16 | NewScientist | 7 December 2013

WE ARE a step closer to knowing how life began. For the first time, genetic information has been copied inside a simple cell designed to mimic primordial life.

To figure out how the first life on Earth formed from a collection of lifeless molecules, a team led by Jack Szostak at the Massachusetts General Hospital in Boston created “protocells” – bubbles of fatty acids that can carry RNA, thought

to be DNA’s precursor. The next step is to get the RNA to replicate.

RNA can copy itself using a mix of nucleotides, with the help of magnesium ions. But in Szostak’s protocells, the ions reacted with the fatty acids and destroyed the cells.

Looking for a way around this, Szostak’s team added various chemicals to the protocell and magnesium cocktail. They found

Electro-bugs burp methane emissions

FROM cow burps to melting permafrost, the greenhouse gas methane is produced in a myriad of ways. Now we can add another: bacteria that make electricity.

The methane produced by Methanosaeta, a microbe living in waste water, was thought to come from the breakdown of chemicals made by neighbouring bacteria. One of these, called Geobacter, has a talent of its own: the bugs shuttle electrons between one another using threadlike projections.

But when Amelia-Elena Rotaru at the University of Massachusetts, Amherst, grew both groups together, she found no methane was made if Geobacter was genetically engineered to lack the threads. It suggests Methanosaeta uses electrons from Geobacter to convert carbon dioxide in the air to methane – a finding that may help us control the release of the gas (Energy and Environmental Science, doi.org/p87).

Hypnotic whirling dervishes rely on hurricane physics

IF YOU’VE seen a whirling dervish, you may have been reminded of a hurricane. It turns out that the skirts of these dancers are buffeted by the same physical force.

Dervishes are Sufi Muslims whose whirling, ritual dance has become a tourist attraction in places such as Istanbul in Turkey. James Hanna at Virginia Tech in Blacksburg and his colleagues wanted to understand the science behind the dervishes’ mesmerising skirts.

In particular, a skirt can take on the shape of a triangular-based pyramid with its apex near the dancer’s midriff. The material forms three gently concave faces,

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Look to lemons to ignite spark of life that citrate, a derivative of the citric acid found in lemons, stabilises the cells while still allowing the RNA to copy itself (Science, doi.org/p86)

It is not known whether citrate existed on Earth 4 billion years ago when the first life arose. But Ramanarayanan Krishnamurthy of the Scripps Research Institute in La Jolla, California, who wasn’t involved in the work, says similar molecules certainly did form then, and might have done the job.

separated by three remarkably sharp ridges.The team ignored complexities such as gravity, and

built a model that considered only the inertia and tension of the material. Despite this, they found they could recreate the pyramidal shapes – but only if their simple model took into account the Coriolis force.

This force affects objects moving on the surface of a rotating body, for example generating hurricanes in Earth’s atmosphere as it moves over our spinning planet. The researchers say that a Coriolis force occurs when the skirt flows over the slowly rotating pyramid, even though the pyramid is merely a shape and not a solid object (New Journal of Physics, doi.org/p8n). The model may be useful for calculating the stresses experienced by rotating components in machinery, says Hanna.

CRISS-CROSS patterns on the icy surface of Jupiter’s moon Europa could be a sign that the ocean beneath is friendly to life.

The patterns were previously attributed to tectonic forces exerted by Jupiter’s gravitational pull. Now Johannes Wicht of the Max Planck Institute for Solar System Research in Lindau, Germany, and colleagues have created a model of the convection currents in Europa’s subsurface ocean and found that this can reproduce the terrain (Nature Geoscience Letters, doi.org/p9h).

The model suggests that the ocean is hugely turbulent, with three strong ocean jets. This would benefit life because it would help shift nutrients from the sea floor into the ocean body.

Choppy alien sea looks life-friendly

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