2007

Abstract:

Phylogenetics is the field of science which deals with the study of evolutionary relatedness between species. However, the mathematical study of phylogenetics has only just begun. In this talk, I will discuss some interesting results and applications of mathematical phylogenetics. To begin with, I will give a new formulation of homoplasy, a fundamental concept in phylogenetics. In particular, I will show that homoplasy can be conceptualized in terms of subtree-prune and regrafts, a re-arrangement operation for phylogenetic trees. Based on this concept, I will then describe a simple way of measuring evolutionary relatedness between two characters, called generalized incompatibility. The notion of incompatibility is then used to develop a robust non-parametric statistical test for detecting recombination (an important biological process through which genetic information is exchanged between viral strains for instance). Time permitting, I will discuss how the statistical test helps reveal the role of recombination in FIV, an important pathogen.