Maximum likelihood (ML) tree of algal 18S rDNA sequences from egg masses of four amphibian taxa from various North American localities.

<p>The data matrix included 1,653 characters and 180 sequences. Newly obtained sequences are bold-faced. ML and MP bootstrap values greater than 50% are shown at corresponding nodes. Subclades I−IV are collapsed into triangles for visual clarity; an un-collapsed version of the tree can be found as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108915#pone.0108915.s003" target="_blank">Figure S1</a>. Numbers in parentheses indicates the number of sequences obtained and analyzed for the corresponding sample. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108915#pone-0108915-t001" target="_blank">Table 1</a> for naming conventions and GenBank accession numbers.