Department of Epidemiology and Biostatistics Seminar Series

Wednesday, May 8, 2024

2:00 PM-3:00 PM

At the next Department of Epidemiology and Biostatistics Seminar Series Peter Chi, PhD, Associate Professor of Statistics, Villanova University, will present "Improved Least Squares Phylogenetic Inference."

A phylogeny is an object that describes the evolutionary relationships between a group of species, and is also more informally known as an evolutionary tree. In addition to studying species, phylogenetics can also be used to study the evolution of pathogens such as bacteria and viruses, which can be instrumental in our understanding of how to control the diseases caused by them. In this talk, I will introduce a novel statistical methodology for inferring a phylogeny that is built upon the ordinary least squares framework. Specifically, we propose a new least squares loss function utilizing "robust distances" (O'Brien et al., 2009) in place of conventional genetic distances, and demonstrate gains to both branch length and topology estimation of phylogenies. I will include an example of utilizing this methodology on a dataset of HIV viral sequences extracted from a group of individuals within in one transmission chain, and discuss how the inferred phylogenetic tree compares to the known transmission chain.

Peter Chi completed his M.H.S. in Genetic Epidemiology at the Johns Hopkins Bloomberg School of Public Health, and PhD in Biostatistics at the University of Washington. His research is centered in statistical phylogenetics but he also has research interests in statistics education and the statistics of casino games. He is currently an Associate Professor of Statistics at Villanova University.

Contact Information

Nancy Colon-Anderson
nanderson@drexel.edu