Abstract
Speciation – the process by which new species originate – is a fundamental process in evolutionary biology. Under the biological species concept, a species is a set of populations that are united by gene flow and which maintain independence from other such populations through the property of reproductive isolation. For this reason, the study of speciation has largely been equated with the study of genetic barriers to gene exchange between populations. Here, I describe an expanded framework for conceptualizing speciation that emphasizes key roles for processes other than reproductive isolation in the origins of biological diversity. These additional factors include those that affect the origin and persistence of demographically-isolated populations. I develop a general test for quantifying the contribution of these and other processes to the speciation, and I apply the framework to several vertebrate clades. I describe limits to our understanding of evolution that follow from a near-exclusive focus on reproductive isolation in speciation biology.

View YouTube video of seminar: https://youtu.be/kD1qEyO9p5Q