Crayfish molecular systematics: using a combination of procedures to estimate phylogeny

The use of comparative methods to test evolutionary hypotheses has become more common at both the macro- and microevolutionary levels. The application of such techniques is especially troublesome at the interface of these levels because phylogenetic relationships are often difficult to estimate. The use of a technique developed to estimate intraspecific cladograms combined with more traditional methods of phylogenetic estimation can improve the estimate in data sets containing a range of diversity when the lower bound of the range approaches 0% divergence. For nucleotide sequence data from the 16S region of the mitochondrial DNA from 72 individuals representing 37 species, this combined-procedures approach improved the estimate of phylogenetic relationships using maximum-parsimony, maximum-likelihood, and neighbor-joining methods. The estimated trees were used to examine systematic hypotheses relating to the crayfish genus Orconectes and species relationships within the subgenus Proceri...