 Of course, how biologists reconstruct a phylogeny and identify monophyletic groups is a matter of taxonomic freedom on the PhyloCode and other phylogenetic classifications. That’s just to say that phylogenetic inference will operate largely independently of these metaphysical and classificatory issues—except insofar as these classifications inform biologists about what it is that they are aiming to reconstruct a history of in the first place. Haber (2019) provides a framing for this challenge, arguing that the units of phylogeny are the units of divergence and diversification. Where Ereshefsky (2001) and other advocates of phylogenetic classification provide a specific way of cashing out those units, Haber describes this as a rich, general research project, similar to other “unit” problems in philosophy of biology. In much the same way that how we cash out, say, the units of selection may impact how we study or draw inferences about evolutionary processes, how we identify the units of divergence and diversification will impact how we draw inferences in phylogenetics. (See de Queiroz 2007 for related foundational issues.)