Time In A Bottle: Scientists Watch Evolution Unfold in Lab

[Caladan]

ScienceDaily (Oct. 19, 2009) — A 21-year Michigan State University experiment that distills the essence of evolution in laboratory flasks not only demonstrates natural selection at work, but could lead to biotechnology and medical research advances, researchers said.

Charles Darwin's seminal Origin of Species first laid out the case for evolution exactly 150 years ago. Now, MSU professor Richard Lenski and colleagues document the process in their analysis of 40,000 generations of bacteria, published this week in the international science journal Nature.
Lenski, Hannah Professor of Microbial Ecology at MSU, started growing cultures of fast-reproducing, single-celled E. coli bacteria in 1988. If a genetic mutation gives a cell an advantage in competition for food, he reasoned, it should dominate the entire culture. While Darwin's theory of natural selection is supported by other studies, it has never before been studied for so many cycles and in such detail.
"It's extra nice now to be able to show precisely how selection has changed the genomes of these bacteria, step by step over tens of thousands of generations," Lenski said.
Lenski's team periodically froze bacteria for later study, and technology has since developed to allow complete genetic sequencing. By the 20,000-generation midpoint, researchers discovered 45 mutations among surviving cells. Those mutations, according to Darwin's theory, should have conferred some advantage, and that's exactly what the researchers found.
The results "beautifully emphasize the succession of mutational events that allowed these organisms to climb toward higher and higher efficiency in their environment," noted Dominique Schneider, a molecular geneticist at the Université Joseph Fourier in Grenoble, France.
Lenski's long-running experiment itself is uniquely suited to answer some critical questions -- such as whether rates of change in a bacteria's genome move in tandem with its fitness to survive.
"The coupling between genomic and adaptive evolution is complex and can be counterintuitive," Lenski concluded. "The genome was evolving along at a surprisingly constant rate, even as the adaptation of the bacteria slowed down a lot. But then suddenly the mutation rate jumped way up, and a new dynamic relationship was established."
A mutation involved in DNA metabolism arose around generation 26,000, causing the mutation rate everywhere else in the genome to increase dramatically. The number of mutations jumped to 653 by generation 40,000, but researchers surmise that most of the late-evolving mutations were not helpful to the bacteria.
Gene mutations involved in human DNA replication are involved in some cancers. Many of the patterns observed in the experiment also occur in certain microbial infections, "and cancer progression is a fundamentally similar evolutionary process," observed collaborator Jeffrey Barrick. "So what we learn here can help us better understand the course of these diseases."
Barrick, a postdoctoral researcher in MSU's Department of Microbiology and Molecular Genetics, developed computational tools to discover and validate often complex mutations. "We know an astounding amount about the details of evolution in these little Erlenmeyer flasks," he said.
The Nature paper involved collaboration with scientists from South Korea as well as France and MSU. The research, said genomics team leader Jihyun Kim of the Korea Research Institute of Bioscience and Biotechnology, "is not only useful in understanding the tempo and mode of evolution, but can serve as a nice framework for practical applications in biotechnology, such as improving the performance or productivity of an industrial strain."
Thousands of generations later, the MSU experiment continues to evolve. "Like a lot of science, our study answers some questions but raises many others," Lenski said.
The research has been supported by the National Science Foundation and the Defense Advanced Research Projects Agency.

Source: Time In A Bottle: Scientists Watch Evolution Unfold

 

[MSizer]

Yup, Lenski hit the jackpot. His "12 tribes of E. Coli" experiments are nothing short of brilliant.

John Endler is another brilliant designer of experiments that have shown evolution in wild guppies.

Not to mention the lizards of the 2 islands off of croatia.

They're all examples of measurable (by naked eye) evolution in less than one human lifetime.

 

[Quiddity]

We knew this could happen.

I have no patience, bring the bird that turns into a lizard now!

 

[Vile Atheist]

But can he make a crockoduck?

 

[MSizer]

But can he make a crockoduck?

Don't forget the fronkey too. That's another devastating blow to the theory of evolution.

 

[tumbleweed41]

bring the bird that turns into a lizard now!

But that would be contrary to the ToE.

 

[DallasApple]

Time is always in some sort of bottle..

The old Turtle in the movie Kung Fu Panda said it..

"Yesterday is history"

Tomorrow is a mystery"

Today is a gift

Thats why its called present"


Love

Dallas

 

[Vile Atheist]

What if today sucks? Can I get a gift receipt?

 

[Nepenthe]

I love that Jim Croce song "If I Could Save 40,000 Generations of Bacteria Whose 26,000th Generation Caused the Mutation Rate In the Genome to Increase In a Bottle".

 

[Quiddity]

But that would be contrary to the ToE.

Bare with me, what is ToE?

 

[Vile Atheist]

Theory of Evolution.

 

[ManTimeForgot]

What sort of population constraints are there? Positive selection goes up as aggregate population goes up. I would be interested in knowing how correlated those two are in simple celled organisms. Also since there are space constraints does anyone suppose that the bacteria will "plateau" in terms of positive selection (unless they vary the food sources and environment from time to time)?

MTF

 

[DallasApple]

What if today sucks? Can I get a gift receipt?

Yes...the gift reciept of hope.(and bedsides that no one ever siad sometimes gifts dont seem to suck at first).

Anyway its all apparrntly in a bottle.

love

Dallas

 

[evolved yet?]

This argument holds no water because if there was a Croccoduck and a fronkey there would need to be a fronkey-croccoduck, evolution does not predict these sort of thing.

 

[Revoltingest]

I'd like to see a basil plant which also grows pine nuts & cured olives.
Single-source pesto in a blender!

 

[Autodidact]

This argument holds no water because if there was a Croccoduck and a fronkey there would need to be a fronkey-croccoduck, evoluion does not predict these sort of thing.

Which obviously would be called a fruckaduck. You may frubal me later.

 

[evolved yet?]

I looked at the article and it is actually twenty two years running now...

 

[Autodidact]

I love that Jim Croce song "If I Could Save 40,000 Generations of Bacteria Whose 26,000th Generation Caused the Mutation Rate In the Genome to Increase In a Bottle".

If life could evolve in a bottle,
if new species arose and they do,
we'd be where we are in reality,
and know evolution is true...