Recent advances in whole-genome studies provide increasingly strong evidence for a vital role of hybridization in the evolution of certain groups of species and allowing them to adapt to new environments. To represent such complex evolutionary histories as a web of life rather than a simple bifurcating tree of life, phylogenetic (evolutionary) networks have become a popular tool. In the context of reconstructing phylogenetic networks, the problem of characterizing and computing the minimum hybridization number for a set of phylogenetic trees has been investigated by many groups of researchers for the last 15 years. Roughly speaking, this minimum quantifies the number of hybridization events needed to explain a set of trees by simultaneously embedding them in a phylogenetic network. In this talk, we introduce cherry-picking sequences which are particular sequences on the leaves of the trees. We show how these sequences give a novel characterization of the minimum hybridization number for an arbitrarily large collection of phylogenetic trees. This is joint work with Peter Humphries and Charles Semple.
This is a seminar of the Combinatorial Mathematics Society of Australasia.
To attend email email@example.com with the subject 'subscribe' to receive zoom details. [You only need to subscribe once, not for future talks.]