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How Fitch-Margoliash Algorithm can Benefit from Multi Dimensional Scaling
Sylvain Lespinats1, Delphine Grando, Eric Maréchal
1UMR INSERM unité U722 and Université Denis Diderot-Paris 7, Faculté de médecine, site Xavier Bichat, 16 rue Henri Huchard, 75870 Paris cedex 18, France.
Evolutionary Bioinformatics Online
|June 24, 2011
Summary
This study explores how high-dimensional spaces affect phylogenetic reconstructions using the Fitch-Margoliash algorithm. New criteria improve distance preservation and robustness in evolutionary tree building.
Area of Science:
- Bioinformatics
- Computational Biology
- Evolutionary Biology
Background:
- Phylogenetic methods often represent genetic sequences as points in high-dimensional space.
- Studying evolutionary processes in these spaces involves challenges like the concentration of measured phenomena.
Purpose of the Study:
- To investigate the influence of high-dimensional space properties on phylogenetic reconstruction.
- To evaluate the Fitch-Margoliash algorithm, a Least Squares method, in this context.
Main Methods:
- Examined the relationship between Least Squares methods (Fitch-Margoliash) and Multi-Dimensional Scaling (MDS).
- Introduced concepts of "continuity" and "trustworthiness" to mitigate risks like "false neighborhoods" and "tears" in dimensionality reduction.
- Proposed new criteria for phylogeny construction.
Main Results:
- Least Squares methods for phylogeny are closely related to MDS.
- Identified "false neighborhood" and "tears" as key risks in dimensionality reduction for phylogenetics.
- Demonstrated that new criteria enhance distance preservation and robustness in phylogenetic trees.
Conclusions:
- Improvements in MDS can benefit Least Squares-based phylogenetic methods.
- Addressing dimensionality reduction risks is crucial for accurate evolutionary inference.
- The proposed criteria offer a more robust approach to building phylogenies, honoring Professor W.M. Fitch's legacy.
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