Phylogenetic Signal Dissection Identifies the Root of Starfishes

摘要: Relationships within the class Asteroidea have remained controversial for almost 100 years and, despite many attempts to resolve this problem using molecular data, no consensus has yet emerged. Using two nuclear genes and a taxon sampling covering major asteroid clades we show that non-phylogenetic signal created by three factors - Long Branch Attraction, compositional heterogeneity use of poorly fitting models evolution – confounded accurate estimation phylogenetic relationships. To overcome effect analyse data non-homogeneous models, site stripping creation subpartitions aimed reduce or amplify systematic error, calculate Bayes Factor support selection previously suggested topological arrangements orders. We most previous alternative hypotheses are not supported in reliable partitions, including placement either Forcipulatida Paxillosida as sister group other branches. The best-supported solution places Velatida asteroids, implications finding morphological asteroids presented.