A false-colored image from fluorescence microscopy of a growing colony of E coli cells. Taken from "Aging and Death in E. coli" Citation: (2005) Aging and Death in E. coli. PLoS Biol 3(2): e58 doi:10.1371/journal.pbio.0030058 the discussion of a research paper by Stewart EJ, Madden R, Paul G, Taddei F (2005). "Aging and death in an organism that reproduces by morphologically symmetric division". PLoS Biol. 3 (2): e45. PMID 15685293.