Phylogeny as population history

The construction and use of phylogenetic trees is central to modern systematics. But it is unclear exactly what phylogenies and phylogenetic trees represent. They are sometimes said to represent genealogical relationships between taxa, between species, or simply between “groups of organisms.” But these are incompatible representational claims. This paper focuses on how trees are used to make inferences and then argues that this focus requires that phylogenies represent the histories of populations.