Noisy: Identification of problematic columns in multiple sequence alignments

Motivation: Sequence-based methods for phylogenetic reconstruction from (nucleic acid) sequence data are notoriously plagued by two effects: homoplasies and alignment errors. Large evolutionary distances imply a large number of homoplastic sites. As most protein-coding genes show dramatic variations in substitution rates that are not uncorrelated across the sequence, this often leads to a patchwork pattern of (i) phylogenetically informative and (ii) effectively randomized regions. In highly variable regions, furthermore, alignment errors accumulate resulting in sometimes misleading signals in phylogenetic reconstruction. Results: We present here a method that, based on assessing the distribution of character states along a cyclic ordering of the taxa, allows the identification of phylogenetically uninformative homoplastic sites in a multiple sequence alignment. Removal of these sites appears to improve the performance of phylogenetic reconstruction algorithms as measured by various i...

• Type: Journal
• Year: 2008
• Where: ALMOB
• Authors: Andreas W. M. Dress, Christoph Flamm, Guido Fritzsch, Stefan Grünewald, Matthias Kruspe, Sonja J. Prohaska, Peter F. Stadler
• Keywords: ALMOB 2008, Homoplastic Sites, Large Evolutionary Distances, Phylogenetic Reconstruction