Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Experimental Evidence of Bacterial Evolution

...sometime around the 31,500th generation, something dramatic happened in just one of the [twelve] populations – the bacteria suddenly acquired the ability to metabolise citrate, a second nutrient in their culture medium that E. coli normally cannot use...Something, he concluded, must have happened around generation 20,000 that laid the groundwork...Lenski and his colleagues are now working to identify just what that earlier change was, and how it made the Cit+ mutation possible more than 10,000 generations later.

Indeed, the inability to use citrate is one of the traits by which bacteriologists distinguish E. coli from other species. The citrate-using mutants increased in population size and diversity.

"...it's outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting," says Lenski.

Lenski's experiment is also yet another poke in the eye for anti-evolutionists, notes Jerry Coyne, an evolutionary biologist at the University of Chicago. "The thing I like most is it says you can get these complex traits evolving by a combination of unlikely events," he says. "That's just what creationists say can't happen.".

http://www.newscientist.com/article/dn14094-bacteria-make-major-evolutionary

I suspect this will change few minds (and in fairness, a single experiment with something as turgid as bacteria probably shouldn't) but it is very interesting. Thanks for posting it!

If by 'turgid' you mean 'complex', Mike', I would have to disagree. The fact that it's a very simple organism that reproduces at a phenomenal rate makes it ideal for this study. Even so, it's taken twenty years to reach this point. A single experiment, yes; but samples of the cultures have been taken at regular recorded intervals and preserved - very much like making incremental backup copies of different versions of an office document. That makes it a repeatable experiment in which the gradual changes in the DNA can be studied.

Nothing, however much proof is available, will change the doggedly ignorant and deluded minds of dedicated anti-evolutionists; but that's irrelevant to the work at hand. If the specific physical causes of such genetic changes can be well understood, then there is bountiful potential for the advancement of genetic engineering.

That's the turgid part! The system of 40,000+ generations of bacteria is pretty massive. Even just tracking and working with the data must be a chore.

And I do agree that this research has potential to be very helpful in implementing genetic engineering.

Yes, you have to hand it to these guys - two decades of caring for countless cultures and cataloging them as they come calls for credit (that's aliteration, isn't it )