It's a project 500 million years in the making. Only this time, instead of playing on a movie screen in Jurassic Park, it's happening in a lab at the Georgia Institute of Technology.
Using a process called paleo-experimental evolution, Georgia Tech researchers have resurrected a 500-million-year-old gene from bacteria and inserted it into modern-day Escherichia coli(E. coli) bacteria. This bacterium has now been growing for more than 1,000 generations, giving the scientists a front row seat to observe evolution in action.
"This is as close as we can get to rewinding and replaying the molecular tape of life," said scientist Betl Kaar, 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."
In 2008, Kaar's postdoctoral advisor, Associate Professor of Biology Eric Gaucher, successfully determined the ancient genetic sequence of Elongation Factor-Tu (EF-Tu), an essential protein in E. coli. EFs are one of the most abundant proteins in bacteria, found in all known cellular life and required for bacteria to survive. That vital role made it a perfect protein for the scientists to answer questions about evolution.
After achieving the difficult task of placing the ancient gene in the correct chromosomal order and position in place of the modern gene within E. coli, Kaar produced eight identical bacterial strains and allowed "ancient life" to re-evolve. This chimeric bacteria composed of both modern and ancient genes survived, but grew about two times slower than its counterpart composed of only modern genes.
"The altered organism wasn't as healthy or fit as its modern-day version, at least initially," said Gaucher
|Contact: Jason Maderer|
Georgia Institute of Technology