Bacteria make major evolutionary shift in the lab (metabolise citrate)

[BadgerKid]

Twenty years ago, evolutionary biologist Richard Lenski of Michigan State University in East Lansing, US, took a single Escherichia coli bacterium and used its descendants to found 12 laboratory populations.

The 12 have been growing ever since, gradually accumulating mutations and evolving for more than 44,000 generations, while Lenski watches what happens.

But sometime around the 31,500th generation, something dramatic happened in just one of the populations – the bacteria suddenly acquired the ability to metabolise citrate, a second nutrient in their culture medium that E. coli normally cannot use.

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.

The replays showed that even when he looked at trillions of cells, only the original population re-evolved Cit+ – and only when he started the replay from generation 20,000 or greater. Something, he concluded, must have happened around generation 20,000 that laid the groundwork for Cit+ to later evolve.

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.

http://www.newscientist.com/channel/life/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html

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And I, for one, welcome our citrate-devouring overlords....

[Olney Blue]

1. Very interesting! Thanks for posting.

[rusty quoin]

2. You may love the citrate -devouring overlords, but creationist won't.

"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."

[Jackpine Radical]

7. That... THING... pictured in your post

with the blue tie is one of the best arguments I've ever seen against intelligent design.

[rusty quoin]

8. I have gotten many posts about that thing, and you are right.

There is nothing about intelligent design to justify it.

[ret5hd]

3. whats 2 to the 44,000 power? Man, thats one hella lot o' e. coli !!!

[Crunchy Frog]

4. Evidence for creationism. A divine intervention has been observed in the laboratory!

:bounce:

[madrchsod]

5. my niece is just starting her career in that field......

[Maine-i-acs]

6. Great! Now please breed one that eats Uranium ... or ...

Dioxin
C02
PCBs
etc...

[BadgerKid]

9. Bacteria That Degrade PCBs Identified

Researchers have identified a group of bacteria that can detoxify a common type of polychlorinated biphenyls (PCBs), which have contaminated more than 250 U.S. sites, including river and lake sediments.

http://www.physorg.com/news94315326.html

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I believe the umbrella term is bioremediation ( http://en.wikipedia.org/wiki/Bioremediation )

[ret5hd]

10. I hope you understand why...

there is a big difference between "eating" uranium and "eating" dioxin, etc.

(hint: dioxin,etc are compounds and "eating" them means breaking them into the constituent elements or other less harmful compunds. On the other hand, uranium is an element...there is nothing to "eat" it into...it will remain uranium until it decays. Now, if you are talking about finding a bacteria that somehow magically increases the rate of decay of uranium...well, good luck on that one.)