Scientists Splice 500-Million-Year-Old Gene To See How It Evolved

The process is called Paleo-experimental evolution. (Photo : Georgia Institute of Technolog)

It's no Jurassic Park, but scientists have found a way to essentially rewind the clock and watch evolution play out before their very eyes. A team at the Georgia Institute of Technology has resurrected a 500-million-year-old gene from bacteria and spliced it into modern day Escherichia coli (E. coli) bacteria.

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The bacteria has now been growing for over 1,000 generations, and allows scientists to see how the gene possibly evolved half a billion years ago. This would give scientists a better understanding of evolutionary trajectories.

"This is as close as we can get to rewinding and replaying the molecular tape of life," said scientist Betül Kaçar, a NASA astrobiology postdoctoral fellow in Georgia Tech's NASA Center for Ribosomal Origins and Evolution. "The ability to observe an ancient gene in a modern organism as it evolves within a modern cell allows us to see whether the evolutionary trajectory once taken will repeat itself or whether a life will adapt following a different path."

The scientists chose to work with the gene Elongation Factor-Tu (EF-Tu), an important protein for E. coli. These types of proteins are found in bacteria, all cellular life, and essential for bacteria to survive. It is the protein's vital role that made this gene attractive to the researchers.

The researchers recreated the gene and created eight identical strains to see how the bacteria would adapt.

"The altered organism wasn't as healthy or fit as its modern-day version, at least initially," said Gaucher. "And this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day."

After 500 generations, the researchers found that the bacteria adapted quite well, reaching modern-day fitness levels and in some cases, even surpassing it.

The gene itself did not mutate, but rather the bacteria began interacting with the proteins in a different manner.

"We think that this process will allow us to address several longstanding questions in evolutionary and molecular biology," said Kaçar. "Among them, we want to know if an organism's history limits its future and if evolution always leads to a single, defined point or whether evolution has multiple solutions to a given problem."