Video: Electing a US President in Plain English. Every four years, Americans who are 18 or older have a big responsibility.
Our votes decide who becomes the president of the United States. Unfortunately the US election system isn't that simple. Bacteria make major evolutionary shift in the lab - life - 09 June 2008. A major evolutionary innovation has unfurled right in front of researchers' eyes.
It's the first time evolution has been caught in the act of making such a rare and complex new trait. And because the species in question is a bacterium, scientists have been able to replay history to show how this evolutionary novelty grew from the accumulation of unpredictable, chance events. Twenty years ago, evolutionary biologist Richard Lenski of Michigan State University in East Lansing, US, took a single Escherichia coli bacterium and used its descendants to found 12 laboratory populations. The 12 have been growing ever since, gradually accumulating mutations and evolving for more than 44,000 generations, while Lenski watches what happens.
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