Photographs of the 12 long-term lines on 25 June 2008
(Above) Photograph of the long-term evolution experiment taken on 25 June 2008. Each flask harbors one of the 12 evolving populations. The photo was taken about 24 h after the cultures were serially transferred, hence they are at stationary phase. The populations grow in DM25 medium, which contains a relatively low glucose concentration so that the culture is not very turbid. However, one population, designated Ara-3, evolved to use the citrate that is also present in the medium. It has a much greater density of cells than the others, and it is therefore much more turbid, owing to the high concentration of citrate in the medium. (Below) A close-up view showing the Ara-3 population and two others. [Photos courtesy of Brian Baer and Neerja Hajela.]
