Evolution is an on-going process.  Therefore, it can be studied experimentally in organisms with suitably short generations.  To that end, we have propagated 12 populations of E. coli in a simple environment for over 50,000 generations.  Two goals of this long-term experiment are to examine the repeatability of evolution and to characterize the dynamics of evolution.  We have quantified the extent of adaptation by natural selection, identified many examples of parallel evolution, and observed the origin of a function that transcends the usual definition of E. coli as a species.  We have used new technologies to sequence whole genomes to find all of the mutations present in temporal series of clones from some populations.  These genomic data provide new insights into the coupling of phenotypic and genetic evolution, and into the role of complex mutations in the emergence of key innovations.