# Edward Susko (Dalhousie University)

## Lauréat du Prix CRM-SSC 2011 / CRM-SSC 2011 Prize Recipient

Le vendredi 9 septembre 2011 / Friday, September 9, 2011

Université de Montréal, Pav. André-Aisenstadt, 2920, chemin de la Tour,

SALLE 1360

15 h 30 - 16 h 30 / 3:30 p.m. - 4:30 p.m.

## Properties of Bayesian Posteriors and Bootstrap Support in Phylogenetic Inference

### Résumé / Abstract:

The data generated by large scale sequencing projects is complex, high-dimensional,

multivariate discrete data. In studies of evolutionary biology, the parameter space

of evolutionary trees is an unusual additional complication from a statistical

perspective. In this talk I will briefly introduce the general approaches to

utilizing sequence data in phylogenetic inference.

A particular issue of interest in phylogenetic inference is assessments of uncertainty

about the true tree or structures that might be present in it. The primary way in

which uncertainty is assessed in practice is through bootstrap support (BP) for

splits, large values indicating strong support for the split. A difficulty with this

measure, however, has been deciding how large is large enough. We discuss the

interpretation of BP and ways of adjusting it so that it has an interpretation similar

to a p-value. A related issue, having to do with the behaviour of methods when data

are generated from a star tree, gives rise to an interesting example in which, due to

the unusual statistical nature, Bayesian and