||Bacteria Escherichia coli
||Lawrence JG, Ochman H. Molecular archaeology of the Escherichia coli genome.Proc Natl Acad Sci U S A. 1998 Aug 4 95(16):9413-7.PubMed ID9689094
||The availability of the complete sequence of Escherichia coli strain MG1655 provides the first opportunity to assess the overall impact of horizontal genetic transfer on the evolution of bacterial genomes. Researchers found that 755 of 4,288 ORFs (547.8 kb) have been introduced into the E. coli genome in at least 234 lateral transfer events since this species diverged from the Salmonella lineage 100 million years (Myr) ago.
||Although most of the acquired genes subsequently were deleted, the sequences that have persisted ( approximately 18% of the current chromosome) have conferred properties permitting E. coli to explore otherwise unreachable ecological niches.