Large-scale Species Tree Estimation

Abstract

Species tree estimation is a complex problem, due to the fact that different parts of the genome can have different evolutionary histories than the genome itself. One of the causes for this discord is incomplete lineage sorting (also called deep coalescence), which is a population-level process that produces gene trees that differ from the species tree. The last decade has seen a large number of new methods developed to estimate species trees from multi-locus datasets, specifically addressing this cause of gene tree heterogeneity. In this paper, we review these methods, focusing mainly on issues that relate to analyses of datasets containing large numbers of species or loci (or both). We also discuss divide-and-conquer strategies for enabling species tree estimation methods to run on large datasets, including new approaches that are based on algorithms (such as TreeMerge) for the Disjoint Tree Merger problem.