Ordination analysis of sequences included in the EzTaxon-e database. Complete sequence similarity matrices were generated from multiple sequence alignments (.1200 bp) and were converted to Jukes and Cantor distance matrices (Jukes & Cantor, 1969). Principal coordinate analyses were performed as previously described (Legendre, 1998). To reduce the computational cost of obtaining complete series of eigenvalues and eigenvectors, the power method algorithm was employed for approximating eigenvalues (Golub & van Loan, 1996). Three-dimensional ordination plots were generated from the resultant principal components using the R package