Then, as a result of a single mutation that created a specific advantage for the entire population of bacteria, the colony underwent a significant growth spurt over a relatively short period. Once a rare mutation came up with a better design, it took only about 200 generations for the competitive advantage of larger size to predominate in the population of E. coli. What controls the rate of evolutionary change is a question that his work promises to answer. We can create different environments and manipulate the mutation rate of bacteria by altering pathways that involve DNA repair. But bacteria aren't the only microorganisms in Lenski's menagerie.
Digital organisms have several advantages over bacteria.
We have previously published research on experiments that we did a couple of years ago using 250 different types of bacteria. With digital organisms, we were able to look at more than one billion different types. Another advantage of the digital bugs is more fundamental to an understanding of the process of evolution. All those are based on DNA, genes, and proteins. We're looking for the foundations of evolutionary change that are independent of DNA and what we recognize in organisms around us.