Discriminatory power of DNA barcodes.

<p>(A) Within-species genetic distances (within-site [red], between-site [blue]) ranked by magnitude. (B) The barcode gap expressed as the maximum within-species distance compared to the minimum between-species distance; line shows equal interspecific-intraspecific distances. The magnitude of intraspecific genetic distance is variable across species, but maximum intraspecific distance is almost always less than the minimum interspecific genetic distances. Distance modeled using the Felsenstein 1984 model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115750#pone.0115750-Felsenstein1" target="_blank">[50]</a>, which, using the IOTU classification, optimizes these data according to the Akaike Information Criterion. See supplementary documents for the same data modeled using Kimura 2-parameter and uncorrected <i>p</i> distances.