E.Coli can now metabolize citrate. Actually, one specific colony at Michigan State can.
For the past 20 years, Richard Lenski has been keeping 12 separate colonies of E.Coli alive in a petri dish. Every 500 generations, he freezes a sample, in order to stop their growth. Recently, one of the colonies has developed the ability to metabolize citrate, one of two nutrients in their substrate. This is important, because until now, E.Coli can not metabolize citrate. In fact, this is one of the distinguishing characteristics of E.Coli. Now after 31,500 generations, it can. This ability developed after many simple natural random changes to the E.Coli genome. Examining the
saved cultures, it was determined that the critical change occurred somewhere around the 20,000th generation.
The take away: Someone has watched evolution occur.
Take that Mike Seaver.