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Full-Text Articles in Genetics and Genomics
Does Direct Optimization Produce More Accurate Alignments And Topologies? Poy Vs. Clustalw+Paup*, T. Heath Ogden
Does Direct Optimization Produce More Accurate Alignments And Topologies? Poy Vs. Clustalw+Paup*, T. Heath Ogden
T. Heath Ogden
Direct optimization frameworks for simultaneously estimating alignments and phylogenies have recently been developed. One such method, implemented in the program POY, is becoming more common for analyses of variable length sequences (e.g., analyses using ribosomal genes) and for combined evidence analyses (morphology + multiple genes). Simulation of sequences containing insertion and deletion events was performed in order to directly compare a widely used method of multiple sequence alignment (ClustalW) and subsequent parsimony analysis in PAUP* with direct optimization via POY. Data sets were simulated for pectinate, balanced, and random tree shapes under different conditions (clocklike, non-clocklike, and ultrametric). Alignment accuracy …
How Should Gaps Be Treated In Parsimony? A Comparison Of Approaches Using Simulation, T. Heath Ogden
How Should Gaps Be Treated In Parsimony? A Comparison Of Approaches Using Simulation, T. Heath Ogden
T. Heath Ogden
Simulation with indels was used to produce alignments where true site homologies in DNA sequences were known; the gaps from these datasets were removed and the sequences were then aligned to produce hypothesized alignments. Both alignments were then analyzed under three widely used methods of treating gaps during tree reconstruction under the maximum parsimony principle. With the true alignments, for many cases (82%), there was no diVerence in topological accuracy for the diVerent methods of gap coding. However, in cases where a diVerence was present, coding gaps as a Wfth state character or as separate presence/absence characters outperformed treating gaps …