Bayesian Estimation of Concordance among Gene Trees

Authors: Ané, Cécile; Larget, Bret; Baum, David A.; Smith, Stacey D.; Rokas, Antonis

Source: Molecular Biology and Evolution, Volume 24, Number 2, February 2007 , pp. 412-426(15)

Buy & download fulltext article:

Price: $42.29 plus tax (Refund Policy)

Abstract:

Multigene sequence data have great potential for elucidating important and interesting evolutionary processes, but statistical methods for extracting information from such data remain limited. Although various biological processes may cause different genes to have different genealogical histories (and hence different tree topologies), we also may expect that the number of distinct topologies among a set of genes is relatively small compared with the number of possible topologies. Therefore evidence about the tree topology for one gene should influence our inferences of the tree topology on a different gene, but to what extent? In this paper, we present a new approach for modeling and estimating concordance among a set of gene trees given aligned molecular sequence data. Our approach introduces a one-parameter probability distribution to describe the prior distribution of concordance among gene trees. We describe a novel 2-stage Markov chain Monte Carlo (MCMC) method that first obtains independent Bayesian posterior probability distributions for individual genes using standard methods. These posterior distributions are then used as input for a second MCMC procedure that estimates a posterior distribution of gene-to-tree maps (GTMs). The posterior distribution of GTMs can then be summarized to provide revised posterior probability distributions for each gene (taking account of concordance) and to allow estimation of the proportion of the sampled genes for which any given clade is true (the sample-wide concordance factor). Further, under the assumption that the sampled genes are drawn randomly from a genome of known size, we show how one can obtain an estimate, with credibility intervals, on the proportion of the entire genome for which a clade is true (the genome-wide concordance factor). We demonstrate the method on a set of 106 genes from 8 yeast species.

Keywords: gene genealogy; concordance; Bayesian phylogenetics; total evidence; consensus methods; Dirichlet process

Document Type: Research article

DOI: http://dx.doi.org/10.1093/molbev/msl170

Publication date: 2007-02-01

More about this publication?

Molecular Biology and Evolution publishes research at the interface between molecular and evolutionary biology. The journal publishes investigations of molecular evolutionary patterns and processes, tests of evolutionary hypotheses that use molecular data, and studies that use molecular evolutionary information to address questions about biological function at all levels of organization.

Bayesian Estimation of Concordance among Gene Trees

Buy & download fulltext article:

Tools

Key

Text size:

Useful pages