title: Are some mutations directed?
abstract: A fundamental tenet of modern genetics is that mutations occur spontaneously, without regard to their effects on the organism's fitness. However, several authors have recently published evidence that suggests that the bacterium E. coli can respond to novel environmental conditions by inducing or directing specifically those mutations that enhance fitness in such environments. These claims of directed mutation have been met with alternative explanations for the reported observations.
authors.affiliation: Richard Lenski is at the Dept of Ecology and Evolutionary Biology, University of California, Irvine, CA 92717, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Lenski