Scientists to Resurrect Ancient Gene to Replay Evolution

[Gawdzilla Sama]

Scientists to Resurrect Ancient Gene to Replay Evolution

Michael Schirber
Astrobiology Magazine
LiveScience.com michael Schirber
astrobiology Magazine
livescience.com – Sun May 3, 11:10 am ET

The movie "Jurassic Park" was a lesson in how resurrecting extinct organisms can go awry. A new project plans to take a safer route: resurrect a single gene from an extinct species of bacteria. This tiny snippet of DNA will be implanted in modern-day bacteria, with the goal of seeing whether evolution can be replayed in the lab.

In previous work, paleogeneticist Eric Gaucher from the Georgia Institute of Technology and his colleagues reconstructed earlier forms of a common gene by computing the way different lineages diverged to create the bacterial family tree.

"It is a bit like what historical linguists do when they infer the spelling or pronunciation of an ancient word from its modern derivatives," Gaucher says. "Except, we are working with the DNA alphabet."

As part of NASA's Astrobiology: Exobiology and Evolutionary Biology program, Gaucher and Betul Kacar, also from Georgia Tech, now plan to plug one of their reconstructed genes in a modern organism's DNA.

If this genetic anachronism evolves forward along one of the branches that the researchers have computed, then this will provide some verification of this molecular genealogy technique, as well as give support to the notion that evolution is repeatable and not simply a matter of chance.

(Balance of article at link above.)

[Xamonas Chegwé]

I didn't quite get this one at first.

I originally thought: Why should the 'evolution' of this ancient gene follow the same pattern that they have calculated it did in the past? Surely, if evolutionary theory is to be accepted, that would require an identical set of external pressures, identical populations exhibiting identical genetic variation and identical random mutations?

Having read the rest of the original article, I can see that they are duplicating the evolutionary stress by implanting a gene that functions better at higher temperatures than those preferred by the organism. As this gene produces an essential protein, any mutations that allow the gene to function at a lower temperature will impart a definite advantage to the E. coli and should be selected for in subsequent generations.

It is a clever experiment. I look forward to the results with interest, as it will shoot the fundie argument about there being no 'proof' for evolution down in flames.

[Trolldor]

I didn't quite get this one at first.

I originally thought: Why should the 'evolution' of this ancient gene follow the same pattern that they have calculated it did in the past? Surely, if evolutionary theory is to be accepted, that would require an identical set of external pressures, identical populations exhibiting identical genetic variation and identical random mutations?

Having read the rest of the original article, I can see that they are duplicating the evolutionary stress by implanting a gene that functions better at higher temperatures than those preferred by the organism. As this gene produces an essential protein, any mutations that allow the gene to function at a lower temperature will impart a definite advantage to the E. coli and should be selected for in subsequent generations.

It is a clever experiment. I look forward to the results with interest, as it will shoot the fundie argument about there being no 'proof' for evolution down in flames.

It''s already been replicated/demonstrated in the lab by an artificial selective pressure - they disabled part of the flagellum and moved the food source of the bacteria away - it used a completely unrelated gene in order to restore the flagellum. The article was on RD.net quite a while ago, can't find it anymore unfortunately.