Unpacking the past: Identifying a key evolutionary step in E. coli metabolism
(Phys.org) —Evolution is a process that takes place over long periods of time over which genetics and ecology may interact, producing novel phenotypic traits. Researchers previously found that after roughly 31,500 generations had passed in a laboratory evolution experiment a rare metabolic innovation emerged in which Escherichia coli developed the ability to metabolize citrate (Cit+) in its growth medium. Through genetic analysis with a recursive genomewide recombination and sequencing method (REGRES), scientists at University of Texas, Austin have now identified a key mutation that they say demonstrates how improvement of an emergent trait can be as important to its eventual success as earlier mutations or environmental conditions that may have been necessary for it to initially evolve.