Two scientists say they have determined the complete genetic code of a free-living organism for the first time.

H. influenzae was the first free-living organism to have its entire genome sequenced.

The general trends of bacterial evolution indicate that bacteria started as free-living organisms.

This form of metabolism evolved early, and it is even possible that the first free-living organism was a methanogen.

It has been reported as free-living organism in marine mud and on algae.

Along with ureaplasmas, mycoplasmas are the smallest free-living organisms known.

Such relationships can exist at multiple time scales, which reflect the highly structural habitats of free-living organisms.

Discovered a century ago in plants, mycoplasmas are the smallest and simplest free-living organisms.

P. mirabilis is often found as a free-living organism in soil and water.

Yet now, for the first time, a free-living organism has been precisely defined by the chemical identification of its complete genetic blueprint.