Biology Seminar | Professor Lacey Knowles, University of Michigan | What’s missing from the speciation continuum and why it matters

As someone whose work is rooted in studying the demographic controls of genetic variation and divergence within species and across communities of species, my interest in speciation builds from this foundation. In today's talk I will argue for the importance of expanding the focus of speciation research to include not only a focus on the mechanistic causes of speciation (whether genetic or ecological) that determine the fate of incipient divergences, but also the opportunities for speciation - that is, the initiation and persistence of population divergence. I'll present an empirical example in which population persistence, rather than chromosomal rearrangements, may be key to understanding the controls on diversification in a tropical rodent. I then shift gears and present models we have/are developing for quantifying biodiversity while explicitly accounting for the hierarchical process of speciation - namely, the incipient stages of divergence and the persistence of lineages we recognize as species. I will touch upon the limitations of studying species lineages alone to quantify biodiversity. The works I present reflects recent calls for expanding the focus of speciation research. This includes a fundamental shift in that both species lineages and the incipient divergences (i.e., population isolation) within species lineages should be studied to understand why species diversity varies across space, time, and among taxa.