Genomic and phylogenetic perspectives on the evolution of prokaryotes.

Prokaryotes have been at the forefront of the genome sequencing revolution. Many genomes have been completely sequenced, revealing much about bacterial and archaeal genome content and organization. Yet, a meaningful evolutionary picture of prokaryotes still eludes us. Much of the problem lies in understanding the mode and tempo of genome evolution. Here phenylalanyl-tRNA synthetase is used as an example of the complex interplay among lateral gene transfer, operon recombination, and gene recruitment in the evolution of some prokaryotic genes. Promising new approaches to genomic analyses, which could add to our understanding prokaryotic evolution and help in their classification, are discussed.