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Evolution: Scientists Grow 56,000 Generations in Lab to Watch
Last edited Thu Sep 27, 2012, 12:47 PM - Edit history (1)
Wouldn't it be great if scientists could climb into a time machine and travel back in history to observe thousands of generations of a single living creature to see how it evolved over many years?
It turns out they've done just that, and they returned with evidence that the evolution of life is far more complex than many had thought. Instead of a single mutation that gave the creature an advantage over its peers, it took several mutations, in a very precise order, for the creature to be able to digest something it could not have eaten before.
The result? The "creature," in this case, is Escherichia coli, a common bacteria found in the guts of most mammals, and its population exploded because of its new diet.
--snip--
So over the last 24 years, Lenski and his colleagues have studied the bacteria through more than 56,000 generations. Samples are taken and frozen periodically, providing a fossil record all the way back to when Lenski started out with a single ancestor.
"Freezing doesn't kill bacteria, like it does humans or zebras," Blount said. "We can thaw them out and put them in a growth medium and grow the bacteria up again."
That provides a record of evolutionary changes back to the beginning of the experiment, and a few years ago, Lenski's team discovered something odd.
http://abcnews.go.com/Technology/evolution-action-michigan-state-scientists-grow-coli-56000/story?id=17329160#.UGRuixhpu5t
It turns out they've done just that, and they returned with evidence that the evolution of life is far more complex than many had thought. Instead of a single mutation that gave the creature an advantage over its peers, it took several mutations, in a very precise order, for the creature to be able to digest something it could not have eaten before.
The result? The "creature," in this case, is Escherichia coli, a common bacteria found in the guts of most mammals, and its population exploded because of its new diet.
--snip--
So over the last 24 years, Lenski and his colleagues have studied the bacteria through more than 56,000 generations. Samples are taken and frozen periodically, providing a fossil record all the way back to when Lenski started out with a single ancestor.
"Freezing doesn't kill bacteria, like it does humans or zebras," Blount said. "We can thaw them out and put them in a growth medium and grow the bacteria up again."
That provides a record of evolutionary changes back to the beginning of the experiment, and a few years ago, Lenski's team discovered something odd.
http://abcnews.go.com/Technology/evolution-action-michigan-state-scientists-grow-coli-56000/story?id=17329160#.UGRuixhpu5t
On edit: the above link may not work so try this---> http://www.redorbit.com/news/science/1112697558/evolution-e-coli-genome-analysis-092012/
SCIENCE!!!!!!!
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