Welcome Guest [Log In] [Register]
VVV REGISTER AN ACCOUNT VVV
Posted Image
^^^ CLICK THE RETARD BUTTON ^^^
It will make this annoying-as-fuck notice go away.

Username:   Password:
Add Reply
Take THAT creationists!; Evidence of evolution! (No, really)
Topic Started: Friday 13-06-2008, 23:35 (145 Views)
PyroLeprechaun
Member Avatar
Blithering Wiseman
http://www.newscientist.com/article/dn1409...s2_head_dn14094

Quote:
 
Bacteria make major evolutionary shift in the lab

* 22:00 09 June 2008
* NewScientist.com news service
* Bob Holmes

A major evolutionary innovation has unfurled right in front of researchers' eyes. It's the first time evolution has been caught in the act of making such a rare and complex new trait.

And because the species in question is a bacterium, scientists have been able to replay history to show how this evolutionary novelty grew from the accumulation of unpredictable, chance events.

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.
Profound change

Mostly, the patterns Lenski saw were similar in each separate population. All 12 evolved larger cells, for example, as well as faster growth rates on the glucose they were fed, and lower peak population densities.

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.

"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.
Rare mutation?

By this time, Lenski calculated, enough bacterial cells had lived and died that all simple mutations must already have occurred several times over.

That meant the "citrate-plus" trait must have been something special – either it was a single mutation of an unusually improbable sort, a rare chromosome inversion, say, or else gaining the ability to use citrate required the accumulation of several mutations in sequence.

To find out which, Lenski turned to his freezer, where he had saved samples of each population every 500 generations. These allowed him to replay history from any starting point he chose, by reviving the bacteria and letting evolution "replay" again.

Would the same population evolve Cit+ again, he wondered, or would any of the 12 be equally likely to hit the jackpot?
Evidence of evolution

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.

In the meantime, the experiment stands as proof that evolution does not always lead to the best possible outcome. Instead, a chance event can sometimes open evolutionary doors for one population that remain forever closed to other populations with different histories.

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."


>_>b
Edited by PyroLeprechaun, Friday 13-06-2008, 23:48.
Offline Profile Quote Post Goto Top
 
EstUmbra
Member Avatar
Lone Defender
I chose to believe what I was programmed to believe
Offline Profile Quote Post Goto Top
 
Legoroll
Member Avatar
Dr. Pepper
Hmmm...

I'm just gonna leave without saying anything more than this article proves nothing. Don't even want to get into it...
Offline Profile Quote Post Goto Top
 
RikusSexSlave
Member Avatar
Fuckin Hadoken
I'm not a creationist, trust me, but proving one instance of evolution doesn't prove its universal existence.
Offline Profile Quote Post Goto Top
 
Wakapanda Of Doom
Member Avatar
ONE OF THE ORIGINAL FUCKS
more than proof of evolution it means bacteria mutate and are getting new watys of surviving <_<
Offline Profile Quote Post Goto Top
 
Omgarm
Member Avatar
Troetelbeertje
It shows life forms, without much intellect, can adapt to their surroundings. While not confirming evolution completely it is coming closer.

Once one of the bacteria generations develops something more severe, like a penis or something, we're talking about actual proof...
Offline Profile Quote Post Goto Top
 
Judge Doom
Member Avatar
Supersoldier
I dont know how much it proves but it is interesting.
Offline Profile Quote Post Goto Top
 
Phazorn
Member Avatar
NOTHING
*sips Dr Pepper*
Offline Profile Quote Post Goto Top
 
Stockholm Syndrome
Member Avatar
Facesitter
And yet there's still monkeys.
Offline Profile Quote Post Goto Top
 
`roboteectoast
Member Avatar
ALL IRONS IRON IRON !
Omgarm
Saturday 14-06-2008, 06:45
Once one of the bacteria generations develops something more severe, like a penis or something, we're talking about actual proof...
E.Coli metabolizing citrate is actually pretty severe...<w<
Posted Image

E.COLI HAS MORE PENISES THAN YOU CAN HANDLE.


Why must Think Geek's shipping cost so much? ;___;
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
ZetaBoards - Free Forum Hosting
Free Forums with no limits on posts or members.
« Previous Topic · Wackapedia · Next Topic »
Add Reply

The Gamer Gateway