10:00 am Wednesday, September 18, 2019
Candidacy Talk: Geometric comparison of phylogenetic trees with different leaf sets by
Gill Grindstaff (UT Austin) in RLM 11.176
The metric space of phylogenetic trees defined by Billera, Holmes, and Vogtmann (BHV space), is a non-positively curved cube complex with combinatorial properties which provides a natural geometric setting for describing collections of trees on the same set of taxa. However, it is sometimes necessary to analyze collections of trees on non-identical taxa sets, and in this context it is not evident how to apply BHV techniques. Davidson et al. recently approached this problem by describing a combinatorial algorithm extending tree "topologies" to regions in higher dimensional tree spaces, so that one can quickly compute which topologies contain a given tree as partial data. In this talk, I'll present a refinement of their algorithm for metric trees, to give a full characterization of the space of extensions of a subtree as a subset of BHV. This algorithm can be used to define and search a space of possible supertrees and, for a collection of tree fragments with different leaf sets, to measure their compatibility. Submitted by
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