Bacterial 'Evolution'

Well, I can't really let Darwin Day pass without saying something, and with the entire blogosphere going wild about it I thought I may as well jump on the bandwagon, so here's a quick review of an interesting article I read by Carl Zimmer:

"Zimmer absorbingly describes the work of Richard Lenski and his experiments with E-coli bacteria. One ancient (and also current) criticism of evolution/Darwinism is that as it supposedly takes place over millions of years, how can anyone say for sure if the principle is operating if no one can see it happen? Lenski's experiments have negated this by his bacterial experiments.

"E-coli is a common microbe in the human gut that survives by the consumption of sugar (glucose). Lenski wanted to observe what happened to the bacteria as it underwent continual feast and famine cycles. He kept records by periodically collecting samples of the mixture and freezing them. After a while one flask developed a change; E-coli needs trace amounts of iron to survive but cannot consume free iron atoms, and the mixture contains citrate (a compound that can bind iron atoms) which the E-coli can absorb but which the citrate cannot actually enter the microbe. In normal circumstances E-coli microbes also cannot consume citrate in the presence of oxygen. In this particular flask it was found that the E-coli was consuming the citrate. In other words, the E-coli bacteria had evolved into a type that could feast on the citrate and thus didn't have to starve when the glucose supply ran out!

"This was proof that the manipulation had generated a set of circumstances by which the original microbe mutated in order to adapt to it's new circumstance. By consulting his records of samples, he could determine that the mutation occurred after 31,000 generations but before 31,500 generations. The microbes continue to evolve."

More details in a special digimag of BBC Focus magazine to commemorate Darwin's bicentennial. It definitely represents a middle-finger in the Creationist direction. Other interesting articles discuss whether evolution is 'dead' - Steve Jones says 'yea' while PZ Myers says 'nay'.