Supplement for Improved Variational Bayesian Phylogenetic Inference with Normalizing Flows A Subsplit Bayesian networks D AB C AB CD ABC D ABC D AB CD D AB CD AB CD AB CD assign

Figure 1: A simple subsplit Bayesian network for a leaf set that contains 4 species A, B, C and D. This figure is adapted from Zhang and Matsen IV (2019). SBN (the one with a full and complete binary tree structure as shown in Figure 1) is good enough. The SBN framework also generalizes to unrooted trees, which are the most common type of phylogenetic trees. (Zhang and Matsen IV, 2018). Sampling from SBNs is also straightforward via ancestral sampling.