Letter to the Editor Bayesian Probabilities and Quartet Puzzling

نویسندگان

  • Korbinian Strimmer
  • Arndt von Haeseler
چکیده

Quartet puzzling (QP), a heuristic tree search procedure for maximum-likelihood trees, has recently been introduced (Strimmer and von Haeseler 1996). This method uses maximum-likelihood criteria for quartets of taxa which are then combined to form trees based on larger numbers of taxa. Thus, QP can be practically applied to data sets comprising a much greater number of taxa than can other search algorithms such as stepwise addition and subsequent branch swapping as implemented, e.g., in DNAML (Felsenstein 1993). However, its ability to reconstruct the true tree is less than that of DNAML (Strimmer and von Haeseler 1996). Here, we show that the assignment of penalties in the puzzling step of the QP algorithm is a special case of a more general Bayesian weighting scheme for quartet topologies. Application of this general framework leads to an improvement in the efficiency of QP at recovering the true tree as well as to better theoretical understanding of the method itself. On average, the accuracy of QP increases by 10% over all cases studied, without compromising speed or requiring more computer memory. Consider the three different fully-bifurcating tree topologies Q,, Q2, and Q3 for four taxa (fig. 1). Denote by ml, m2, and m3 their corresponding maximum-likelihood (not log-likelihood) values. Note that ml + m2 + m3 << 1. Evaluation via Bayes’ theorem of the three tree topologies given uniform prior information leads to posterior probabilities

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Phylogeny of shorebirds, gulls, and alcids (Aves: Charadrii) from the cytochrome-b gene: parsimony, Bayesian inference, minimum evolution, and quartet puzzling.

Charadrii (shorebirds, gulls, and alcids) have exceptional diversity in ecological, behavioral, and life-history traits. A phylogenetic framework is necessary to fully understand the relationships among these traits. Despite several attempts to resolve the phylogeny of the Charadrii, none have comprehensively utilized molecular sequence data. Complete and partial cytochrome-b gene sequences for...

متن کامل

Quartet Puzzling: A Quartet Maximum-Likelihood Method for Reconstructing Tree Topologies

A versatile method, quartet puzzling, is introduced to reconstruct the topology (branching pattern) of a phylogenetic tree based on DNA or amino acid sequence data. This method applies maximum-likelihood tree reconstruction to all possible quartets that can be formed from n sequences. The quartet trees serve as starting points to reconstruct a set of optimal n-taxon trees. The majority rule con...

متن کامل

Short Quartet Puzzling: A New Quartet-Based Phylogeny Reconstruction Algorithm

Quartet-based phylogeny reconstruction methods, such as Quartet Puzzling, were introduced in the hope that they might be competitive with maximum likelihood methods, without being as computationally intensive. However, despite the numerous quartet-based methods that have been developed, their performance in simulation has been disappointing. In particular, Ranwez and Gascuel, the developers of ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1998