TY - JOUR

T1 - Reconstructing phylogenies from noisy quartets in polynomial time with a high success probability

AU - Wu, Gang

AU - Kao, Ming-Yang

AU - Lin, Guohui

AU - You, Jia Huai

N1 - Funding Information:
The research of GW, GL, and JHY is partially supported by NSERC. GL is also supported by CFI. JHY is also supported by NSFC 60673009. We thank the anonymous reviewers for their extremely helpful comments.

PY - 2008/1/24

Y1 - 2008/1/24

N2 - Background: In recent years, quartet-based phylogeny reconstruction methods have received considerable attentions in the computational biology community. Traditionally, the accuracy of a phylogeny reconstruction method is measured by simulations on synthetic datasets with known "true" phylogenies, while little theoretical analysis has been done. In this paper, we present a new model-based approach to measuring the accuracy of a quartet-based phylogeny reconstruction method. Under this model, we propose three efficient algorithms to reconstruct the "true" phylogeny with a high success probability. Results: The first algorithm can reconstruct the "true" phylogeny from the input quartet topology set without quartet errors in O(n2) time by querying at most (n - 4) log(n - 1) quartet topologies, where n is the number of the taxa. When the input quartet topology set contains errors, the second algorithm can reconstruct the "true" phylogeny with a probability approximately 1 - p in O(n4log n) time, where p is the probability for a quartet topology being an error. This probability is improved by the third algorithm to approximately 1/1+q2+1/2q4 +1/16q5, where q=p/1-p with running time of O(n5), which is at least 0.984 when p < 0.05. Conclusion: The three proposed algorithms are mathematically guaranteed to reconstruct the "true " phylogeny with a high success probability. The experimental results showed that the third algorithm produced phylogenies with a higher probability than its aforementioned theoretical lower bound and outperformed some existing phylogeny reconstruction methods in both speed and accuracy.

AB - Background: In recent years, quartet-based phylogeny reconstruction methods have received considerable attentions in the computational biology community. Traditionally, the accuracy of a phylogeny reconstruction method is measured by simulations on synthetic datasets with known "true" phylogenies, while little theoretical analysis has been done. In this paper, we present a new model-based approach to measuring the accuracy of a quartet-based phylogeny reconstruction method. Under this model, we propose three efficient algorithms to reconstruct the "true" phylogeny with a high success probability. Results: The first algorithm can reconstruct the "true" phylogeny from the input quartet topology set without quartet errors in O(n2) time by querying at most (n - 4) log(n - 1) quartet topologies, where n is the number of the taxa. When the input quartet topology set contains errors, the second algorithm can reconstruct the "true" phylogeny with a probability approximately 1 - p in O(n4log n) time, where p is the probability for a quartet topology being an error. This probability is improved by the third algorithm to approximately 1/1+q2+1/2q4 +1/16q5, where q=p/1-p with running time of O(n5), which is at least 0.984 when p < 0.05. Conclusion: The three proposed algorithms are mathematically guaranteed to reconstruct the "true " phylogeny with a high success probability. The experimental results showed that the third algorithm produced phylogenies with a higher probability than its aforementioned theoretical lower bound and outperformed some existing phylogeny reconstruction methods in both speed and accuracy.

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U2 - 10.1186/1748-7188-3-1

DO - 10.1186/1748-7188-3-1

M3 - Article

C2 - 18218120

AN - SCOPUS:40649125833

SN - 1748-7188

VL - 3

JO - Algorithms for Molecular Biology

JF - Algorithms for Molecular Biology

IS - 1

M1 - 1

ER -