Biology – Quantitative Biology – Populations and Evolution
Scientific paper
2007-05-30
Biology
Quantitative Biology
Populations and Evolution
Scientific paper
In this paper we apply new geometric and combinatorial methods to the study of phylogenetic mixtures. The focus of the geometric approach is to describe the geometry of phylogenetic mixture distributions for the two state random cluster model, which is a generalization of the two state symmetric (CFN) model. In particular, we show that the set of mixture distributions forms a convex polytope and we calculate its dimension; corollaries include a simple criterion for when a mixture of branch lengths on the star tree can mimic the site pattern frequency vector of a resolved quartet tree. Furthermore, by computing volumes of polytopes we can clarify how ``common'' non-identifiable mixtures are under the CFN model. We also present a new combinatorial result which extends any identifiability result for a specific pair of trees of size six to arbitrary pairs of trees. Next we present a positive result showing identifiability of rates-across-sites models. Finally, we answer a question raised in a previous paper concerning ``mixed branch repulsion'' on trees larger than quartet trees under the CFN model.
Matsen Frederick A.
Mossel Elchanan
Steel Mike
No associations
LandOfFree
Mixed-up trees: the structure of phylogenetic mixtures does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mixed-up trees: the structure of phylogenetic mixtures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mixed-up trees: the structure of phylogenetic mixtures will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-356999