Resumen
- Bacteria genomes are small, ranging from 100 to 15 000 kb in length, but they harbor a vast reservoir of genetic and physiological diversity. Research initiated over 50 years ago began characterizing many features of bacterial genomes – their sizes, their structures, their contents – but until large numbers of sequenced bacterial genomes became available, it was difficult to establish the principles guiding their organization and evolution. Through comparative analyses involving thousands of sequenced bacterial genomes, we have gained broad knowledge of the variation within and among bacterial genomes, and have elucidated the processes that contribute to their dynamics.