the critical terminal descent and landing phases for an airless body mission.

The first robotic lander prototype has a record flight time of ten seconds and descended from three meters altitude. This first robotic lander prototype began flight tests in September 2009 and has completed 142 flight tests, providing a platform to develop and test algorithms, sensors, avionics, ground and flight software and ground systems to support autonomous landings on airless bodies, whereaero-braking and parachutes are not option.

[Source: Nasa]

Apollo 8: Christmas at The Moon

Christmas Eve, 1968. As one of the most turbulent, tragic years in American history drew to a close, millions around the world were watching and listening as the Apollo 8 astronauts — Frank Borman, Jim Lovell and Bill Anders– became the first humans to orbit another world. As their command module floatedabove the lunar surface, the astronauts beamed back images of the moon and Earth and took turns reading from the book of Genesis, closing with a wish for everyone “on the good Earth.” Borman recalled during 40th anniversary celebrations in 2008.

We were told that on Christmas Eve we would have the largest audience that had ever listened to a human voice.
The first ten verses of Genesis is the foundation of many of the world’s religions, not just the Christian religion. There are more people in other religions than the Christian religion around the world, and so this would be appropriate to that and so that’s how it came to pass.

The mission was also famous for the iconic “Earthrise” image, snapped by Anders, which would give humankind a new perspective on their home planet. Anders has said that despite all the training and preparation for an exploration of the moon, the astronauts ended up discovering Earth. The Apollo 8 astronauts got where they were that Christmas Eve because of a bold, improvisational call by NASA. With the clock ticking on President Kennedy’s challenge to land on the moon by decade’s end, delays with the lunar module were threatening to slow the Apollo program. So NASA decided to change mission plans and send the Apollo 8 crew all the way to the moon without a lunar module on the first manned flight of the massive Saturn V rocket.

The crew rocketed into orbit on December 21, and after circling the moon 10 times on Christmas Eve, it was time to come home. On Christmas morning, mission control waited anxiously for word that Apollo 8’s engine burn to leave lunar orbit had worked. They soon got confirmation when Lovell radioed, “Roger, please be informed there is a Santa Claus.”

The crew splashed down in the Pacific on December 27. A lunar landing was still months away, but for the first time ever, men from Earth had visited the moon and returned home safely.

[Image Details: Thirty-five years ago this Christmas, a turbulent world looked to the heavens for a unique view of our home planet. This photo of “Earthrise” over the lunar horizon was taken by the Apollo 8 crew in December 1968, showing Earth for the firsttime as it appears from deep space.

Astronauts Frank Borman, Jim Lovell and William Anders had become the first humans to leave Earth orbit, entering lunar orbit on Christmas Eve. In a historic live broadcast that night, the crew took turns reading from the Book of Genesis, closing with a holiday wish from Commander Borman: “We close with good night, good luck, a Merry Christmas, and God bless all of you — all of you on the good Earth.”]
Wishing happy holiday to all WeirdSciences Readers.
[Source: Nasa]
[Editor’s Note: The interruption in continuation of publishing article may be continued till 10 January.]

Dinosaurs Were Taller than Thought!

Jurassic Park’s velociraptors were awe fascinating in intelligence( Remember the social behaviour of velociraptors was quite akin to primitive human civilization). I don’t know if some of them had survived the catastrophes and developed an advanced civilization that flourished during post cretaceous era(though it’s unlikely that they survived the catastrophe if we are going to consider the research by Victor Babbitt in which he proposed that SO2 unleashed after comet impact might have destroyed the eggs of Dinosaurs.).

New research showcases that Dinosaurs were taller than thought. Some dinosaurs may have been at least 10% taller than previously thought, U.S. palaeontologists said in a study that found the creatures had large amounts of cartilage.The dinosaurs had thick layers of cartilage in their joints that may have added more than 30 centimetres to their height, according to researchers at the University of Missouri (MU) and Ohio University, who said this may have changed their speed and posture.

Our study of the limbs of modern-day relatives of dinosaurs shows that dinosaurs were significantly taller than original estimates.

[Image Details: A three horned dinosaur estimated to have reached about 7.9 to 9.0m (26.0–29.5 ft) in length, 2.9 to 3.0 m (9.5–9.8 ft) in height, and 6.1–12.0 tonnes (13,000–26,000lbs) in weight. The most distinctive feature is their large skull, among the largest of all land animals. It could grow to be over 2 m (7 ft) in length, and could reach almost a third of the length of the entire animal.]
She explained that many dinosaurs’ long bones, such as the femur or tibia, lack major articulations and have rounded ends with rough surfaces. This indicated that very thick cartilages formed these structures, and therefore the joints themselves, and would have added significant height to certain dinosaurs. In contrast, mammal bones have small protrusions at their ends that help them connect with other bones at a joint. The bones are then linked with a very thin layer of cartilage.

Using cartilage to measure height

The study, which was published in PLoS-ONE, shed further light on how reptiles and mammals such as humans build their joints with different amounts of cartilage and bone.The researchers compared articulations of ostriches and alligators – the closest living relatives to dinosaurs – to fossilised limbs of dinosaurs like Tyrannosaurus rex and Triceratops.

They found that alligators’ and ostriches’ limbs included six to 10% cartilage. By applying a ‘cartilage correction factor,’ Holliday, a researcher, found that many theropod dinosaurs, such as Tyrannosaurus, were only modestly taller, while ornthischian and sauropod dinosaurs like Triceratops and Brachiosaurus, may have been 10% taller or more.

Brachiosaurus, which was previously thought to be 13 metres tall, may actually have been more than a foot taller with the additional joint cartilages, according to the researchers.

This study is significant because it shows that bones can’t always speak for themselves. To understand how dinosaurs moved, we need to analyse the bones as they were inside their bodies, including their cartilage. Dinosaurs bones mounted in museums in fact do not accurately reflect the creatures’ height when they were alive because the cartilage caps and other soft tissues were lost.

A simple conclusion can be withdrawn by now that dinosaurs were more furious that we could imagine.

[Source: CosmosMagazine]

GJ 1214b: Probing the Atmospheres of Super Earths

Meet GJ 1214b: one of the most Earth-like planet ever found outside oursolar system. It’s not exactly Earth’s twin: It’s about six times bigger, a whole lot hotter and made mostly of water. But compared to the giant gas balls that account for nearly every other extrasolar planet everfound, it’s pretty darn close. And through a fortunate happenstance of cosmic geometry, astronomers will be able to study GJ 1214b in great detail.
GJ 1214b, first discovered in December 2009, is 2.7 times the size of Earth and 6.5 times as massive. Previous observations ofthe planet’s size and mass demonstrated it has a low density for its size, leading astronomers to conclude the planet is some kind of solid body with an atmosphere. The planet orbits close to its dim star, at a distance of 0.014 astronomical units. An astronomical unit is the distance between Earth and the sun, approximately 93 million miles. Its host star lies about 40 light-years from Earth in the constellation of Ophiuchus (the Serpent Bearer). It is a faint star, but it is also small, which means that the size of the planet is large compared to the stellar disc, making it relatively easy to study. The planet travels across the disc of its parent star once every 38 hours as it orbits at a distance of only two million kilometres: about seventy times closer than the Earth orbits the sun. GJ 1214b circles too close to its star to be habitable by any ‘Earthly’ life forms.

[Image Details: Using a ground-based telescope, astronomers, including two NASASagan Fellows, made the first characterizations of a super-Earth’s atmosphere. A super-Earth is a planet up to three timesthe size of Earth and up to 10 times the weight.]

The atmosphere around a super-Earth exoplanet has been analysed for the first time by an international team of astronomers using ESO’s Very Large Telescope. The planet, which is known as GJ 1214b, was studied as it passed in front of its parent star and some of the starlight passed through the planet’s atmosphere. We now know that the atmosphere is either mostly water in the form of steam or is dominated by thick clouds or hazes. The findings, reported are a significant milestone toward eventually being able to probe the atmospheres of Earth-like planets for signs of life.

To study the atmosphere, the team observed the light coming from the star as the planet passed in front of it. During these transits, some of the starlight passes through the planet’s atmosphere and, depending on the chemical composition and weather on the planet, specific wavelengths of light are absorbed. The team then compared these precise new measurements with what they would expect to see for several possible atmospheric compositions. This same type of technique has been used to study the atmospheres of distant “hot Jupiters,” or Jupiter-like planets orbiting close to their stars, and found gases like hydrogen, methane and sodium vapor.

In the case of the super-Earth, no chemical fingerprints were detected; however, this doesn’t mean there are no chemicals present. Instead, this information ruled out some possibilities for GJ 1214b’s atmosphere, and narrowed the scope to either an atmosphere of water steam or high clouds. Astronomers believe it’s more likely the atmosphere is too thin around the planet to let enough light filter through and reveal chemical fingerprints.

The team determined the planet, GJ 1214b, is either blanketed with a thin layer of water steam or surrounded by a thick layer of high clouds. If the former, the planet itself would have an icy composition. If the latter, the planet would be rocky or similar to the composition of Neptune, though much smaller.

This is the first super-Earth known to have an atmosphere. But even with these new measurements, we can’t say yet what that atmosphere is made of. This world is being very shy and veiling its true nature from us. A steamy atmosphere would have to be very dense – about one-fifth water vapor by volume — compared to our Earth, with an atmosphere that’s four-fifths nitrogen and one-fifth oxygen with only a touch of water vapor. During the next year, we should have some solid answers about what this planet is truly like.

That list of ingredients raises at least the possibility of life. With an estimated temperature of 370 degrees Fahrenheit, GJ 1214b is an unlikely incubator (Earth’s toughest extremophile, a microbe that lives in deep-sea volcanic vents, maxes out at 284 degrees) but it’s not impossible.

[Source: NASA/ESO]

Why the Universe is Made of Matter: CERN Exploring to Answer?

Scientists at CERN said they’ve trapped dozens of anti-hydrogen atoms, a technical breakthrough that will allow them to explore why the universe is made of matter. Under a theory expounded in 1931 by the eccentric British physicist Paul Dirac, when energy transforms into matter, it produces a particle and its mirror image – called an anti-particle – which holds the opposite electrical charge. When particles and anti-particles collide, they annihilate each other in a small flash of energy. Since then, physicists have wondered why the universe seems to be dominated by matter and not antimatter. If everything were equal at the birth of the cosmos, matter and anti-matter would have existed in the same quantities. The observable universe would have had no chance of coming into being, as these opposing particles would have wiped each other out.

Trapping anti atoms Technical Feat

Understanding why there is this huge imbalance presents a daunting technical challenge. Until now, experiments have produced anti-atoms, namely of hydrogen, but only in a free state. That means they instantly collide with ordinary matter and get annihilated, making it impossible to measure them or study their structure. In a paper published in the British journal Nature, a team at the European Organisation for Nuclear Research (CERN) in Geneva explain a method of snaring these so-called antihydrogen atoms.

Experiments conducted in its ALPHA laboratory found a way of using strong, complex magnetic fields and a vacuum to capture and hold the mirror-image particles apart from ordinary matter. Thousands of antihydrogen atoms have been made in the lab, but in the most successful experiment so far, 38 have been trapped long enough – one tenth of a second – for them to be studied.

For reasons that no-one yet understands, nature ruled out antimatter. It is thus very rewarding, and a bit overwhelming, to look at the ALPHA device and know that it contains stable, neutral atoms of antimatter. This inspires us to work that much harder to see if antimatter holds some secret.

Nano-Revolution: Exotic Materials could be Made!!

A material just one atom thick yet stronger than steel and a ‘mini-submarine’ that can deliver a payload of chemotherapy deep inside a tumour are among the discoveries being presented at Nano Israel 2010. The nanotech conference in Tel Aviv has attracted researchers from across the science world, united by their work with the very, very small. The 1,500 participants at the two-day meeting which ends next week include chemists, physicists and medical researchers, all working with tiny structures around the thickness of a cell wall.

Drugs with built in GPS System

Physicists are developing new materials by removing or adding to existing structures and nano-medical researchers are building new ways to deliver drugs. According to Researcher Dan Peer:

We are all working to be able to manipulate molecules at atomic level. Sometimes the drug is there, but it doesn’t operate in a targeted manner. In such cases, scientists are trying to find ways to build ‘GPS systems’ into the drugs so they travel directly to malignant cells or inflammation.

Peer is trying to find out how to more effectively target cancer and the inflammation associated with diseases like multiple sclerosis by better directing toxic treatments like chemotherapy.

‘Therapeutic warheads’ to attack tumours

One way of doing that is to attach the cancer treatment to a vitamin that tumours happily suck up, allowing the medication to penetrate the malignant cells with ease. You can potentially create new materials, new vehicles for drugs, like very small bubbles, like mini-submarines, which carry them into the body.
Joseph Kost, a professor at Ben Gurion University of the Negev’s chemical engineering department, is working on a technique that delivers chemotherapy drug Cisplatin into tumours. The drug is carried by a tiny vessel through gaps of between 100-1000 nanometres in size, giving scientists a ‘therapeutic warhead’. Once inside, researchers irradiate the drug vehicles with ultrasound, causing them to ‘explode’ and disperse the treatment inside the tumour.Others are looking at ways to trick the body’s immune system to prevent it from identifying drug treatments as invading viruses and attacking them.

Elsewhere, physicists such as Andre Geim, winner of this year’s Nobel Prize for Physics, are using nanotechnology to develop new materials with a surprising range of applications. Geim, a Russian scientist workingin Britain, presented his work on graphene, a one-atom-thick slice of graphite that is stiffer than diamond. You can imagine you can make athousand devices out of this graphene. Graphene’s structure could even allow it to be used for faster DNA sequencing.

Solar cells mimicking photosynthesis

For Israel, hosting the gathering of nano-researchers is a way of showcasing a sector that the government is trying to foster. INNI works to match Israel’s nanotech researchers with private industry. A recent project saw Jerusalem-based company 3G Solar work with scientists at Bar Ilan University to develop a solar cell that processes energy ina similar way to photosynthesis in plants.

Aharon Gedanken, a professor of chemistry at Bar Ilan University, isusing nanotechnology to develop sterile hospital sheets and robes using a technique called sonochemistry. The process uses a chemical reaction that produces ‘microjets,’ which throw out nanoparticles of anti-bacterial metals like zinc oxide at “such a high speed that they are embedded in the surface. The resulting fabric can be washed, even at the hospital standard of 92 degrees Celsius, without losing its anti-bacterial properties. The vision of this project is that in the future all the fabrics in a hospital will be anti-bacterial.

Alarming Slowing in Winds Could Lessen Efficiency of Wind Turbines!!

Increasing amounts of vegetation could be causing up to 60% of a slowing in wind speed across the Northern Hemisphere, according to researchers analyzing three decades of wind-speed data in Nature Geoscience today.The decline is a potential concern for wind-turbine efficiency. But researchers can’t tell whether the effect, an average 10% slowdown, will make much difference to wind turbines; the slowing winds measured are are at 10 metres above the ground, whereas turbines operate at 50–100 metres up, where there is little global data. Several previous regional studies looking at the United States, Australia, China and parts of Europe have shown decreasing wind speeds just above the planet’s surface. Climate change, afforestation and urban development had been mooted as possible causes.

People always said the data were rubbish. There was no quality-controlled global archive of data. Researchers collected data from about 10,000 weather stations, although they removed all but 822 stations from their list because of incomplete records. That left records stretching back to 1979, taking in Europe, central Asia, eastern Asia and North America. Researchers expected a study spanning such a large area to show speeds increasing in some areas and decreasing in others. Annual wind speeds had declined at 73% of the stations, dropping by 5–15% over almost all of the land areas examined. The most pronounced effect was seen across Eurasia. The researchers also found that stronger winds have been affected more than weak ones.
Hot air and greenery

Changing patterns of atmospheric circulation at high altitudes have previously been blamed for slowing wind speeds- as air temperatures and pressures in different parts of the atmosphere shift with a gradually heating Earth. But Vautard and his team say that only 10–50% of the change they observed could be explained by current understanding of how changes in high-altitude circulation affect surface wind speeds. Another factor that has been suggested is thriving vegetation. More abundant and taller plants increase the ‘surface roughness’ of the ground, absorbing some of the wind’s energy and slowing it down. Surface roughness is a factor in climate models used by weather predictors such as the Met Office, but it had not been thought to effect wind speed over such a wide area. Increased vegetation-resulting from ex-agricultural land becoming overgrown, afforestation and changing landscape-management practices-could account for 25–60% of the observed stilling in wind speed, says Vautard. The researchers used satellite images to estimate increases in the volume and height of vegetation, and computer climate models to see how this would affect wind speed. Vautard said:

We need further investigation of whether afforestation affects wind speeds, but it’s almost certainly having an effect.

Final Answer?

Vegetation changes did not wholly explain wind-speed changes seen in eastern Europe and China. In central Asia the height of vegetation would have to have tripled to account for the stilling. Vautard admits this is “fairly unrealistic”. He suspects that changes in general atmospheric circulation may be more important in these parts of the world than in others. Golding says that changes in vegetation could explain the drop, but adds that increases in urban density, which would also absorb wind energy and increase surface roughness, could be having a similar effect. Vautard admits that urbanization could be an important factor, but says he and his team were unable to investigate its effects, because estimates to plug into computer models of how buildings affect surface roughness are not available.

[Source: Nature and Vautard, R., Cattiaux, J., Yiou, P., Thépaut, J.-N. & Ciais, P.Nature Geosci. advance online publication doi:10.1038/NGEO979(2010).]

Genetic Exchange is Millions Fold Faster in Sea

Chromosome swapping between marine bacteria is up to millions of times more frequent than thought and may blur the species lines. The process is known as horizontal gene transfer (HGT), asoppose to the ‘vertical’ swapping between generations from parent to offspring. The microbespack up random bits of chromosomes that are then transferred between individuals via a virus-like infection. Marine biologists observed the rate at which this occurs in the order Rhodo bacterales, and it was 650 000 to 31 million times greater than what was previously measured.

[Image Details:In the study, a group of Rhdobacter capsulatus were genetically marked with an antibiotic resistant gene. These modified strains were put with natural communities, and the resultant antibiotic resistance was then measured. Credit: Lauren McDaniel]
Watching Evolution in Action

Oceanic bacteria perform a range of important environmental functions that include greenhouse gas metabolism and the cycling of natural elements and molecules around the globe. Their amazing ability to perform diverse functions, teamed with an extraordinary resilience when faced with environmental threat, suggests a high incidence of adaptation is taking place. McDaniel who conducted this study said:

For me, the most exciting part about this project is that we are watching evolution in action. I have observed that scientists like to categorise things like bacteria and put them in neat little bins like ‘species A’ or ‘species B’ in order to potentially predict their behavior. While this may work for higher organisms, bacteria may actually exist more as a continuum than discrete species.

Gene Transfer

In the study, a group of Rhdobacter capsulatus were genetically marked with an antibiotic resistant gene. These modified strains were put with natural communities, and the resultant antibiotic resistance was then measured. The researchers were surprised to find such a rapid transfer of genetic information, which was 47% higher through direct transfer than through self moderated changes. Once the DNA is exchanged between individual bacteria it mingles with the host version and incorporates itself – similar tothe process that takes place in sexually reproducing animals when integrating DNA from both the mother and the father.

The widespread trait of horizontal gene transfer among bacterial communities may in fact be massively higher than currently estimated, and this may allow bacteria to take on new traits to enhance their fitness and capacity to deal with challenges. This finding adds to our appreciation of microbial adaptive capacities, illustrating a response by entire communities of bacteria not just individuals that are selected for or against during environmental change or need. How bugs adapt is so beautiful! And in this study we see it on a whole new level.
[Credit: CosmosMagazine]

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