FIG. 2.

(A to D) Ratios of OTU numbers for the short pyrosequencing-simulating regions studied and OTU numbers for the nearly full-length fragment at the 3% (white), 6% (black), 8% (dark gray), 10% (light gray), and 15% (gray gridded) cutoffs in the Soil-Okla-A clone library (A), a clone library from trembling aspen soil (33) (B), a clone library from zebrafish gut (43) (C), and a composite clone library from the endolithic and epilithic communities inhabiting the ocean crust in the ocean floor in the East Pacific Ridge (45) (D). (E) Averages of the OTU ratios for the four clone libraries at the same taxonomic cutoffs.