To determine the significance of differences between clonal libraries of en
vironmental rRNA gene sequences, differences between homologous coverage cu
rves C-X(D), and heterologous coverage curves, C-XY(D), were calculated by
a Cramer-von Mises-type statistic and compared by a Monte Carlo test proced
ure. This method successfully distinguished rRNA gene sequence libraries fr
om soil and bioreactors and correctly failed to find differences between li
braries of the same composition.