Constructing the Simplest Possible Phylogenetic Network from Triplets

  • Leo van Iersel
  • Steven Kelk
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5369)


A phylogenetic network is a directed acyclic graph that visualises an evolutionary history containing so-called reticulations such as recombinations, hybridisations or lateral gene transfers. Here we consider the construction of a simplest possible phylogenetic network consistent with an input set T, where T contains at least one phylogenetic tree on three leaves (a triplet) for each combination of three taxa. To quantify the complexity of a network we consider both the total number of reticulations and the number of reticulations per biconnected component, called the level of the network. We give polynomial-time algorithms for constructing a level-1 respectively a level-2 network that contains a minimum number of reticulations and is consistent with T (if such a network exists). In addition, we show that if T is precisely equal to the set of triplets consistent with some network, then we can construct such a network, which minimises both the level and the total number of reticulations, in time O(|T| k + 1), if k is a fixed upper bound on the level.


Directed Acyclic Graph Lateral Gene Transfer Optimal Network Simple Network Phylogenetic Network 
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 2008

Authors and Affiliations

  • Leo van Iersel
    • 1
  • Steven Kelk
    • 2
  1. 1.Department of Mathematics and Computer ScienceTechnische Universiteit EindhovenEindhovenThe Netherlands
  2. 2.Centrum voor Wiskunde en Informatica (CWI)AmsterdamThe Netherlands

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