Mitigating Anticipated Effects of Systematic Errors Supports Sister-Group Relationship between Xenacoelomorpha and Ambulacraria (Current Biology)

Philippe et al. use new genetic data to study the phylogenetic affinities of the Xenacoelomorpha, a group of simple marine worms. Tackling potential sources of error strengthens support for a relationship between Xenacoelomorpha and the more complex echinoderms and hemichordates. The simple Xenacoelomorpha probably evolved from a complex ancestor.