Biologists at Georgia Tech have resurrected a 500-million-year-old gene from bacteria and inserted it into modern Escherichia coli (E.coli) bacteria. The researchers have observed the bacterium grow over more than 1,000 generations, allowing them to see "evolution in action".
In a process called paleo-experimental evolution,Betül Kaçar, a Nasa astrobiology postdoctoral fellow in Georgia Tech's Nasa Centre for Ribosomal Origins and Evolution, built on work by his advisor Eric Gaucher to take the ancient genetic sequence of the Elongation Factor-Tu (EF-Tu) protein -- one of the most abundant proteins in bacteria and required for bacteria to survive -- and inserting in the correct chromosomal order within modern E-coli. Kaçar produced eight identical strains and let the "ancient life" re-evolve. This chimeric bacteria survived, but grew about twice as slowly as its modern counterpart.
"This is as close as we can get to rewinding and replaying the molecular tape of life. 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," said Kaçar.