Untangling the branches of evolution's past is a daunting enough task for researchers, but some scientists are now turning their eyes toward the future in a bid to predict evolution's course. Barry G. Hall, professor of biology at the University of Rochester, has shown how a model of evolution developed in the lab accurately reproduces natural evolution. The research, published in the March issue of Genetics, demonstrates how the model is so accurate that it can be used to predict how a strain of bacteria will become resistant to antibiotics-giving researchers a possible tool to create drugs to which bacteria cannot adapt.
"Antibiotic-resistant bacteria were a perfect target on which to test the model because we have examples of antibiotic resistance genes that first appeared 40 years ago," says Hall. "We know how those genes evolved in nature during the last 40 years, so if we apply the model to those genes and the model predicts those same evolutionary outcomes as happened in nature, we can be confident that the model works."
"Hall's recent work lays an all-important conceptual foundation for understanding the functional evolution of enzymes," says Anthony M. Dean, associate professor of biotechnology at the University of Minnesota. "Not only has he attempted to predict the outcome of adaptive evolution, but he has removed that last vestige of vitalism, which asserts that natural selection can only be studied in the natural environment."
Evolution is usually a very slow process. A mutation in the genetic code of an organism changes the organism's functions, usually for the worse, but sometimes for the better. Those organisms with mutations that allow them to thrive better than their cousins, tend to survive while the cousins die out. A classic example is to remove the gene that allows E. coli bacteria to digest lactose, but then give the colony of bacteria only lactose to eat. Of the millions in a colony, some bacteria re-evolve the ability to
Contact: Jonathan Sherwood
University of Rochester