(NWWB) - On 15 February 2013, asteroid 2012 DA14 missed earth by a mere 27,700 kilometers. This ancient 130,000 ton asteroid, spanning 45 meters in diameter, would have released the same amount of energy as a detonating 2.5 megaton atomic bomb, had it collided with the earth. It looks like 15 February 2013 was global meteor day, as a 9 ton behemoth caused widespread panic and injuries as it seared through the sky above Chebarkul, a town in central Russia. Not really cataclysmic, these events, but certainly significant enough to put the thought of mass extinction into our minds. Not only humans (and don’t forget the dinosaurs) are subject to mass extinction. Micro-organisms are intimately sensitive to changes in their environment. Take a tank of fermenting must. The savvy winemaker will manipulate this very complex environment to suit his and the fermenting yeast’s specific needs, but under certain conditions the yeast population can very quickly become extinct.