Fast Compatibility Testing for Phylogenies with Nested Taxa

Abstract

Semi-labeled trees are phylogenies whose internal nodes may be labeled by higher-order taxa. Thus, a leaf labeled Mus musculus could nest within a subtree whose root node is labeled Rodentia, which itself could nest within a subtree whose root is labeled Mammalia. Suppose we are given collection $\mathcal{P}$ of semi-labeled trees over various subsets of a set of taxa. The ancestral compatibility problem asks whether there is a semi-labeled tree $\mathcal{T}$ that respects the clusterings and the ancestor/descendant relationships implied by the trees in $\mathcal{P}$. We give a $\tilde{O}(M_{\mathcal{P}})$ algorithm for the ancestral compatibility problem, where $M_{\mathcal{P}}$ is the total number of nodes and edges in the trees in $\mathcal{P}$. Unlike the best previous algorithm, the running time of our method does not depend on the degrees of the nodes in the input trees.

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