Analysis of 16S ribosomal RNA from samples of the bacterial groupProchlorococcus (a component of phytoplankton) shows that closely related Prochlorococcus populations that are genetically adapted to different levels of light coexist. This technique has been used to study genetic diversity in samples that are difficult to culture in the laboratory. But the technique is not perfect and leads to a tendency to group together organisms that appear very similar genetically but may be different physiologically — such as the Prochlorococcusecotypes.
- Jed A. Fuhrman
- Lisa Campbell
