An Evolving View of Species Tree Inference

Nearly all modern studies that address evolutionary questions require consideration of the phylogenetic relationships among species. But what, exactly, is a species tree? And how do we go about estimating such a tree from genomic data? In this Evolving View, I consider the historical development of the field of species tree inference and discuss both progress and controversies within the field at present. I conclude by suggesting future directions and highlighting challenges the field is likely to face in the coming years.