The once rare brown argus butterfly is on the move........

The once rare brown argus butterfly is on the move, expanding its range and numbers in the U.K.—and it’s all thanks to climate change.Thus far, the world’s climate has warmed roughly 0.8 degree Celsius over the course of the last century or so, thanks to a rise in greenhouse gas concentrations now approaching 400 parts-per-million. With that amount of warming, biologists expect some species ranges to expand and others to contract but, thus far, many wily animals and plants have been confounding scientists’ expectations. In some cases, species that favor a warmer climate have actually retreated (think: lizards or amphibians). Or others have expanded even faster than the climate has warmed (think: tree species moving up a mountain slope).Obviously climate change isn’t the only factor in play. Habitat loss and disease seem to be dooming many varieties of amphibian while plants may be benefiting from human help (carried along on our own fossil fueled travels by car or plane).But for the brown argus butterfly with its trademark orange and white spots near its wingtips, climate seems to play a key role. It has spread northwards nearly 80 kilometers in just the last two decades, according to the U.K. Butterfly Monitoring Scheme. Warm summers have allowed the butterfly to begin using a new type of plants—such as the dove’s foot cranesbill—as a host in the U.K., the way it does in continental Europe. In prior decades, the butterfly had restricted itself to the rockrose.

That appears to be a result of the cooler climate back then. The long-lived and relatively sprawling rockrose plant allows for more stable populations of the butterfly when times are tough because of cool weather. It hosts the caterpillars on the underside of leaves on south-facing (and therefore sun-warmed) hillsides. But when generally balmy summers abound, as recently, the annual cranesbill can help the brown argus butterfly expand its range, according to new research to be published inScience on May 25.Of course, this expansion in the north is counterbalanced by a loss of habitat further south, where conditions are rapidly becoming too hot for the butterfly. “The picture across its whole distributional range in Europe looks somewhat different,” notes ecologist Oliver Schweiger of the Heimholtz Centre for Environmental Research in Halle, Germany, who was not involved in the research. His modeling work suggests that, even assuming the butterfly can fly past any natural features that might otherwise restrict range expansion, “large range retractions in the South cannot be counterbalanced by the expansions in the North.” And even flying animals, like butterflies and birds, can’t seem to keep pace with the poleward march of temperature bands, according to Schweiger’s work.

Nevertheless, this kind of adaptation to a changing climate may offer hope for other species. “Not all species must necessarily suffer from climate change,” Schweiger adds. “Showing that an extension of the utilizable host plants is possible and can help to cope with the consequences of climate change can be considered as good news.” In other words, don’t underestimate a species’ ability to adapt and make the best of it.

Image: Courtesy of Louise Mair

About the Author: David Biello is the associate editor for environment and energy at Scientific American. Follow on Twitter @dbiello.

Article in scientificamerican

The oldest-known musical instrument in the world.

A team led by Prof Tom Higham at Oxford University dated animal bones in the same ground layers as the flutes at Geissenkloesterle Cave in Germany's Swabian Jura.Prof Nick Conard, the Tuebingen University researcher who identified the previous record-holder for oldest instrument in 2009, was excavator at the site.He said: "These results are consistent with a hypothesis we made several years ago that the Danube River was a key corridor for the movement of humans and technological innovations into central Europe between 40,000-45,000 years ago.

The flutes, made from bird bone and mammoth ivory, come from a cave in southern Germany which contains early evidence for the occupation of Europe by modern humans - Homo sapiens.Scientists used carbon dating to show that the flutes were between 42,000 and 43,000 years old.The findings are described in the Journal of Human Evolution.


"Geissenkloesterle is one of several caves in the region that has produced important examples of personal ornaments, figurative art, mythical imagery and musical instruments."Musical instruments may have been used in recreation or for religious ritual, experts say.And some researchers have argued that music may have been one of a suite of behaviours displayed by our species which helped give them an edge over the Neanderthals - who went extinct in most parts of Europe 30,000 years ago.

Music could have played a role in the maintenance of larger social networks, which may have helped our species expand their territory at the expense of the more conservative Neanderthals.The researchers say the dating evidence from Geissenkloesterle suggests that modern humans entered the Upper Danube region before an extremely cold climatic phase at around 39,000-40,000 years ago.Previously, researchers had argued that modern humans initially migrated up the Danube immediately after this event."Modern humans during [this] period were in central Europe at least 2,000-3,000 years before this climatic deterioration, when huge icebergs calved from ice sheets in the northern Atlantic and temperatures plummeted," said Prof Higham."The question is what effect this downturn might have had on the people in Europe at the time."


Courtesy:-BBC

Methane in Artic....

Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere.The methane has been trapped by ice, but is able to escape as the ice melts.Writing in the journal Nature Geoscience, the researchers say this ancient gas could have a significant impact on climate change.
Methane is the second most important greenhouse gas after CO2 and levels are rising after a few years of stability.There are many sources of the gas around the world, some natural and some man-made, such as landfill waste disposal sites and farm animals. Tracking methane to these various sources is not easy.But the researchers on the new Arctic project, led by Katey Walter Anthony from the University of Alaska at Fairbanks (UAF), were able to identify long-stored gas by the ratio of different isotopes of carbon in the methane molecules.Using aerial and ground-based surveys, the team identified about 150,000 methane seeps in Alaska and Greenland in lakes along the margins of ice cover.Local sampling showed that some of these are releasing the ancient methane, perhaps from natural gas or coal deposits underneath the lakes, whereas others are emitting much younger gas, presumably formed through decay of plant material in the lakes."We observed most of these cryosphere-cap seeps in lakes along the boundaries of permafrost thaw and in moraines and fjords of retreating glaciers," they write, emphasising the point that warming in the Arctic is releasing this long-stored carbon.

Rewritable memory encoded into DNA

The work involved in building the system is almost as notable as the achievement itself, says Drew Endy of Stanford University in California who led the work, which is published today in Proceedings of the National Academy of Sciences

Synthetic biologists have long sought to devise biological data-storage systems because they could be useful in a variety of applications, and because data storage will be a fundamental function of the digital circuits that the field hopes to create in cells.

DNA can be programmed to act as a biological data-storage device.

GLOWIMAGES.COM

Rewritable biological memory circuits have been made previously, for instance from systems of transcription factors, which can be used to shut gene expression on or off in a cell. In such systems, once the memory state of the circuit is set, it can be erased and encoded with a new memory state, as is done in everyday devices such as personal computers.

Endy’s group attempted to create a rewritable memory system by splicing genetic elements from a bacteriophage — a bacterium-infecting virus — into the DNA of the bacterium Escherichia coli.

The system consists of a stretch of DNA flanked by sites that signal to enzymes made by the bacteriophage, instructing them to cut out the DNA and paste it back into the chromosome in the reverse orientation. Endy’s group shows that the device can be set and reset repeatedly — up to 16 times. One advantage this system has over those using transcription factors is that it is truly digital, with forward and reverse orientations of the DNA acting like a '0' or a '1' in binary. Also, the cell expends no energy in storing the memory, beyond DNA maintenance, says Endy. He points out that combinations of such elements could be used to track cellular events, such as the series of cell divisions by which a stem cell becomes a differentiated adult cell.

“What Drew’s group can do that others haven’t demonstrated is the ability to cycle the memory element over and over, kind of like you can write a bit to a hard drive, read it and change it back over and over again,” says synthetic biologist Eric Klavins of the University of Washington in Seattle.

Debugging designs

Endy’s group chose a particular bacteriophage element for the work because it seemed to have the potential to reliably change the orientation of DNA. But that didn’t turn out to be the case. As a result, Jerome Bonnet, the postdoctoral student who spearheaded the project, spent three years tweaking the system to make it work, ultimately creating 750 different designs in his attempts to troubleshoot various aspects.

“It’s a pretty sad criticism of the state of technology in synthetic biology where we’re trying to program the expression of half a dozen genes and it takes 750 design attempts to get that working,” Endy says. “It’s like trying to write a six-line code on a computer that takes 750 debug attempts to work.”

Klavins agrees that many experiments in the field must go through extensive testing and tweaking processes before they achieve their goals. But he says that this is changing as the gene-synthesis tools that are needed to make new pieces of genetic circuitry become faster and cheaper.

“The cheaper and easier gene synthesis becomes, the more easily we’ll be able to do this kind of thing,” Klavins says.

Read more on Nature.com

Nature

 

doi:10.1038/nature.2012.10670

Faith and Belief

Philosopher Daniel Dennett was one of the stars of the Global Atheist Convention in Melbourne

Dr. Peter Boghossian's May 6th public lecture, "Faith: Pretending to know things you don't know"