 As philosophers of science are well aware, idealization in science is both common and serves important purposes (e.g., Cartwright 1983; McMullin 1985; Wimsatt 2007; Weisberg 2007). Yet, it can be fruitful to pause and consider if some of these idealizations and simplifying assumptions need to be re-examined, are hindering studies, or generating other road blocks. Indeed, that’s precisely what has happened recently in phylogenetics. Re-examining the utility of simplifying assumptions in phylogenetics has come both from outside the field (particularly from microbiology) and internally (as phylogeneticists began to appreciate what might be gained from incorporating more complexity). This is (or, at least, can be) a good and healthy thing for a science. It puts pressure on scientists and philosophers to further articulate the central commitments of a science, and to consider how to account for new challenges. Challenges can also push a science to adapt and revise those central commitments as new evidence, theories, and tools are discovered or developed, or to revisit the utility of underlying simplifying assumptions and idealizations. This, in turn, helps philosophers of science understand how science can advance. (Haber 2019 describes this in the context of phylogenetics as productive disruptions.)