Bayesian and maximum likelihood analyses of rotifer-acanthocephalan relationships

Abstract

Rotifera is composed of groups with unusual ultrastructural, physiological, and reproductive characters. Our ability to understand the evolution of these features is complicated by the fact that the phylogenetic relationships among the three traditional rotifer groups (Seisonidea, Monogononta, and Bdelloidea) and Acanthocephala remain unresolved. Here, I present maximum likelihood and Bayesian analyses of rotifer–acanthocephalan relationships using both the protein-coding gene hsp82 and a combined data set of hsp82 and ribosomal small subunit (SSU) DNA sequences, using nucleotide and codon based models of evolution. Statistical analysis of the phylogenetic support for any of the likely relationships among rotifer groups suggests that more than a combined hsp82  + SSU data set will be needed to resolve rotifer–acanthocephalan phylogeny with any degree of certainty.