Fast FPT Algorithms for Computing Rooted Agreement Forests: Theory and Experiments

Extended Abstract
  • Chris Whidden
  • Robert G. Beiko
  • Norbert Zeh
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6049)


We improve on earlier FPT algorithms for computing a rooted maximum agreement forest (MAF) or a maximum acyclic agreement forest (MAAF) of a pair of phylogenetic trees. Their sizes give the subtree-prune-and-regraft (SPR) distance and the hybridization number of the trees, respectively. We introduce new branching rules that reduce the running time of the algorithms from O(3 k n) and O(3 k n logn) to O(2.42 k n) and O(2.42 k n logn), respectively. In practice, the speed up may be much more than predicted by the worst-case analysis. We confirm this intuition experimentally by computing MAFs for simulated trees and trees inferred from protein sequence data. We show that our algorithm is orders of magnitude faster and can handle much larger trees and SPR distances than the best previous methods, treeSAT and sprdist.


Search Tree Recursive Call Protein Tree Canada Research Chair Agreement Forest 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Chris Whidden
    • 1
  • Robert G. Beiko
    • 1
  • Norbert Zeh
    • 1
  1. 1.Faculty of Computer ScienceDalhousie UniversityHalifaxCanada

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