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4 BILLION years before present: the surface of a newly formed planet around a medium-sized star is beginning to cool down. It's a violent place, bombarded by meteorites and riven by volcanic eruptions, with an atmosphere full of toxic gases. But almost as soon as water begins to form pools and oceans on its surface, something extraordinary happens. A molecule, or perhaps a set of molecules, capable of replicating itself arises. This was the dawn of evolution.
Take note, DNA and RNA: it's not all about you. Life on Earth may have begun with a splash of TNA – a different kind of genetic material altogether. Because RNA can do many things at once, those studying the origins of life have long thought that it was the first genetic material. But the discovery that a chemical relative called TNA can perform one of RNA's defining functions calls this into question.
Read full article Continue reading page | 1 | 2 | 3 Life must have begun with a simple molecule that could reproduce itself – and now we think we know how to make one 4 BILLION years before present: the surface of a newly formed planet around a medium-sized star is beginning to cool down. It's a violent place, bombarded by meteorites and riven by volcanic eruptions, with an atmosphere full of toxic gases. But almost as soon as water begins to form pools and oceans on its surface, something extraordinary happens.
Simple oil drops show that if you get the conditions right, basic life may emerge almost fully formed WHEN Stanley Miller and Harold Urey created amino acids by shooting sparks through a "primordial atmosphere" of methane, ammonia, hydrogen and water, biologists thought a full understanding of the origins of life was within reach. Almost 60 years on from the most famous origin-of-life experiment of them all, we're still waiting. Could that be because biologists have been looking at the wrong part of the experiment?
FORGET antibiotics, let's try nanoparticles. That's according to DARPA , the US military's research arm, which says that rather than spend money on new antibiotics, which only work until bacterial strains grow resistant, "readily adaptable nanotherapeutics" can fight infection instead. The agency has called for proposals to find ways to use small interfering RNA (siRNA) to fight bacteria. These scraps of genetic code seek out their mirror image within cells, such as bacteria, and silence them. This stops protein production and leads to cell death. DARPA is seeking ideas for adaptable nanoparticles that can be "reprogrammed on the fly" by loading up specific siRNA to deal with outbreaks among troops.