Phylogenies play a central role in biology. They have had a revolutionary effect in evolutionary biology where they are used to address questions such as the history of cospeciation between hosts and parasites, the timing of the major events of the diversification of life, and the evolution of ecologically important characters. Phylogenies also serve as an important tool in medicine. For example, phylogenies are widely used in epidemiology, where among other applications they have been used to establish the origin and timing of the HIV epidemic in humans. However, modem genomics, with its enormous quantity and high quality of genetic data, poses significant challenges to the field of phylogenetics: how can one make sense of genomic data in a phylogenetic context and how can these data be used to address interesting and important questions, such as the functional importance of amino acid positions? Bayesian estimation of phylogeny represents one of the most promising recent developments in the field. In this proposal, theory and methods will be developed that will extend Bayesian analysis of genetic data in several important ways. First, methods capable of identifying site and branch combinations under positive selection will be developed. These methods will expand the traditional codon models of DNA substitution to allow switching between selection classes. Second, improved methods of Bayesian inference will be developed for estimating large phylogenetic trees. The improvements will involve variants of Markov chain Monte Carlo that better explore the space of trees. Third, Bayesian methods for estimating divergence times will be developed. These methods will accommodate uncertainty in the phylogenetic tree, model parameters, and calibration times when estimating divergence times of pre-specified groups of species (or viral sequences). Finally, new methods for predicting RNA secondary structure will be developed. The method will combine information from comparative sequence analysis and the Gibb's free energy.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM069801-02
Application #
6920005
Study Section
Genetics Study Section (GEN)
Program Officer
Eckstrand, Irene A
Project Start
2004-08-01
Project End
2008-07-31
Budget Start
2005-08-01
Budget End
2006-07-31
Support Year
2
Fiscal Year
2005
Total Cost
$227,976
Indirect Cost
Name
University of California San Diego
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Schraiber, Joshua G; Landis, Michael J (2015) Sensitivity of quantitative traits to mutational effects and number of loci. Theor Popul Biol 102:85-93
Boussau, Bastien; Walton, Zaak; Delgado, Juan A et al. (2014) Strepsiptera, phylogenomics and the long branch attraction problem. PLoS One 9:e107709
Höhna, Sebastian; Heath, Tracy A; Boussau, Bastien et al. (2014) Probabilistic graphical model representation in phylogenetics. Syst Biol 63:753-71
Landis, Michael J; Bedford, Trevor (2014) Phylowood: interactive web-based animations of biogeographic and phylogeographic histories. Bioinformatics 30:123-4
Heath, Tracy A; Huelsenbeck, John P; Stadler, Tanja (2014) The fossilized birth-death process for coherent calibration of divergence-time estimates. Proc Natl Acad Sci U S A 111:E2957-66
Landis, Michael J; Matzke, Nicholas J; Moore, Brian R et al. (2013) Bayesian analysis of biogeography when the number of areas is large. Syst Biol 62:789-804
Nasrallah, Chris A; Huelsenbeck, John P (2013) A phylogenetic model for the detection of epistatic interactions. Mol Biol Evol 30:2197-208
Landis, Michael J; Schraiber, Joshua G; Liang, Mason (2013) Phylogenetic analysis using Lévy processes: finding jumps in the evolution of continuous traits. Syst Biol 62:193-204
Nasrallah, Chris A (2013) The dynamics of alternative pathways to compensatory substitution. BMC Bioinformatics 14 Suppl 15:S2
Barnosky, Anthony D; Hadly, Elizabeth A; Bascompte, Jordi et al. (2012) Approaching a state shift in Earth's biosphere. Nature 486:52-8

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