High life

due to draw-down, fears associated with declining grain yields over time, rising oil prices (which directly impact the cost of fertilizer, irrigation and transportation), hoarding (which always forces prices up), and kneejerk policy reactions from numerous governments around the globe who normally claim to be committed to free trade — what they did was suspend exports, make non-market (secret) deals at fixed prices, and also subsidize consumers,” he said. “Each of the latter reactions to price increases contributed in various ways to raising prices, and fears, still further on global markets. Policies supporting biofuels are part of the equation, but only one part.” Such comments make it clear that we should be cautious in attributing price increases simply to the diversion of grains to biofuel production. Webb also questions whether more of the world’s hungry would be adequately fed if biofuels were done away with, asking, “Is ‘diversion’ for fuel the only issue? If not used for biofuel, how exactly would that maize be used? To enable Haitians to eat better? I doubt it. Two major uses of maize are a) feed for livestock, to generate steaks and milk for affluent consumers, and b) processing into high fructose corn syrup, which now finds its way into almost every conceivable processed/ packaged product. Just having more maize available for food does not in itself allow the poor to access that food.” Assuming that current trends of meat consumption continue, the biofuel industry doesn’t seem to pose a major threat to corn demand as one of the main by-products of ethanol production are distiller’s grains, which are sold as a high-protein feed on the market. So, perhaps the debate should be reframed around the question of how we eat. At the recent international conference on climate change in Copenhagen, musician Sir Paul McCartney and scientist Rajendra Pachauri, the chairman of the 2007 Nobel Peace Prize-winning Intergovernmental Panel on Climate Change, both lobbied for reduced meat consumption as a way to mitigate damage to the environment linked to meat production. McCartney urged meeting attendants to abstain from meat for one day of the week. Implemented on a large scale, such modest measures could potentially have an enormous impact. Fifty years ago, when Frank Drake first tuned his radio receivers to eavesdrop on possible signals from distant civilisations, he did so in secret for fear of being ridiculed and losing his funding. Last month, as he addressed a discussion meeting opening the celebrations of the 350th anniversary of the Royal Society, he could survey a field much improved both by technological progress and by discoveries of potential habitats. A unifying biological theme, the search for a ‘second genesis’, has emerged for the study of astrobiology. As NASA researcher Chris McKay told the Royal Society meeting, researchers want to find a second kind of life in the Universe, because two examples are more powerful than one, and because they could then compare and contrast both types to find out which aspects of biology are due to chance and which to necessity. Perhaps the most spectacular progress is the discovery of more than 400 extrasolar planets in the last 15 years, as reviewed by Michel Mayor who was involved in the first such discovery back in 1995. Proving that planetary systems are commonplace and surprisingly diverse, this work has opened up the realistic chance of finding Earth-like planets orbiting other stars. With complementary methods including Doppler shift (as used for the first discovery), gravitational microlensing, and transit observations, researchers can now detect a broad range of extrasolar planets, down to Neptune-sized objects and even ‘super-Earths’ with less than 10 times the mass of our planet. Finding life on such planets would, however, depend on the other life forms being advanced enough to communicate across space, which is where Drake’s continued work at the SETI Institute comes in. Drake pointed out that the combined sensitivity of Earth’s receivers has improved by 14 orders of magnitude since he started listening out to space. However, he also admitted that efficiency improvements in our own communications technology have dimmed our radiowave emissions significantly, which means that the searches conducted since the 1960s may have dramatically overestimated the radio output of distant civilisations. Separate life forms would be easier to analyse if they turned up in our own solar system, although the odds against their existence are necessarily higher than for the Universe as a whole. Mars is the obvious first call for astrobiologists in our neighbourhood, although McKay warned that the exchange of meteorites between Earth and Mars mean that Martian life we may find could turn out to be closely related to our own kind, and not of a distinct origin. For a truly separate ‘second genesis’, McKay favours Saturn’s moon Enceladus, where, according to results from the recent Cassini mission, all requirements for the origin of life are met. Colin Pillinger from the Open University, who led the development of the analytical instruments of the doomed Beagle II lander, pointed out that the surprising detection of large quantities of perchlorate in Martian soil by the Phoenix lander invalidates the conventional ways of detecting organic molecules on Mars. Recent evidence of past water and present methane on the Red Planet has added to the excitement over possible subsurface microbes that may still await their discovery. Even closer to home, but still far out in a different way, is the new research project of physicist and popular science author Paul Davies, who has secured funding to look for an as yet undiscovered or unrecognised second genesis in extreme habitats on Earth. Many scientists (including Darwin) have argued that the runaway success of our own brand of life must have blown all other contenders away, even if there were parallel origins. Davies counters with the fact that we still don’t know much about the large majority of microorganisms that happen to be unculturable and may be missing out on life forms that are different enough to escape our detection methods. The race is on to find a second form of life in the Universe, be it under our feet or among the stars.