INVESTIGADORES
RAMIREZ Martin Javier
capítulos de libros
Título:
Parsimony methods
Autor/es:
RAMIREZ, M.J,
Libro:
eLS
Editorial:
John Wiley and Sons
Referencias:
Año: 2013; p. 1 - 13
Resumen:
Parsimony methods of phylogenetic reconstruction use an explicit criterion of optimality, the minimization of evolutionary transformations. By doing so, parsimony also minimizes instances of homoplasy (convergence or parallelisms) and maximizes similarity due to common descent (homology). Tree evaluation is done by an optimization algorithm that calculates the length of each character over the tree; the global tree length is the sum of the individual character lengths. The Sankoff generalized algorithm allows for the optimization of characters with any cost matrices; there are faster algorithms specific for unordered and additive characters. A problem with tree searches is the vast number of possible trees. There are exact solutions only for small datasets, but most real datasets require heuristic strategies. Measures of group support show the degree on which the data hold the conclusions, and sensitivity analyses help express the robustness of phylogenetic inferences upon changes in parameters and conditions of analysis