Tag Archives: e coli

Evolution observed in laboratory bacteria

Image of E Coli in the labFor the first time, a major evolutionary change has been observed in laboratory conditions, giving even greater weighting to evolutionary theory. The bacteria used, a strain of E. Coli, was first introduced into the Michigan State University lab twenty years ago by evolutionary biologist Richard Lenski. Some 44,000 generations later, the bacteria are still reproducing.

Somewhere around the 31,500th generation, the E. Coli developed a trait not present in the original strain: they began to be able to metabolise citrate, the inability of which is one of the main ways scientists distinguish E. Coli from other bacteria. Importantly, the paper says that evolution occurs as a sum of the previous steps of mutation and that as this history varies between groups of creatures, evolution is a random and unpredictable act.

“It’s the most profound change we have seen during the experiment. This was clearly something quite different for them, and it’s outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting,” says Lenski.

One of the main criticisms of evolutionary theory has been that it is a theory that hasn’t been observed in the real world. Creationists are going to have a hard time explaining this result away, one suspects.

[via Daily Kos, image by scaliber001]