"Our collaborators isolated individual bacteria from a population that had evolved for 500 generations and sequenced their entire DNA genome to determine all the changes that had occurred," Cooper said. "By isolating these changes and adding them in defined combinations back into the original ancestral strain, we were able to determine their individual effects."
Reminiscent of Aesop's lesson that 'slow and steady wins the race,' Cooper adds that even bacteria can benefit from a long-term view, with their experiment showing that bacteria that adapted, slowly but consistently, outcompeted those that initially grew quickly but then ran out of ways to improve.
With much of his work based on experimental evolution, which is the lab-based study of evolving populations, Cooper's motivation for this experiment comes from wanting to understand the factors involved in evolution of organisms to better fit their environments. Using bacterial and computational experimental systems he aims to identify and integrate these mechanisms and examine how they depend on genetic and environmental factors.
"Bacteria provide an ideal model system to address these questions, because they evolve so quickly, undergoing thousands of generations in only a few years," Cooper said. "Additionally, we can now sequence their entire genomes and determine the genetic changes that lead to improvements in their ability to grow."
Funded by the National Science Foundation and the Defense Advanced Research Projects Agency, this work was a multidisciplinary effort done in collaboration with researchers in zoology, microbiology and molecular genetics at MSU. In addition to UH's Cooper and Shrestha, the MSU team consisted of Richard Le
|Contact: Lisa Merkl|
University of Houston