Evaluating the Impact of Anatomical Partitioning on Summary Topologies Obtained with Bayesian Phylogenetic Analyses of Morphological Data.

This article evaluates the impact of anatomical partitioning on Bayesian phylogenetic analyses of morphological data, focusing on its effects on tree topology precision and accuracy. Using simulations based on two empirical datasets and reanalyses of 32 vertebrate morphological datasets, the study finds that partitioning morphological characters by anatomical criteria generally has little influence on inferred phylogenetic topologies when branch lengths are linked across partitions. Models with unlinked branch lengths increase topological resolution but tend to reduce accuracy. The authors suggest that alternative partitioning strategies, such as those based on character homoplasy or evolutionary rates, may better capture morphological data heterogeneity than anatomical partitioning, and caution is advised when applying unlinked branch length models in morphological phylogenetics.